There are animal data that indicate that prenatal environmental exposures have sex-specific effects on subsequent generations. In humans, an increase in birthweight has been reported if the maternal grandmother had smoked in the pregnancy giving rise to the mother. Here we assess whether prenatal exposure of either parent to cigarette smoke has a sex-specific effect on the grandchild's birth measurements.Information from 12707 maternal and 9677 paternal grandmothers of children in the Avon Longitudinal Study of Parents and Children (ALSPAC) concerned whether they had smoked while expecting the study parent. Study children were weighed and measured at birth. Analyses to test effects of grandmaternal prenatal smoking used multiple regression allowing for several potential confounders; analyses were restricted to births to non-smoking study mothers.2. Similar effects were seen in births to primiparae and multiparae. Additional allowance for maternal birthweight resulted in an average increase in boys to +100 g  g. There were no fetal growth differences if the paternal grandmother had smoked prenatally.After adjustment, the average birthweight, birth length and BMI measurements of the grandsons (but not granddaughters) were greater if the maternal grandmother smoked prenatally: birthweight  = +61  g; birth length  = +0·19  cm; BMI  = +1·6  g/mThe evidence from this study suggests that when the mother does not smoke in pregnancy the maternal grandmother's smoking habit in pregnancy has a positive association with her grandson's fetal growth. This study of transgenerational effects was instigated following studies from Sweden based on samples of individuals born in the town of Överkalix in specified years. Their longevity and other health outcomes were linked to detailed historical records of harvests experienced by their ancestors. Analyses using three independent cohorts showed that the paternal grandfathers' plentiful food supply in mid-childhood was associated with a four-fold increased chance of diabetes on the grandchild's death certificate Although increasing interest is being shown in transgenerational effects on growth and development, few studies have looked at effects on fetal growth. Adult mortality is known to be associated with birthweight differentially by cause of death in utero, but no allowance was made for parity and the measurement of birthweight tended to be rounded to the nearest 4 oz. before conversion to gm In this paper we use maternal prenatal cigarette smoking as our exemplar since it has strong effects on fetal growth. However it is not clear whether there is an effect on the subsequent generations. Only three studies to our knowledge have looked at possible transgenerational effects in regard to prenatal smoking. Misra and colleagues in utero, contingent on their own smoking habits in pregnancy.The aim of the present study is therefore to determine whether prenatal smoke exposure of either of the study child's parents influences the growth of the fetus – and to determine, in particular, whether any effect varies with the child's gender. We analyse data in regard to maternal smoking in pregnancy across two generations using the Avon Longitudinal Study of Parents and Childhood (ALSPAC) and consider fetal growth in regard to whether the study parents were exposed Ethical approval for the study was obtained from the ALSPAC Law and Ethics Committee and the Local Research Ethics Committees.st April 1991 and 31st December 1992, were invited to take part. About 80% of the eligible population did so The data used in these analyses were collected as part of the Avon Longitudinal Study of Parents and Children (ALSPAC), which was designed to assess the ways in which the environment interacts with the genotype to influence health and development Information collected from the parents during their study pregnancy included details of the maternal and paternal grandparents. The women and their partners were sent a number of questionnaires during pregnancy. These elicited information on their current smoking habits and those of their parents (i.e. the study grandparents). If they reported that their mothers had smoked, they were asked whether their mothers had smoked when expecting them – and, if so, were given the responses yes/no/don't know from which to select. Thus the parents who replied ‘don't know’, had a mother who smoked but the parent was unsure whether she had smoked during her pregnancy. We have analysed these data in two ways: (a) assuming that all these women did smoke during pregnancy, and (b) omitting the ‘don't knows’ from the analyses and only analysing those definitely reporting smoking status during the study pregnancy [this we have treated as a sensitivity analysis]. All mothers who themselves smoked during the study pregnancy were excluded from these analyses. Consequently we compared two groups of grandchildren: those whose grandmothers had smoked during the pregnancy resulting in their parent but whose mothers had not smoked with those whose parents had not smoked [MGM+M- with MGM–M- and PGM+M- with PGM–M-] respectively.Other data used in the analyses include the study mother's parity ; gestation ; mother's partner smoking in pregnancy ; maternal age at the birth of the child (continuous); housing tenure as a measure of socioeconomic background , maternal education , maternal alcohol consumption when the mother first felt the baby move . Maternal birth weight was added as a separate confounder for a subsequent analysis.2 (g/m2).At delivery the baby was weighed to the nearest gram; ALSPAC study staff visited the two main delivery hospitals each day and measured the crown-heel length and head circumference of available infants in a standardised manner In this study we have used Body Mass Index (BMI), rather than ponderal index (PI) as our measure of adiposity at birth for two reasons: (a) subsequent analyses will assess whether the association with birth BMI is reflected in childhood measures of adiposity, where BMI is more relevant; (b) although it is traditional to use PI at birth, there is little literature to justify this. It has been suggested that the criteria used to choose whether to use PI or BMI should be a measure that is independent of length Multivariable linear regression models assessed the grandchildren's adjusted mean birthweight, crown-heel length, head circumference and BMI by parental prenatal smoking exposure. All models were adjusted for maternal parity, maternal education, paternal smoking at the start of pregnancy and gestation with MGM-M- (or PGM-M-) as the reference categories. Additional models adjusted for maternal age, housing tenure and maternal alcohol use as well as maternal birthweight. Separate models were produced for each grandchild's sex and maternal parity. We tested any potential interaction between grandmaternal smoking and gender by entering interaction terms into a non-stratified (for gender) model.Data on the smoking status of the maternal and paternal grandmothers when pregnant with the study mothers and fathers were available for 12707 and 9677 study children respectively . CombiniThe distributions of factors that are known to be associated with fetal growth are compared for those with and without a history of prenatal exposure of the mother [MGM+ and MGM–] and the father [PGM+ and PGM–] in Compared to those with no data at all on MGM smoking, those with data were very similar . However2 but not of the girls [P for interaction  = 0.026]. These effects were robust to adjustment, and remained when the unknown status of pregnancy smoking of the grandmothers was omitted. Additional adjustment for maternal age, housing tenure and maternal alcohol use showed no difference in the results (data not shown). However further adjustment for maternal birthweight resulted in an increased effect in the birthweight of the boys from +61 g to +100 g  g; and for girls an increase from +14 g to +34  g. A further analysis repeated that in Excluding information from pregnancies where the mother had smoked, the unadjusted mean birthweight of the boy infants was higher if the maternal grandmother had smoked during pregnancy  g compared to those who did not smoke; this was only moderately attenuated upon adjustment  g . There wIn contrast with the maternal grandmothers, the smoking status of paternal grandmothers did not appear to have any influence on the birth measurements of either sons or daughters .The study of Misra et al 2, whereas the girls did not: mean difference in birthweight  g, birth length  cm and BMI  g/m2.We have shown that when the mother does not smoke in pregnancy, there appears to be a discernible effect on her offspring of her own prenatal exposure. This was associated with an increased mean birthweight, birth length and BMI for her sons but not daughters, even after adjusting for factors such as maternal age, parity, socio-economic factors, and alcohol consumption. Similar associations were shown for children born to primiparae and those born to multiparae. The effect sizes for these associations were similar when sensitivity analyses restricted the information to those grandmothers who were definitely smoking during the mother's pregnancy (data not shown). In this study we did not control for maternal height, weight or BMI, nor for maternal birthweight as part of our primary analyses as we considered this likely to be an over-control. Nevertheless as part of a sensitivity analysis we repeated the analyses in Our robust results on birthweight reflect those from three previous studies of maternal prenatal exposure to cigarette smoking, although none analysed their data separately for offspring sex offspring of the prenatally exposed individual; currently there are no comparable reports in humans. The nearest comes from the Överkalix historical studies, which show an association of the food supply during the prenatal development of the paternal grandmother with the mortality rate of her granddaughters but not grandsons, indicating that transmission is through the son [but not the daughter] of the woman prenatally exposed offspring of these F1 females  had diminished lung function. In both the F1 and F2 offspring the males were more severely affected and tracheal constriction in response to acetylcholine was only seen in males, a sex-specific effect supported by increased tracheal fibronectin expression and other protein markers of tracheal responsiveness.It is not unusual for prenatal exposures to have differential sex effects. Maternal smoking has been associated with a greater growth reduction during fetal development in the male as compared with the female fetus in utero, raise the question as to possible mechanisms. Misra et al in utero; this would be expected to alter metabolic signals to her oocytes or across the placenta, thus influencing the growth of her own sons; (ii) a direct effect of grandmaternal smoking on oogenesis in the mother when she was a fetus; (iii) a combination of (i) and (ii).The findings in the literature increase in birthweight and birth length of sons, even though maternal smoking produces a decrease in birthweight. This reversal in the outcome suggests an adaptive response down the generations, perhaps through mechanism (iii) above. Why such an adaptive response just affects sons is unclear. A recent review of sexual dimorphism emphasises In interpreting their finding of nicotine exposure producing comparable asthma outcomes in F1 and F2 generations in rats, Rehan et al It is worth noting that, in our study, the son's only X chromosome was exposed (during the mother's development), whilst daughters have both an exposed X from mother and a less/unexposed X from father. There is likely to be selection against sperm carrying the most chromosomal damage should the father be a smoker. Dosage compensation in females through X inactivation  might provide a mechanism for limiting the ‘adaptive’ increase in fetal growth in females.in utero to be heavier than controls, whilst second and third born were lighter at birth. This context dependence is suggestive of adaptive responses.Transgenerational adaptation to adverse exposures has been demonstrated in rodents, the most striking demonstrating increased protection against liver fibrosis down the  generations The present study has the following strengths: (i) it is based on a large geographic population; (ii) information on parental and grandparental smoking was obtained prior to the birth of the study offspring, and therefore was not biased by the pregnancy outcome; (iii) birth measurements of the study child were obtained using standardised methods, which enabled accurate analyses of birth length and birth BMI; (iv) information on paternal prenatal exposures served as a comparison group. The transgenerational effect of maternal prenatal smoke exposure may have been socially patterned in some way, but if social patterning explained our findings one would expect a similar association with paternal exposure, yet this was not observed.The study mothers were born between 1945 and 1975 and the fathers between 1902 and 1976. It should be remembered that smoking in pregnancy was first formally recognised as having possible adverse effects on fetal growth in 1957 The disadvantage with this study is that although the data on prenatal smoking were collected from each of the study parents, no attempt was made at validation; however, the relationship between prenatal exposure and birthweight of the study parent and of the child showed predictive validity in regard to fetal growth (i.e. the birthweights of parents who were said to have smoked were lower than those who had said that they had not smoked – data not shown). We have not, as yet, been able to compare our sex- specific outcomes with those from another study although the overall results were similar to those of two other studies We have shown that the non-smoking mother's own prenatal exposure to cigarette smoke is associated with an increased birthweight, and an increased birth BMI of the male offspring. This raises the question as to whether such an association continues throughout childhood and adolescence.Table S1Mean difference [95% CI] in birth measurements of children born to non-smoking mothers, comparing those where the child's grandmother had smoked with those who had not when the child is the mother's firstborn.(DOCX)Click here for additional data file.Table S2Mean difference [95% CI] in birth measurements of children born to non-smoking mothers, comparing those where the child's grandmother had smoked with those who had not when the child is NOT the mother's firstborn.(DOCX)Click here for additional data file.


Previous animal studies have shown that perfluorinated compounds (PFCs) have adverse impacts on birth outcomes, but the results have been inconclusive in humans. We investigated associations between prenatal exposure to perfluorooctanoic acid (PFOA), perfluorooctyl sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUA) and birth outcomes.In total, 429 mother-infant pairs were recruited from the Taiwan Birth Panel Study (TBPS). Demographic data were obtained by interviewing mothers using a structured questionnaire and birth outcomes were extracted from medical records. Cord blood was collected for PFOA, PFOS, PFNA, and PFUA analysis by ultra-high-performance liquid chromatography/tandem mass spectrometry.β  = −0.37  wks, −110.2  gm and −0.25  cm]. Additionally, the odds ratio of preterm birth, low birth weight, and small for gestational age increased with PFOS exposure . When PFOS levels were divided into quartiles, a dose-response relation was observed. However, PFOA, PFNA, and PFUA were not observed to have any convincing impact on birth outcomes.The geometric mean (standard deviation) levels of PFOA, PFOS, PFNA, and PFUA in cord blood plasma were 1.84 (2.23), 5.94 (1.95), 2.36(4.74), and 10.26 (3.07) ng/mL, respectively. Only PFOS levels were found to be inversely associated with gestational age, birth weight, and head circumference [per ln unit: adjusted An adverse dose-dependent association was observed between prenatal PFOS exposure and birth outcomes. However, no associations were found for the other examined PFCs. Perfluorinated compounds (PFCs) are persistent organic pollutants consisting of a carbon backbone, typically 4–14 carbons long, and a charged function moiety. Since they were first produced in the 1950 s, PFCs have been used in a variety of consumer and industrial products PFCs have been reported to exhibit developmental toxicity in addition to hepatotoxicity, immunotoxicity, hormone disturbances, and tumorigenic potential in utero exposure. Participants were recruited from a longitudinal birth cohort established between 2004 and 2005 in northern Taiwan, and their samples were analyzed for the following four PFCs: PFOA and PFOS (both 8-carbon products), PFNA (a 9-carbon product), and perfluoroundecanoic acid . The impacts of these four PFCs on birth outcomes, including gestational age, birth weight, birth length, head circumference, Ponderal index, preterm birth, and small for gestational age, were investigated.Maternal-fetal PFCs transfer had been documented in animal models and human studies Mothers provided written informed consent for themselves and their babies to participate in the study. The Research Ethics Committee of Taiwan National University Hospital approved the protocol. All aspects of data collection and storage were in accordance with the standards stipulated by this approval.The study subjects were from the Taiwan Birth Panel Study (TBPS), a longitudinal birth cohort study that was conducted at one medical center in Taipei and one local hospital and two clinics in New Taipei from April 2004 to January 2005. Mothers were interviewed by trained interviewers using a structured prenatal questionnaire during the postpartum hospital stay. Cord blood was collected at birth and stored at −80°C until required for laboratory analysis. A total of 439 mother-infant pairs were initially enrolled. Infants with incomplete records of birth weight (n = 2) and birth length (n = 2) were excluded. Furthermore, 5 active smokers and 1 mother with unknown environmental tobacco smoke (ETS) exposure status during pregnancy were also excluded. Finally, 429 mother-infant pairs constituted the study cohort.Our previous study had developed a fast and sensitive ultra-high-performance liquid chromatography/tandem mass spectrometry method using the Waters ACQUITY UPLC system  coupled with a Waters Quattro Premier XE triple quadrupole mass spectrometer for the determination of twelve PFCs in cord blood 3), preterm birth, low birth weight and small for gestational age at birth. All of the data were extracted from medical records. Gestational age was assessed by obstetricians based on last menstruation or early ultrasound estimates; other measurements were obtained by trained nurses. The Ponderal index was calculated by dividing birth weight (grams) by the third power of birth length (centimeters) and multiplying the result by 100. Preterm birth was defined as a gestational age <37 weeks. Low birth weight was defined as a birth weight <2,500 gm. A birth weight below the 10th percentile for gestational age was classified as small for gestational age. Birth weight for gestational age was determined using the percentile scale derived from national Taiwanese data The birth outcomes examined in this study were the following: gestational age (weeks), birth weight (grams), birth length (centimeters), head circumference (centimeters), Ponderal index  coupled to a triple quadruple tandem spectrometer . The limit of detection of cord blood cotinine was 0.05 ng/mL. The original levels were natural log transformed due to a right-skewed distribution.2), normal weight (BMI 18.5–24.9 kg/m2), and overweight (BMI ≥25.0 kg/m2).The other potential confounders were obtained using the structured prenatal questionnaire. These confounders were selected a priori according to the reported literature P values of <0.05.Initially, the distributions of PFC levels in mothers and infants with different characteristics were compared using Wilcoxon’s rank sum test and the Kruskal Wallis test. The levels of PFOA, PFOS, PFNA, and PFUA were then natural log transformed due to a right-skewed distribution. Correlations between the levels of the four PFCs were determined using Pearson’s correlation, and correlation coefficients were <0.45; thus, their influences on birth outcomes were analyzed separately. Simple and multiple linear regression models were used to explore the associations between PFCs levels in cord blood plasma and gestational age, birth weight, length, head circumference, and Ponderal index. Additionally, the influence of PFCs levels on preterm birth, low birth weight and small for gestational age was investigated by logistic regression. The potential confounders, namely maternal age, prepregnancy BMI, education level, log (Ln)-transformed cord blood cotinine levels, type of delivery, parity and infant sex, were included in the adjusted model. Because gestational age is considered to be the major influential factor for birth outcomes, gestational age was added to the adjusted model for birth outcomes for birth weight, birth length, head circumference, Ponderal index and low birth weight. Finally, we categorized PFOS levels into quartiles  and set the lowest level as a reference. The dose-response relationship between PFOS levels and birth outcomes was assessed using the same adjusted model. In addition, regression diagnosis was performed to identify influential points using Cook’s distance. Because the estimate was similar when these points were excluded from the analysis, only the results of all participants are presented. Statistical analyses were performed using SAS version 9.1 . All of the tests were two-sided, and statistical significance was accepted for There were 429 mother-infant pairs in total, and the geometric mean (standard deviation) levels were 1.84(2.23), 5.94(1.95), 2.36(4.74), and 10.26 (3.07) ng/mL for PFOA, PFOS, PFNA, and PFUA, respectively . Regardi3 for Ponderal index.β  = −0.37  for gestational age, −110.2  for birth weight and −0.25  for head circumference]. The β coefficients of LnPFOA for birth outcomes in both crude and adjusted models were mostly negative, except for gestational age, and did not reach statistical significance. A non-significant inverse association was also observed between LnPFUA and birth outcomes, except for birth length. For LnPFNA, β coefficients were mostly positive, except for Ponderal index, in both the crude and adjusted models. Significance was observed for birth length [per ln unit: β (95% CI) = 0.16 ] and Ponderal index [per ln unit: β (95% CI) = −0.02 ].The associations between PFCs levels in cord blood plasma and birth outcomes are displayed in P for trend was noted in gestational age, birth weight, head circumference and preterm birth. Among other birth outcomes, such as birth length, Ponderal index, small for gestational age and low birth weight, the effect of PFOS levels was the greatest in the highest exposure group compared with other exposure groups.The dose-response relationship between PFOS exposure and birth outcomes is presented in the figures. The PFOS levels were divided into quartile, and This study showed that PFOS levels in cord blood plasma are negatively associated with gestational age, birth weight, head circumference, preterm birth, and small for gestational age. After classifying the PFOS levels into quartiles, a dose-response relation was still observed among most of these birth outcomes. Among PFCs with chain lengths longer than 8 carbons, PFNA and PFUA were commonly detectable in this study population. However, we did not find a convincing association between birth outcomes and prenatal exposure to PFOA, PFNA or PFUA.in utero PFOS exposure can lead to increased fetal mortality and decreased body size 5) for decreased gestational length and birth weight effect was estimated to be 0.31 mg/kg/day and 0.39 mg/kg/day, respectively Animal studies in rodents have shown that in utero PFCs exposure and birth outcomes in humans is unclear The relationship between Our study results are similar to those of a Japanese study in utero PFNA exposure on birth weight Few studies have addressed the developmental toxicities of PFNA and PFUA. These two entities are PFCs with 9 and 11 carbon chains, respectively. According to the reported literature, PFCs with longer carbon chains exhibit slower urinary elimination and increased peroxisomal β-oxidase activity and accumulation in the mouse liver The levels of PFOA and PFOS in the present study differed from literature values . The stuIn the present study, several maternal and infant characteristics were found to be associated with levels of PFCs. Consistent with previous reports, cord blood PFOS and PFOA levels were relatively unaffected by maternal age or prepregnancy BMI Maternal smoking and exposure to ETS are well-known risk factors for adverse birth outcomes The strength of this study is its prospective cohort design, which minimizes recall bias, and the extraction of growth measurements from reliable medical records. Furthermore, the impacts of four PFCs, including products with a longer perfluoroalkyl chain, were investigated. To our knowledge, this is the first report on the association between prenatal PFUA exposure and birth outcomes. However, this study has several potential limitations. First, the sample size was not large enough to form conclusions on the impacts of PFCs on birth outcomes with low prevalence rates, such as low birth weight or small for gestational age. Second, a lack of information concerning maternal diet habits could further limit the exploration of exposure sources, but would not alter the impact of prenatal PFOS exposure on birth outcomes.In summary, higher PFOS levels in cord blood plasma were associated with adverse birth outcomes in a birth cohort in Taiwan. Longitudinal follow-up of the present study population could help clarify the long-term impact of PFCs on growth and the health effects of background exposure levels. Although the association between prenatal PFNA or PFUA and birth outcomes was not proven to be significant, the high detection rate and concentration of these two chemicals in cord blood plasma suggest human exposure, and the possibility of other health effects was not examined in this study.Table S1Summary of previous studies of prenatal perfluorooctyl sulfonate (PFOS) exposure and birth outcomes among the general populations.(DOCX)Click here for additional data file.Table S2Summary of previous studies of prenatal perfluorooctanoic acid (PFOA) exposure and birth outcomes among the general populations.(DOCX)Click here for additional data file.


Ethnic groups differ significantly in adult physique and birth weight. We aimed to improve understanding of maternal versus paternal contributions to ethnic differences in birth weight, by comparing the offspring of same-ethnic versus mixed-ethnic unions amongst Europeans and South Asian Indians in the UK.We used data from the UK Office for National Statistics Longitudinal Study (LS) and the Chelsea and Westminster Hospital (CWH), London. In the combined sample at all gestational ages, average birth weight of offspring with two European parents was significantly greater than that of offspring with two Indian parents [Δ = 344  g]. Compared to offspring of European mothers, the offspring of Indian mothers had lower birth weight, whether the father was European [Δ = −152  g] or Indian [Δ = −254  g]. After adjustment for various confounding factors, average birth weight of offspring with European father and Indian mother was greater than that of offspring with two Indian parents . Average birth weight of offspring with Indian father and European mother was significantly less than that of offspring with two European parents .Birth weight of offspring with mixed-ethnic parentage was intermediate between that of offspring with two European or two Indian parents, demonstrating a paternal as well as a maternal contribution to ethnic differences in fetal growth. This can be interpreted as demonstrating paternal modulation of maternal investment in offspring. We suggest long-term nutritional experience over generations may drive such ethnic differences through parental co-adaptation. Numerous studies have demonstrated substantial differences in stature, physique and adiposity between Europeans and South Asians. In adulthood, South Asians tend to have lower stature and fat-free mass than Europeans, and to be proportionally more adipose The causes of such ethnic differences in early growth and body composition remain poorly understood. Within populations, variability in adult stature is considered to have a strong genetic component. Twin studies of Europeans have suggested heritability values approaching 90% A recent multi-centre study in populations of high socio-economic status showed negligible ethnic variability in growth rate during fetal life and infancy Environmental factors are therefore an alternative contributing factor to ethnic differences in early growth and subsequent physique. Such effects may be exogenous  or endogenous . For some outcomes such as childhood intelligence quotient, ethnic differences disappear if adjusted for indices of poverty Parental contributions to fetal growth are complex, in that the mother provides the uterine environment, while both parents contribute to the fetal genome. One of the first experiments to attempt to disentangle parental genetic from non-genetic contributions to variability in size at birth involved the crossbreeding of Shire horses and Shetland ponies, two strains differing substantially in adult body size. Mating large Shire females with small Shetland males produced offspring larger than those from pure Shetland crosses, but smaller than those from Shire crosses, while crossing Shetland females with Shire males produced offspring no heavier than those of pure Shetland crosses Early studies of birth weight variability in humans likewise highlighted the importance of maternal influence on offspring growth. A study of Japanese families found that the birth weight correlation between half-siblings with the same mother (r = 0.58) was substantially greater than that between half-siblings with the same father (r = 0.10) in utero growth constraint is transmitted in a non-Mendelian fashion through the maternal line, a finding that has received some support from animal studies Building on the first study of birth weight correlations across generations Subsequent studies, however, have demonstrated independent associations of both parents' birth weights with that of the offspring, indicating moderation of maternal constraint by paternal phenotype. For example, in a study of ∼70,000 father-mother-child trios from Norway, birth weight correlations were 0.226 for mother-child and 0.126 for father-child Our understanding of the contributions of the two parents to fetal growth variability therefore remains incomplete, with both inconsistent evidence and contradictory interpretations. Furthermore, the majority of published human studies have explored the parental contributions to offspring birth weight within populations.To improve understanding of the difference in birth weight between Europeans and south Asians in the UK Taking advantage of the increasing prevalence in the UK of partnerships between people of Indian and European ancestry, we examined data obtained from the Office for National Statistics Longitudinal Study (LS) or routinely collected from the Chelsea and Westminster Hospital (CWH), West London, where parentage could be classified either as European-European, Indian-Indian, or inter-ethnic unions. Subjects were neonates whose parents described themselves as Indian, or white (referred to here as European), and the subject's inferred ethnicity was the main exposure. Individuals were excluded if either parent described themselves as having mixed ethnicity. Stillbirths and multiple pregnancies were also excluded.All data were analyzed anonymously. Written consent for the use of the CWH data for research was not taken because at the time the data were collected, it was not intended to use it for research. Subsequently, use of the CWH data for these analyses was approved by Riverside Research Ethics Committee. Ethical approval for the LS was originally given by the Patient Information Advisory Group . Our analysis of LS data, using non-identifiable information, did not require ethical approval. The Office for National Statistics board cleared our analyses for publication.The Longitudinal Study (LS) links data from household census returns with routinely recorded vital events data for a quasi-random, one percent sample of the population of England and Wales The Chelsea and Westminster Hospital (CWH) in West London is part of the National Health Service and serves a relatively affluent population with high ethnic diversity. Its high quality maternity database is frequently used for research purposes. Data are routinely collected and entered into the database, mainly by midwives. At antenatal booking, information on the self-described ethnicity of mother and partner has been collected, although mothers were not asked directly about the paternity of their child. Mother's height and weight were collected at booking, based on self-reports or measured if women did not know. Duration of gestation was assessed by a clinician, using his/her best estimate based on date of last menstrual period or ultrasound scan, whichever seemed more reliable. Parity  was obtained from obstetric records. For these analyses we included all live singleton deliveries at the hospital between April 1998 and January 2004, where the mother and father were either Indian or white European. An area-level indicator of socio-economic position was obtained by linking the mothers' home postcode at the time of delivery to the corresponding electoral ward Index of Multiple Deprivation score. Parents' marital status was not entered into regression models because data were missing for 8.1% of subjects.The following categories were used in the LS data: maternal age: <25, 25–29, 30–34, 35+ years; number of previous live births within marriage (‘parity’): 0, 1, 2, 3+; father's Registrar General's occupational social class: I, II, III, IV, V, plus a residual category for ‘other or inadequately described’ occupations; mother's occupational social class in 6 categories again; housing tenure: owner-occupied vs. rented/on short lease; maternal education: obtained a post-18 years qualification vs. no such qualification. The following categories were used in the CWH data: mother's age at delivery: <32, 32–34, 34+ years; mother's parity: 0, 1, 2+ ; Index of Multiple Deprivation score in quintiles (quintiles defined within this population); subject's gestational age: 37–38, 39–40, 41 weeks; mother's height to the nearest cm in quintiles: <160, 160–164, 165–166, 167–171, 172+ cm; mother's weight at booking in quintiles: <56, 56–59, 60–63, 64–69, 70+ kg. Subjects without complete data on all covariates were excluded from the multiple regression analysis.We compared birth weight (continuous variable) between each of the four possible categories of union. The study design is illustrated in Univariate analyses were performed using one-way analysis of variance (ANOVA) and t-tests for continuous variables, while for categorical variables contingency tables were prepared using Pearson's chi-square test, using Stata 11 . Multiple linear regression was performed to adjust for potential confounders  which were entered as categorical variables. We used robust standard errors to take account of any clustering of birth weight within families.The specific impact of paternal ethnicity on birth weight is demonstrated for the LS and CWH samples in Our results demonstrate, as expected on the basis of previous research The lower birth weight of offspring of Indian compared to European mothers, whether the father was Indian or European, indicates that Indian mothers contribute substantially to the lower birth weights of Indian neonates. However, since Indian mothers produced a larger baby if the father was European rather than Indian, the magnitude of Indian maternal constraint appears not to be fixed, but to be moderated by paternal effects. In the CWH analyses, these effects were seen even after adjustment for maternal anthropometry, indicating that they are not attributable to differences in maternal size alone. Since European mothers produced a smaller baby if the father was Indian versus European, Indian fathers appear to exert an independent restraining effect on fetal growth, suggesting that they also contribute to the smaller average birth weight of Indian compared to European offspring.We have found only one other study in the literature addressing similar questions More generally, both of these human studies are also consistent with findings from non-human animal studies. Although such work has been widely interpreted as demonstrating the primary influence of maternal phenotype on fetal growth, careful appraisal of the available evidence suggests a more complex scenario. Following the seminal study of Walton and Hammond, a number of further studies were conducted in several animal species, cross-breeding between strains differing substantially in adult body size Our human data are consistent with these general trends, in showing that European fathers generate on average a promoting effect on birth weight of the offspring of Indian mothers, while Indian fathers generate on average a constraining effect on birth weight of the offspring of European mothers. Parallel to the logic laid out by Walton and Hammond However, the paternal effects of our two ethnic groups were also asymmetrical, with the average European ‘paternal promoting’ effect (+240 g) twice the magnitude of the average Indian ‘paternal restraining’ effect (−90 g). This asymmetry is difficult to interpret, as it might indicate a combination of Mendelian genetic effects, parent-of-origin genetic effects, and epigenetic effects reflecting environmental differences. For example, Indian mothers living with European fathers may have experienced different living conditions compared to their counterparts living with Indian fathers. Despite these challenges in interpretation, our data offer support for the proposition that a proportion of ethnic variability in birth weight is due to paternal effects.Our study has some limitations, notably the small sample sizes of the mixed-ethnic groups, and the inability to adjust fully for parental size and factors such as maternal smoking or pregnancy weight gain. We do not believe paternity uncertainty has adversely influenced our findings, as the frequency of uncertainty must typically be high to cancel out alternative interpretations in utero can usefully be considered from an evolutionary perspective. Trivers The different parental contributions to offspring growth Such tension makes possible the evolutionary co-adaptation of paternal demand to maternal supply In a more sophisticated approach, Haig developed Trivers' ideas by focusing on the contribution to fetal growth of imprinted genes, differentially expressed in the offspring according to paternal or maternal origin More compelling evidence for the physiological mechanisms of paternal influence on fetal growth come from endocrinological studies. The placenta is able to release hormones  directly into the maternal bloodstream th century th century BCE An explanation for this lower demand of Indian offspring may lie in the contrasting nutritional histories of European and Indian populations. Recent archaeological evidence indicates that stature in India has decreased substantially over the last 8000 years Under conditions of energy scarcity, larger offspring are predicted to place greater stress on the maternal energy budget and hence threaten both maternal survival, and that of their existing and potential future siblings The notion that adaptations to population energy stress may occur within the developmental niche of maternal physiology, and through the mechanism of parent-offspring dynamics, may shed new light on the way in which ecological pressures induce evolutionary change in our species. Because growth is canalized from late infancy onwards Our findings are also relevant to the lack of evidence of birth weight increases in south Asians  born in the UK, compared to those born in their country of origin


In 2005, it was estimated that hypertension affected 26.4% of the adult population worldwide. By 2025, it is predicted that it will affect about 60% of adults, a total of 1.56 billion. Both pre- and postnatal growth patterns have been associated with later blood pressure (BP), but in contrasting directions. These inconsistent associations of growth during different developmental periods merit elucidation. We tested a theoretical model treating birth weight as a marker of homeostatic metabolic capacity, and childhood height, lean mass and fat mass as independent indices of metabolic load. We predicted that decreased capacity and increased load would be independently associated with increased BP.Data from the ALSPAC cohort on growth from birth to 7 years, and body composition by dual-energy X-ray absorptiometry and BP at 9 years, were analysed (n = 6579). Data were expressed as standard deviation scores (SDS) or standardised regression residuals (SRR). BP was independently and positively associated with each of height, lean mass and fat mass. In a joint model systolic BP was positively associated with conditional weight velocity [males 0.40 (95%CI: 0.37–0.44) & females 0.44 (95%CI: 0.40–0.47) SDS/SRR], but not birth weight [0.00 (95%CI: −0.03–0.04) & 0.03 (95%CI: −0.01–0.07) SDS/SDS]. Adjusting for height, lean mass and fat mass, the association of systolic BP and conditional weight velocity attenuated [0.00(95%CI: −0.09–0.08) & −0.06(95%CI: −0.14–0.03) SDS/SRR], whereas that with birth weight became negative [−0.10 (95%CI: −0.14–0.06) & −0.09 (95%CI: −0.13–0.05) SDS/SDS]. Similar results were obtained for diastolic BP and pulse pressure.Consistent with our theoretical model, high metabolic load relative to metabolic capacity is associated with increased BP. Our data demonstrate the contribution of different growth and body composition components to BP variance, and clarify the developmental aetiology of hypertension. Birth weight and growth in early life have been associated with later blood pressure (BP) in numerous studies, but the details of such associations remain controversial Both birth weight and rapid infant growth have been associated with later obesity as measured by body mass index (BMI) Few studies have explored the detailed contribution of body composition to BP variance. One study showed that sex differences in adult BP disappeared when adjusted for LM How childhood BP is influenced by early growth patterns and the accretion of different tissue masses therefore remains unclear. This situation may be improved by incorporating a theoretical perspective attempting to clarify how growth during different developmental periods affects physiological parameters that regulate and challenge BP.The thrifty phenotype hypothesis of Hales and Barker proposed that the small baby adapts to poor nutritional supply in-utero by reducing investment in vital organs such as the pancreas and kidney Building on previous work in adults that demonstrated independent associations of birth weight and adult height or BMI, with adult BP www.bristol.ac.uk/alspac. Briefly, ALSPAC is a prospective cohort study, investigating the health and development of children, which enrolled 14,541 pregnant women residing in three districts in Bristol, England, with expected delivery dates from 1 April 1991 to 31 December 1992. Data was obtained using self-administered questionnaires, data extraction from medical notes, linkage to routine information systems and through research clinics attendance.We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC). A full description of the methods is reported elsewhere Ethical approval for the study was obtained from the ALSPAC Ethics and Law Committee and the Local Research Ethics Committees; written consent was obtained from all participants and their parents/guardians.The ALSPAC study included regular assessments from 7–15 years for the whole cohort, although the nature of data collected changed over time. In the current analysis we examined data from 6,621 singletons  with complete data obtained at 9 years for sex, weight, height, body composition and BP. For this group, weight and length/height data were also available at birth  and at 7 years .Anthropometric data were available from several sources. Birth weight was extracted from medical records. Birth length (crown-heel) was measured by ALSPAC staff who visited newborns soon after birth , using Harpenden Neonatometers . Gestational age was obtained from self-reported date of last menstrual period. At each further assessment, weight and height were measured with the child in light clothing, without shoes. Weight was measured to the nearest 0.1 kg using Tanita scales  and height to the nearest 1 mm using Harpenden stadiometers (Holtain Ltd). LM and FM were assessed by dual-energy X-ray absorptiometry . BP was measured with Dinamap 9301 Vital Signs Monitors  with correct cuff sizes. Two readings of systolic and diastolic BP were recorded, with the child at rest with arm supported, and the mean of each calculated.Previous work has shown that each of height, LM and FM may be positively associated with BP Previous evidence has shown that height is positively associated with both LM and FM, which in turn are positively associated Anthropometric data at birth, 7 and 9 years were converted to UK 1990 z-scores The above approach converted all data into a comparable format, equivalent to z-scores, making it easier to compare information across different traits with different magnitudes of variance. To simplify for the reader and aid interpretation, the terms ‘standardised residual’ and ‘z-score’ were used to differentiate between those derived based on our sample, and those based on published normative data, respectively.For each sex, we then used regression analysis to evaluate the contribution of the various body components  to variance in BP outcomes. We then evaluated the independent contributions of prenatal growth  and postnatal growth . Finally, pre- and postnatal growth data for either weight or length/height were added to the model including the components of current metabolic load.To understand the possible contributions of metabolic capacity and load to children considered to have higher BP, placing them at a higher risk of future cardiovascular disease Characteristics of interest of the sample taken at birth, 7 years, and 9 years are described in The contributions of the different body components to BP, by sex, are shown in A similar pattern was observed for systolic BP z-score, but with explanatory variables showing larger regression coefficients and explaining more of the model variance. In males, height z-score showed a positive association and explained ∼8% of systolic BP z-score variance (Model 1). Inclusion of Wr/H (Model 2) increased the explanatory power of the model to ∼19%. When LMr/H and FMr/LM were included in the model instead of Wr/H (Model 3) all three components of load independently contributed positively to systolic BP z-score variance, together explaining a similar amount of variance (∼19%) as in Model 2. Similar findings were observed for females.Likewise, in males and females, height z-score alone (Model 1) or height and Wr/H together (Model 2) independently contributed positively to PP z-score variance. Inclusion of LMr/H and FMr/LM in the model instead of Wr/H (Model 3) did not alter the explanatory power of the model, with all three components independently showing a positive association with PP z-score.The contributions of pre- and postnatal growth in weight to BP, alone and in conjunction with the different body components are presented in Table S1).In Model 2, for all BP components in both sexes, CWV showed positive associations, whereas birth weight z-score did not show an association. Early growth explained ∼4% of diastolic BP z-score variance in both sexes, ∼15 and ∼17% of the variance of systolic BP z-score for males and females, respectively, and ∼9 and ∼11% of the variance of PP z-score for males and females, respectively. In Model 3, a similar pattern was observed for all BP components. The association of CWV with any component of BP was attenuated to the null with inclusion of current measures of metabolic load in both sexes, whereas an inverse association for birth weight z-score appeared. A similar pattern of results was observed when using length at birth z-score and conditional height velocity . For Model 2, an increase in CWV increased the odds of higher BP while birth weight z-score did not alter the risk. In Model 3 an increase in all three current components of metabolic load increased the odds for higher BP while an increase in birth weight z-score reduced the odds. In Model 3, the odds for higher BP for an increase of CWV were attenuated to the null.Table S2). The only difference was that birth length z-score did not alter the odds for higher BP in any model in which it was included.When including birth length z-score and CHV in the modelling, similar patterns of results were observed  to BP variance or the odds for higher BP, only postnatal growth contributed; however, after holding current metabolic load constant, the contribution of postnatal growth attenuated and an inverse association of birth weight became apparent. This indicates first that for a given metabolic load, a diminished metabolic capacity increases BP, and second that the association of postnatal growth on BP may be attributable to increased metabolic load.Previously, most emphasis has been directed to the positive association of BMI or FM with BP The association between early growth patterns and later BP is complex, and improved conceptual models may help resolve seemingly contradictory findings. The known negative association between birth weight and BP is considered by some the most consistent evidence supporting the thrifty phenotype hypothesis The association between adult height and cardiovascular disease risk remains uncertain, with both tall and short individuals proposed to have greater risk than those of intermediate height The concepts of metabolic capacity and load help to understand how growth during different periods influences BP. In relation to metabolic load, the associations of height, LM and FM with BP may derive from several physiological mechanisms. FM may contribute to BP either through hormonal mechanisms, such as perturbations of the renin-angiotensin-aldosterone system or leptin regulation The physiological component of metabolic capacity most relevant to BP is likely to be nephron number, which has a tight positive association with birth weight over the majority of the birth weight range In addition to our main analyses, we further investigated the odds ratio of components of metabolic capacity and load for higher BP. Whilst higher BP in children may derive from white coat effect as well as somatic properties, our data indicate that smaller birth size and larger size in childhood both contribute to the likelihood of having higher BP. Our results indicate a modest protective effect of birth weight, but substantial adverse effects of all three components of metabolic load. Thus, in a group characterised by higher BP in childhood, who are at increased risk of high BP in adulthood The comparable contributions of metabolic load and postnatal growth to BP were different for diastolic compared to systolic BP or PP. First, metabolic load components showed greater regression coefficients and odds of higher BP for systolic BP and PP than for diastolic BP in both sexes. Second, the association between LM or height and diastolic BP was not consistent between the sexes, in contrast to systolic BP and PP. Our results indicate the possibility of independent pathways by which the different body components and postnatal growth impact on diastolic BP and PP.The strengths of this analysis include the well characterised prospective cohort, the large sample size, the objective measures of body composition, and the use of the conceptual model of capacity and load. The limitations include some loss to follow-up, although this is unlikely to have adversely influenced our findings, limitations in the accuracy of DXA in association with fatness Our findings are relevant to public health policies aimed at reducing the childhood antecedents of adult hypertension. Others have argued that rapid weight gain at any point in childhood is associated with greater BP In summary, our study used a conceptual model to help understand associations of early growth with later BP. Three different components of childhood metabolic load were each independently associated with BP and the odds of higher BP. The association between postnatal growth and BP could be attributed to these elements of metabolic load. Holding metabolic load constant, BP and the risk of higher BP were elevated in those with lower birth weight, representing reduced metabolic capacity.Table S1Linear regression models for the prediction of systolic and diastolic blood pressure z-score and conditional pulse pressure by height, weight, lean and fat mass, birth length and conditional height velocity residual.(DOC)Click here for additional data file.Table S2Logistic regression for the odds of higher blood pressure.(DOC)Click here for additional data file.


To evaluate, retrospectively, the roles of endogenous and exogenous luteinising hormone (LH) activity on live birth rate in ovulation induction cycles.Associations between LH activity at baseline, end of stimulation and live birth rate were analysed in relation to patient characteristics, baseline and end of stimulation variables in WHO group II anovulatory women (n=155) stimulated with recombinant follicle-stimulating hormone (rFSH) or highly purified human menopausal gonadotrophin (HP-hMG). HP-hMG provides FSH and exogenous LH activity mainly in the form of human chorionic gonadotrophin (hCG).Serum LH concentrations at baseline or end of stimulation were not predictive of live birth rate in the rFSH group (n=79) or HP-hMG group (n=76). Serum hCG concentration at end of stimulation was a significant positive predictor in HP-hMG-treated women. Other variables were not independently predictive of live birth in either of the groups, except for a negative association between serum FSH concentrations at the start of stimulation and live birth in the rFSH-treated group.Endogenous LH concentrations are not predictive of live birth in anovulatory WHO group II patients undergoing ovulation induction with rFSH or HP-hMG. On the other hand, exogenous hCG activity during HP-hMG stimulation is positively associated with treatment outcome. WHO group II anovulatory infertility is the most frequent anovulatory disorder, with the majority of such patients being diagnosed with polycystic ovary syndrome (PCOS) . ManagemDespite a normal follicle stimulating hormone (FSH) concentration, an elevated luteinising hormone (LH) concentration is not unusual in PCOS patients . Both thA number of studies are available on the impact of endogenous LH on fertility as well as treatment outcome during stimulated cycles in anovulatory patients. In women with regular spontaneous menstrual cycles, the endogenous LH concentration has been found to be higher in women with primary or secondary infertility than in fertile women . The assprior to treatment has been associated with a high probability of conceiving (during the follicular phase of CC treatment have been associated with poor treatment outcome (during gonadotrophin-releasing hormone (GnRH) pulsatile treatment and failure to conceive has been reported in PCOS patients  preparations which contain both FSH and LH activity . HoweverThe major aim of the present retrospective study was to evaluate the roles of endogenous and exogenous LH activity on live birth rate in WHO group II anovulatory women stimulated with rFSH or highly purified menotrophins (HP-hMG), which provide FSH and exogenous LH activity mainly in the form of human chorionic gonadotrophin (hCG). Thus, serum concentrations of LH represent mainly the endogenous LH activity in both groups, and serum hCG represents the exogenous LH activity, which is present only in the HP-hMG group. Serum LH and hCG were compared between those women who achieved a live birth and those who did not, for both treatment regimens. To evaluate potential confounding predictors of live birth, we subsequently performed a full logistic regression analysis of the associations between live birth rate and an extensive range of patient characteristics, as well as endocrinological variables at baseline and end of stimulation.per se (i.e. ruling out the no live birth response due to lack of ovulation), only the women who ovulated after stimulation were included in the study cohort (n= 155). Main inclusion criteria were chronic anovulation , failure to ovulate with CC doses of at least 100 mg/day for at least 5 days or failure to conceive after three cycles of ovulation induction with CC, an age of at least 18 but not more than 39 years, a body mass index (BMI) of 19-35 kg/m2, and early follicular serum FSH concentrations between 1 and 12 IU/1. The study was carried out in accordance with the Declaration of Helsinki on good clinical practice, and ethical committee approval was obtained in all participating centres. Written informed consent was obtained from all trial subjects.This retrospective study was based on 184 women with normogonadotropic anovulatory infertility (WHO Group II) who participated in a prospective randomised controlled multicentre trial, which had ovulation rate as the primary outcome measure after ovulation induction with different gonadotrophin preparations [HP-hMG  and rFSH ] using a low-dose step-up protocol . HP-hMG Stimulation treatment was started 2-5 days after a spontaneous or progesterone-induced menstrual bleed. The starting dose of gonadotrophin was 75 IU daily, which was maintained for 7 days. After the first 7 days, the dose was either maintained or increased by 37.5 IU increments according to individual responses. All subjects were maintained on their specific dose concentration for at least 7 days. The maximum permitted daily dose was 225 IU, and the women were treated with the gonadotrophin for a maximum of 6 weeks. A single dose of 5,000 IU of hCG  was given to trigger ovulation when one follicle of > 17 mm or two to three follicles of > 15 mm were observed by vaginal ultrasound. Any medication for luteal support (e.g. progesterone or hCG) was prohibited.Blood samples were taken on stimulation day 1 (prior to the start dosing with gonadotrohins) and at the end of stimulation (at least 8h after the last gonadotrophin dose). Serum was analysed for endocrine variables by a central laboratory using an electrochemiluminescence immunoassay ), a radioimmunoassay , a chemoluminescence assay (insulin), and an enzymatic method (glucose). The lower detection limits of the validated analytical methods were as follows: LH 0.10 IU/1, FSH 0.10 IU/1, hCG 0.10 IU/1, total testosterone 0.17 nmol/1, prolactin 0.3  in the mid-luteal phase (6-9 days after hCG). Clinical pregnancy was defined as a transvaginal ultrasound showing at least one intrauterine gestation sac with foetal heart beat 7-9 weeks after hCG administration. Live birth was defined as a cycle that resulted in at least one live born neonate, regardless of the number of other neonates (live born or still born).Student's t-test was used for comparison of continuous variables between those women who did, and those who did not, achieve a live birth. The demographic and pre-stimulation variables as well as the variables obtained at end of ovarian stimulation for each treatment group were included in a primary univariate logistic regression analysis with the dependent variable live birth. The predictive value of each variable was summarised as an odds ratio with 95% confidence interval. The hCG values were multiplied by 10 to have a more interpretable OR estimate. All variables with a p-value <0.05 in the univariate regression analysis were then included in a secondary multivariate regression analysis for each treatment group. The multivariate model was reduced stepwise and the variables that were significant predictors of live birth at the <5% level are presented. Model fit was checked by the Hosmer and Lemeshow Goodness-of-Fit test. Tests for differences between variables in subgroups stratified into the 25th and 75th percentiles of exogenous serum hCG concentrations at end of stimulation were performed using the Kruskal-Wallis test for continuous data and the Chi-square test for categorical data.Seventeen women in the rFSH group had a positive clinical pregnancy test and 16 of them achieved a live birth (14 singletons and 2 multiples). In the HP-hMG group, 14 women had a positive clinical pregnancy test and 13 of them achieved a live birth . The endogenous LH concentrations prior to treatment did not differ significantly between the live birth and non-live birth subgroups in rFSH- or HP-hMG-treated women . NeitherIn the group of women who were stimulated with rFSH, the univariate logistic regression analysis of the associations between demographic and prestimulation variables as well as the variables obtained at end of ovarian stimulation and live birth showed that there was no significant association between the endogenous LH concentration and live birth rate; neither at baseline  nor at end of stimulation  and exogenous hCG at end of stimulation . Similar to the rFSH group, neither the endogenous LH concentration at start of stimulation  nor the LH concentration at end of stimulation  was significantly associated with live birth rate. Furthermore, there was no correlation (p = 0.340) between the concentrations of LH and hCG at end of stimulation in the group of women stimulated with HP-hMG (data not shown). There was a trend towards an association between live birth rate and antral follicle count , while no other demographic, baseline, clinical, sono-graphic or endocrine variable was associated with live birth rate. When eliminating the non-significant variables stepwise in a multivariate logistic regression analysis, the exogenous hCG concentration at the end of stimulation was the only significant predictor of live birth rate at the 5% level in the HP-hMG group. Model fit was checked by the Hosmer and Lemeshow Goodness-of-Fit test, which gave an acceptable fit (p = 0.518).The HP-hMG treated women were stratified into the 25th and 75th percentiles (P) of exogenous serum hCG concentrations at end of stimulation, resulting in subgroups of <P25, >P25-P75, and >P75. The live birth rate was lowest (6%) in the <P25 quartile and highest (35%) in the >P75 quartile . No signThe present study did not find a significant association between serum concentrations of LH at baseline and live birth rate, neither in the rFSH group nor in the HP-hMG group. In line with this observation, the endogenous LH levels were similar in women who achieved a live birth and in those who did not. The lack of association between the LH level and outcome in the current study is in agreement with the results of a retrospective study in women with normogonadotropic anovulatory infertility resistant to CC-therapy treated with FSH activity gonadotrophin preparations , but in The present study shows for the first time that increased serum concentrations of exogenous hCG at the end of stimulation were associated with higher live birth rates in normogonadotropic anovulatory infertile women treated with HP-hMG. Actually, among all the variables obtained at baseline or end of stimulation, the hCG concentration was the only variable predictive of treatment outcome in the multivariate logistic regression analysis. This is an interesting, novel finding in a PCOS population with already normal or high endogenous LH concentrations prior to starting the ovulation induction treatment. In this context, it is important to note that any interpretation of the relation between endogenous LH concentrations and outcome in HP-hMG-treated women is confounded by the fact that there is an intervention with exogenous hCG, supplementing additional LH activity.The higher serum hCG concentrations (as well as FSH concentrations) in patients in the highest quartile group at the end of stimulation could be explained by their higher final daily dose of HP-hMG. These patients had a longer duration of stimulation in order to achieve the desired follicular response, but also had significantly higher estradiol levels than the patients in the other quartiles, despite an apparently comparable degree of follicular response. The finding of higher estradiol levels despite similar follicular response could reflect the effect of higher hCG levels on follicular differentiation. Also, the number of antral follicles was different between the percentile subgroups, but was not higher for the >75th percentile. A trend towards a lower BMI in the highest quartile group is in line with a previous report , which sin vivo of hCG may be greater than could actually be extrapolated from immunoassay concentrations  cycles or oocyte donors, which usually exclude patients with PCOS .In summary, in anovulatory patients with normal or elevated baseline endogenous LH concentrations undergoing ovulation induction with gonadotrophins, the LH concentration at baseline or end of stimulation is not significantly associated with live birth rate. The exogenous LH activity, provided mainly in the form of hCG by using the HP-hMG gonadotrophin preparation, does not appear to be detrimental to live birth rates. Patients with higher serum hCG levels at the end of stimulation actually had the higher live birth rates in this treatment regimen.


Hookworm infections are significant public health issues in South-East Asia. In women of reproductive age, chronic hookworm infections cause iron deficiency anaemia, which, upon pregnancy, can lead to intrauterine growth restriction and low birth weight. Low birth weight is an important risk factor for neonatal and infant mortality and morbidity.We investigated the association between neonatal birth weight and a 4-monthly deworming and weekly iron-folic acid supplementation program given to women of reproductive age in north-west Vietnam. The program was made available to all women of reproductive age  in two districts in Yen Bai Province for 20 months prior to commencement of birth weight data collection. Data were obtained for births at the district hospitals of the two intervention districts as well as from two control districts where women did not have access to the intervention, but had similar maternal and child health indicators and socio-economic backgrounds. The primary outcome was low birth weight.The birth weights of 463 infants born in district hospitals in the intervention (168) and control districts (295) were recorded. Twenty-six months after the program was started, the prevalence of low birth weight was 3% in intervention districts compared to 7.4% in control districts . The mean birth weight was 124 g  greater in the intervention districts compared to control districts.The findings of this study suggest that providing women with regular deworming and weekly iron-folic acid supplements before pregnancy is associated with a reduced prevalence of low birth weight in rural Vietnam. The impact of this health system-integrated intervention on birth outcomes should be further evaluated through a more extensive randomised-controlled trial. Low birth weight is an important risk factor for neonatal and infant morbidity and mortality and may impact on growth and development. Maternal iron deficiency anaemia contributes to intrauterine growth restriction and low birth weight. Hookworm infections and an iron-depleted diet may lead to iron deficiency anaemia, and both are common in many developing countries. A pilot program of deworming and weekly iron-folic acid supplementation for non-pregnant women aiming to prevent iron deficiency was implemented in northern Vietnam. We compared the birth weight of babies born to women who had had access to the intervention to babies born in districts where the intervention had not been implemented. The mean birth weight of the intervention districts' babies was 124 g more than the control districts' babies; the prevalence of low birth weight was also reduced. These results suggest that providing women with deworming and weekly iron-folic acid supplements before pregnancy is associated with increased birth weight in rural Vietnam. This intervention was provided as a health system integrated program which could be replicated in other at-risk rural areas. If so it could increase the impact of prenatal and antenatal programs, improving the health of both women and newborns. Low birth weight is widely recognised as a risk factor for neonatal mortality and morbidity, as well as reduced cognitive function and the development of chronic diseases in later life It is estimated that more than one third of women in the world are anaemic Previous studies have reported benefits to maternal and infant health through antenatal supplementation with iron-folic acid supplements and multiple micronutrients In Vietnam, the prevalence of anaemia has previously been reportedly as high as 65% in pregnant and 54% in non-pregnant women, and in 2003 it was estimated that 21.8 million people had hookworm infections We hypothesized that the consequent improvement in women's nutritional status would translate to improvements in birth weight of their babies compared to babies born to women in adjacent districts where the intervention was not available.The project was approved by the Human Research Ethics Committee of the National Institute of Malariology, Parasitology and Entomology , the Walter and Eliza Hall Institute of Medical Research  and Melbourne Health . The birth weight survey was locally approved by the Yen Bai Ministry of Health. Extensive consultation was undertaken between the project team and community leaders, as well as liaison with village, district and provincial health staff. Village health workers provided participants with information regarding the intervention and signed informed consent was documented. For the birth weight survey, the mother's informed consent was obtained verbally before data collection, as approved by the Yen Bai Ministry of Health Research Committee and in accordance with the Vietnamese Ministry of Health protocols for surveys. Oral consent was documented by the presence of a witness.2) 4)/folic acid (60/0.4 mg) and 4-monthly albendazole (400 mg) to women was introduced. A detailed account of the protocol has been previously reported The pilot intervention was conducted in Tran Yen and Yen Binh districts, with Luc Yen and Nghia Lo as control districts, all in Yen Bai province, a remote, mountainous province in Vietnam with low population density . The digital scales were checked before each measurement against standard weights, and regularly calibrated. Weight was measured within 1 hour after birth to the nearest 10 grams; each measurement was performed twice and the mean value reported. Low birth weight was defined as <2500 g All analyses were conducted on an intention-to-treat basis. Multiple gestations, still born babies and those with malformations did not differ between trial and intervention districts  and were excluded from the analysis. Socio-economic background and baseline characteristics of pregnant women were compared across the study and control group to assess comparability.The primary outcome was low birth weight. The secondary outcome was mean birth weight. A crude sample size calculation performed prior to initiation of the study indicated that approximately 240 individuals would be required in each group in order to detect, with 80% power, a significant difference in % low birth weight at significance level 0.95 and assuming that 2% and 8% of the pregnancies in the treated and control groups, respectively, would exhibit low birth weight. Odds ratios for low birth weight were estimated using a multiple logistic regression model, adjusting for maternal characteristics and socioeconomic and educational background. Mean birth weight differences were compared using a linear regression model. All models were implemented via generalized estimated equations methodology to account for the correlation due to within-district clustering Atlantic Philanthropy Inc. sponsored the study and had no role in the study design, data collection, data analysis, data interpretation, or writing of the report.Four hundred sixty-three infants were born in the 4 district hospitals during the period of observation (January 2008–Jun 2008), 168 in intervention districts  and 295  in control districts.Demographic data for the participants by study arm including maternal age at delivery, parity and socio-economic and educational background are shown in The prevalence of low birth weight was 3% and 7.4% in the intervention and control districts respectively . This eqMean birth weight was 124 g higher in intervention districts  . Mean biWe present here results that show that the prevalence of low birth weight in infants born to mothers in rural Vietnam who had access to a pre-pregnancy program of 4-monthly albendazole treatment and weekly iron-folic acid was 3.0% compared to 7.4% for those born in neighbouring districts where women did not have access to this intervention. The latter is comparable to the Vietnam national average for low birth weight of 7.0% While there are numerous studies assessing the benefits of ante-natal iron supplementation for pregnant women, birth outcome and infant health Our study has limitations. The study design is not that of a randomized controlled trial, which would allow a more conclusive interpretation of the results. We have tried to adjust for potential confounders but other variables may exist that would bias the results. However, our study was conducted during the implementation of a large scale anaemia and iron deficiency prevention program, and therefore provides information about the impact of the intervention when implemented under field conditions through routine health services.We are not sure about the exact supplements women took during pregnancy and with what frequency. When questioned, women were unsure of the number and source of free iron-folic acid supplements provided by health workers during pregnancy. Those who bought antenatal nutrition supplements privately did so on the recommendation of a doctor or relation/friend and again were unable to clearly state what the supplements were or how much iron they contained. We therefore cannot exclude a possible bias in the results due to differences in antenatal iron supplementation patterns between the intervention and control districts.The intervention in Tran Yen/Yen Binh did not have separate arms for iron-folic acid or deworming alone so the relative contribution of each cannot be ascertained. A previous pregnancy supplementation and deworming study suggested that haematinics and anthelminthics had an additive effect on stabilizing haemoglobin during pregnancy when given to 125 Sierra Leone women, with haematinics having the greater effect Another limitation was that we were not able to sample the entire pool of deliveries of mothers from intervention and control districts, as the cost and logistics in such a remote area were beyond the resources available to this study. District hospitals collect about a third of routine deliveries; although this is not a fully comprehensive sample, we believe it is representative enough across the study districts. Furthermore, if selection bias did exist, we assume it would be similar in intervention vs control districts.It is also important to acknowledge that this intervention would increase the workload of community health workers, which is currently a topic of debate in the international development community. This may challenge the long term sustainability of the implementation and needs to be taken into consideration by health authorities in planning for the intervention.The data presented here is the result of one of few studies of the impact of pre-pregnancy iron-folic acid supplementation and deworming for non-pregnant women on infant birth weight. Whilst it has been recently suggested that there is a need for stronger, more robust data to support long-term intermittent iron-folic acid supplementation in women of reproductive age The results of our study suggest that the pre-pregnancy combination of deworming and weekly iron-folic acid supplementation for women of reproductive age in northern Vietnam is associated with a reduced incidence of low birth weight and higher mean birth weight. Such a program could potentially represent a high-impact and easily implementable intervention to apply in settings with a high prevalence of hookworm infection and anaemia, for the health of both women and newborns.


Increased low-density lipoprotein cholesterol (LDL) concentration is associated with increased risk of coronary heart disease (CHD) but a substantial risk of cardiovascular disease often remains after LDL concentrations have been treated to target. Apolipoprotein B (apo B) is the major apolipoprotein contained within atherogenic lipoproteins such as LDL, and apo B is a more reliable indicator of cardiovascular risk than LDL concentration.Our aim was to develop a formula for calculating apo B using lipid biochemistry measurements that are commonly available in clinical practice. We examined the clinical and laboratory data from 73,047 Koreans who underwent a medical health check that included apolipoprotein B concentration. The study sample was randomly divided into a training set for prediction model building and a validation set of equal size. Multivariable linear regression analysis was used to develop a prediction model equation for estimating apo B and to validate the developed model.The best results for estimating apo B were derived from an equation utilising LDL and triglyceride (TG) concentrations [ApoB = −33.12 + 0.675*LDL + 11.95*ln(tg)]. This equation predicted the apo B result with a concordance correlation coefficient (CCC and 95%CIs) = 0.936 ).Our equation for predicting apo B concentrations from routine analytical lipid biochemistry provides a simple method for obtaining precise information about an important cardiovascular risk marker. The association between increased concentrations of low-density lipoprotein cholesterol (LDL) and increased rates of premature coronary heart disease has been clearly demonstrated -8. CurreApolipoprotein B100 (apoB) is the structural protein for atherogenic lipoproteins and facilitates the transporting of lipid from the liver to peripheral tissues ,21-23. AApo B100 can be measured by commercial immunoassay  but assaA total of 73,047 apparently healthy subjects were recruited for the study. The mean age was 41.73 ± 8.4 years, . Subjects participated in a routine health check-up program that was held at the Health Promotion Center of Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea in 2008. The medical health checkup program was developed to improve the health of employees. Most subjects were employees, or family members, from various industrial companies across the country. The cost of medical examinations was predominantly paid for by the employers, and most subjects underwent a health check annually or biannually. The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki as reflected by a priori approval from our institution’s Human Research Committee.The health check consisted of a full medical history and comprehensive blood test evaluation. Participants’ height and weight were measured barefoot and in light clothing. BMI was calculated as weight in kilograms divided by height in meters squared. Laboratory examinations were obtained after an overnight fast. An enzymatic calorimetric test was used to measure TC and TG concentrations. The selective inhibition method was used to measure HDLc, and a homogeneous enzymatic calorimetric method was used to measure the concentration of LDLc . Apo B100 and apoA1 concentrations were determined by rate nephelometry .Descriptive statistics for continuous variables are presented as means, standard deviations (SDs), medians and inter-quartile ranges . Categorical variable are presented as proportions (percentages).p-values < 0.05 were considered significant. Statistical analyses were performed using SAS 9.1.3  and R 2.13.2 .The study sample was randomly divided into a training set for prediction model building and a validation set of equal size. Multivariable linear regression analysis was used to develop a prediction model equation and to validate the developed model. Natural log transformation was used to normalize the distribution of HDLc, TG, age and BMI. Analysis of residuals was used to check assumptions for multivariable linear regression modeling. The accuracy of the prediction model equation was evaluated using concordance correlation coefficient (CCC) analysis (Lin (1989)) that allowed comparison between prediction modeling results and the direct biochemical measurement of apo B100. In all tests, 2) and apoB quartile, in order to examine whether the derived equation was appropriate for specific subpopulation.We conducted subgroup analyses by sex, glucose (7.0 mmol/l or 126 mg/dl), BMI  and ln(Age) produced a higher F –statistic than one that also included ln(BMI). However, since BMI added little to an equation that included just LDLc, and TG, we tested the equation ‘ApoB100 = −33.12 + 0.675*LDL + 11.95*ln(tg)’ in the validation data-set. In this data-set the CCC was 0.936(95% CI(0.935-0.937)).We developed equations for predicting apo B100 from the results of multivariable regression modeling and compared apo B100 concentrations obtained by direct measurement with apo B100 estimates from various prediction model formulae Table . An equa2) thresholds, and apo B100 quartiles ). We also tested the formula also in subjects with an atherogenic lipid profile, namely in those with a TG > 150 mg/dl + HDLc < 40/<50 mg/dl. In individuals with TG > 150 & HDLc < 50 , the CCC was 0.923(95% CI(0.917-0.929)). In individuals with TG > 150 & HDcL < 40 , the CCC was 0.932(95% CI(0.924-0.939)). We also calculated the performance of the proposed equation using estimated LDLc from Friedewald’s equation. The CCCs are 0.920(95% CI(0.919-0.922)) in the training data-set and 0.922(95% CI(0.920-0.924)) in the validation data-set.The CCC for obese individuals with a BMI > 28kg/mMeasurement of apo B100 concentrations helps cardiovascular risk prediction but unfortunately to date apo B100 assays are often not available because they are considered expensive and time consuming. Consequently, apo B100 measurements are not readily available to clinicians. From a very large cohort of subjects that are representative of a general Asian population, we have developed a very simple algorithm for estimating apo B100 concentration that utilizes only LDLc and fasting triglyceride concentrations. Although more complex equations fitted the data slightly better for predicting apo B100; the very simple algorithm did not compromise precision, compared with the more complex equations. We have also shown that the simple algorithm is valid in important sub groups of people that included obese subjects, subjects with increased plasma glucose concentrations and subjects with an atherogenic lipid profile. The derived formula is also appropriate if LDLc is estimated from Friedewald’s equation.nd and 3rd quartile. We reason that it is more important to fit the formula to the whole population and not to a specific subgroup within that population.The CCCs for apoB100 in Q2 and Q3 were lower than for the other two quartiles. To evaluate the reason for the lower CCC results in Q2 and Q3, we compared the characteristics of the relationship between apoB100 and LDLc in each quartile. In the total data set, the relationship between apoB100 and LDLc showed a clear positive linear relationship, whereas in Q2 and Q3, the relationship was not linear In Q2 and Q3 the data points were concentrated around the middle of the distribution, rather than being spread evenly along the regression line. Consequently, the scatter of data in these middle two quartiles did not fit the regression line as well as in Q1 and Q4. Thus, this finding may limit the usefulness of our formula in these middle two quartiles. However, our equation was developed for the whole population and not just for the subjects in the 2In conclusion, we have developed an algorithm in a large Asian population to derive an estimate of apoB100 concetnrations that utilizes only measurement of LDLc and triglyceride concentrations from a fasting plasma sample. We are unable to comment as to whether the algorithm is valid in a Western population.All authors have no relevant conflicts of interests.K-CS; study concept and design, acquisition of data; analysis and interpretation of data. D-SC; critical revision of the manuscript for important intellectual content. J-HK; critical revision of the manuscript for important intellectual content. SW; acquisition of data; analysis and interpretation of data. SK; acquisition of data; analysis and interpretation of data. CDB; critical revision of the manuscript for important intellectual content. All authors read and approved the final manuscript.


In a large set of twin pairs, we compared twins born after IVF to naturally conceived twins with respect to birth characteristics, growth, attainment of motor milestones, and emotional and behavioral problems. Twin families were registered with the Netherlands Twin Register. We included 1534 dizygotic (DZ) twins born after IVF, 5315 naturally conceived (NC) DZ twins, and 1504 control NC DZ twins who were matched to the IVF twins based on maternal age, maternal educational level, smoking during pregnancy, gestational age, and offspring sex. Data were obtained by longitudinal surveys sent to fathers, mothers, and teachers at ages 1, 2, 3, 7, 10, and 12 years. Results showed no differences in growth, in attainment of motor milestones, and in behavioral development between IVF and matched NC twins. It can be concluded that for nearly all aspects, development in IVF and NC children is similar. In the Netherlands, the number of children born after assisted reproductive technologies (ART) including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) is rapidly increasing. In 1996, 1 in 77 newborns was born after IVF or ICSI treatment and in 2005, this had increased to 1 in 43 [Previous research on perinatal and obstetric outcomes of twin pregnancies after assisted reproduction has produced mixed results. The comparison of the outcomes of IVF/ICSI twin pregnancies and NC twin pregnancies is complex because IVF/ICSI mothers are older than mothers of NC twins, are more often primiparous, and have a history of infertility problems, all factors that may negatively influence perinatal and obstetric outcomes . In addiIn recent years, a growing number of studies investigated the longer-term development in growth, health, and psychosocial development of IVF/ICSI children , 15, 16.Most research on IVF-related outcomes is done in singletons, and data on development of IVF twins are limited , 21. In Up until now the short- and long-term development of IVF/ICSI children has mainly been studied in singletons. Because a significant proportion of IVF pregnancies results in a twin pregnancy, it is important to examine whether there are differences in development between twins after fertility treatment and NC twins. Comparing IVF twins to control samples of singletons may introduce bias as twins are at higher risk than singletons for low birth weight, low gestational age, and developmental delays. In this study we compare the development of IVF twins to carefully matched control twins. We look at perinatal outcomes, growth, motor development, and behavior problems during childhood. Because the proportion of MZ twins is low following IVF/ICSI conception, only DZ twins were included. The IVF and the NC DZ twins were matched on birth cohort, maternal age and educational level, smoking behavior during pregnancy, and gestational age of the twins.The data on mode of conception and development measures in twins come from a longitudinal study designed to examine the genetic and environmental influences on the development of behavioral and emotional problems in twins from birth onwards. The twin families are volunteer members of the Netherlands Twin Register (NTR) maintained by the Department of Biological Psychology at VU University in Amsterdam –39. The Data on mode of conception, mode of delivery, age at birth, gestational age, birth weight, birth order, sex of twins, and smoking behavior of both parents during pregnancy come from survey-1 which is collected after parents register their twins (age < 1 years). Information on maternal educational level was obtained at age 3 of the twins (survey-3), and if missing, educational level was supplemented with information obtained at ages 7 (survey-7) or 10 (survey-10). N = 72 for the IVF/ICSI group; N = 3686 for the NC group). Information on zygosity of 808 same-sex twin pairs was based on blood group/DNA group polymorphisms. For the remaining same-sex twin pairs (N = 6998), zygosity was assessed using items about physical similarity and frequency of confusion of the twins by family and strangers [For 11708 twin pairs complete data on the variables used for matching were available . There were 9001 twin pairs who were born following natural conception, 1606 pairs born following IVF/ICSI (at least 288 pairs after ICSI), and 1101 pairs born after ovulation induction. For the analyses we excluded twin pairs conceived by ovulation induction and all MZ pairs .In the analyses, there were 1534 DZ IVF/ICSI twin pairs (1606 minus 72 MZ twin pairs); these are referred to as IVF twins throughout the paper. From a total of 5315 NC DZ twin pairs, a control group of NC DZ twin pairs was formed by matching for birth cohort, gestational age, age of mother at birth, smoking behavior during pregnancy, zygosity, and maternal educational level  no hormonal preparations, (2) oral contraceptives before getting pregnant, (3) ovulation induction, and (4) ovulation induction in combination with IVF. Endorsement of more than one answer was possible. In 2005, a 2-page survey with questions about familial twinning, fertility, and twin pregnancy was sent to all mothers of twins who were registered with the NTR . This suIn survey-2, mailed out when the twins were 2 years old, the mother was asked to report the age at which certain motor milestones were reached (turning over from back to belly (turning), sitting without support (sitting), crawling on hands and knees (crawling), standing without support (standing) and walking without support ) , 44. WitAt age 3, externalizing and internalizing behavior problems were assessed using the CBCL/2-3 . Both paBehavior problems were measured at ages of 7, 10, and 12 years using the CBCL/4-18 . The scaAfter consent was obtained from parents, teachers of twins were asked to fill in a questionnaire about the twins' behavioral problems. Teachers were required to have known the children for at least 3 months. At the ages of 7, 10, and 12 years, teachers rated behavioral problems using the Teacher's Report Form (TRF ). The TRMaternal education level was measured on a 13-point scale, ranging from primary education to postdoctoral education. Educational level was classified into three categories .Mothers of twin pairs were asked to report offspring height and weight in the surveys at ages 1, 2, 3, 7, 10, and 12 years. Data were converted to Standard Deviations Scores (SDS) by comparison of weight and height to the general population using the software package growth analyzer 3.5 containing the Dutch reference growth charts for the general population from 1997 , 50. Thed) was computed. This was done by computing the difference between estimated means divided by the square root of the standard deviations of the 2 groups. An effect size of 0.20 is considered small, of 0.50 moderate, and 0.80 large. To correct for multiple testing and to determine the significance of the results, Bonferroni correction was applied by dividing the significance level by the number of independent traits in each developmental domain.The data were analyzed using SPSS version 17.0 . As first step we compared the maternal and demographic characteristics of twins in the IVF group versus all DZ NC twins. In a second step, the IVF group was compared to a group of matched NC twins. Matching of IVF and NC pairs was done by using the “duplicate case” option in SPSS. Differences in proportions for parental and birth characteristics between IVF and NC twins were tested using chi-squared tests. For the continuous dependent variables, ANOVA was used to compare the means for maternal and twin pair characteristics. The mixed models procedure and generalized estimating equations  were usFirst, parental characteristics were compared between the IVF twins and the unmatched NC twins. Results are given in To investigate the possible risks of IVF on health, growth, motor development, and problem behaviors we obtained a control group of 1504 twin pairs who were matched on maternal age, gestational age, educational level, zygosity, and smoking behavior. Comparisons of the IVF pairs with the NC pairs matched on maternal and birth characteristics are given in P = 0.023). As shown in Both first- and second-born IVF twins had lower birth weights and lengths than matched NC twins, but the effect was augmented in second-born twins. However, the proportion of children with a birth weight lower than 1500 grams is not different between second-born IVF and matched NC controls. In addition, birth weight discordance was found to be larger in the IVF twins than in matched NC twins. When the analyses were restricted to primiparous mothers, the differences in birth length and weight and birth weight discordance disappeared, with the exception of birth weight of the first born twin  twins with respect to motor milestones, growth, and behavioral problems during childhood. To control for possible confounding factors, only DZ twins were included, and the NC control group was matched on birth cohort, maternal age and educational level, smoking behavior during pregnancy, and gestational age. Although the perinatal outcomes appear to be slightly worse in IVF twins, the course of postnatal development is very similar in IVF and NC twin children. For the IVF pregnancies, maternal age was higher and more mothers were primiparous compared to NC pregnancies. Both factors increased the risks for adverse effects on perinatal outcomes. In our data, this was reflected in the higher proportion of preterm births in the IVF group compared to the NC twins. To control for these differences in demographic and maternal characteristics, we matched on these variables. After matching, the results suggest a slight effect of IVF/ICSI treatment on birth weight and length and time in incubator. This effect is probably due to parity. When only primiparous mothers were included in the analyses, effects were no longer significant. Our results agree with those of studies that controlled for chorionicity , 13 but In agreement with other studies , 52, we There are almost no studies that compared growth of IVF and NC twins. Until age 3, earlier studies found no evidence for differences in growth measures between IVF and NC twins , 24. TheIn agreement with other studies we did not observe a delay of the gross motor development in the IVF twins compared to the NC twins , 27–30. We reported no differences in externalizing behavior and attention problems between the IVF and NC children. The results were found for both parental ratings and were further confirmed by the ratings of the teachers. The confirmation by the teacher ratings is important because the teacher is unaware of the means of conception. The results are in agreement with an earlier study with 5-year old twins  which shA limitation of the current study is that the results rely entirely on self-reports of the mode of conception. A study of Raj and Morley in 2007  suggesteIn summary, children born after IVF develop similarly to NC children. Regarding growth, motor development, and behavior problems IVF twins do not differ from NC twins. Parents conceiving twins via IVF can assume that the development of their children will be similar to that of NC twins. Nonetheless, the risk of adverse obstetric outcome in IVF twin remains considerably higher than in NC twins and should not be underestimated .