The purpose was to examine the association between paternal race/ethnicity and very low birth weight stratified by maternal race/ethnicity.Birth data for Tarrant County, Texas 2006–2010 were analyzed. Very low birth weight was dichotomized as yes  and no . Paternal race/ethnicity was categorized as Caucasian, African American, Hispanic, other, and missing. Missing observations (14.7%) were included and served as a proxy for fathers absent during pregnancy. Potential confounders included maternal age, education, and marital status, plurality, previous preterm birth, sexually transmitted disease during pregnancy, smoking during pregnancy, and Kotelchuck Index of prenatal care. Logistic regressions were stratified by maternal race/ethnicity. Odds ratios and 95% confidence intervals were calculated.Of 145,054 births, 60,156 (41.5%) were Caucasian, 22,306 (15.4%) African American, 54,553 (37.6%) Hispanic, and 8,039 (5.5%) other mothers. There were 2,154 (1.5%) very low birth weights total, with 3.1% for African American mothers and 1.2% for all other race/ethnicities. Among Caucasian mothers, African American paternal race was associated with increased odds of very low birth weight . Among Hispanic mothers, African American paternal race  and missing paternal race/ethnicity  were associated with increased odds of very low birth weight.Paternal race/ethnicity is an important predictor of very low birth weight among Caucasian and Hispanic mothers. Future research should consider paternal race/ethnicity and further explore the association between paternal characteristics and very low birth weight. Marked decreases in infant mortality rates were observed in the United States during the 20th century , an indiLow birth weight has been associated with paternal age, height, low birth weight, heavy/prolonged lead exposure, and may potentially be related to paternal educational level . Abel anInfant vital statistics are tabulated by maternal race/ethnicity, and many studies of racial/ethnic disparities in birth outcomes follow suit ,10,17. CThe United States is expected to move towards a majority-minority population by the year 2043 with expected changes in interracial unions and childbirth . ChangesFew studies examine racial/ethnic disparities in birth weight among infants born to multiracial families of Hispanic origin . AnalysiAlthough maternal race/ethnicity may contribute more greatly to birth outcomes, paternal race/ethnicity merits closer examination and is not always considered in health disparities research -24. The A cross-sectional analysis of birth data for Tarrant County, Texas from 2006–2010 was performed. Live birth data were obtained from the Texas Department of State Health Services Vital Statistics Bureau. A total of 145,054 births were included. Data analysis was approved by the UNT Health Science Center Institutional Review Board.The outcome of interest was very low birth weight (VLBW). VLBW was dichotomized as yes for birth weights <1,500 grams and no for birth weights ≥1,500 grams.Maternal and paternal characteristics were examined as risk factors for VLBW. These risk factors included maternal race/ethnicity , maternal age , maternal education , maternal marital status at birth , plurality , previous preterm birth , sexually transmitted disease (STD) during pregnancy  , smoking during pregnancy , the Kotelchuck Index of prenatal care , and paternal race/ethnicity . Due to the high number of missing data for paternal race (14.7%), missing observations were included as a level of paternal race/ethnicity. This allowed the data for those individuals to be included in the regression models and served as a proxy for fathers absent during the pregnancy. The Kotelchuck Index, also called the Adequacy of Prenatal Care Utilization (APNCU) Index, combines two crucial elements obtained from birth certificate data, when prenatal care began (initiation) and the number of prenatal visits from when prenatal care began until delivery (received services), into a single summary score. It does not measure the quality of prenatal care and is preferable to other indices because it includes a category for women who receive more than the recommended amount of care (adequate plus) .All analyses were performed with SPSS version 19.0 for Windows software. Descriptive statistics are provided for variables by VLBW (yes or no). Differences in variables by VLBW status were calculated using chi-square analysis , and almost half of mothers had more than a high school education (47.5%). Most mothers had a single birth (96.8%), did not smoke during their pregnancy (94.9%), and did not have an STD during their pregnancy (96.8%). Few mothers (1.3%) had a previous preterm birth, and 60% of mothers were married. Approximately a third of mothers had adequate prenatal care based on the Kotelchuck Index (36.7%), while almost another third had inadequate care (30.9%). Paternal race/ethnicity was 36.1% Caucasian, 12.3% African American, 32.3% Hispanic, 4.6% other, and 14.7% missing.A statistically significant difference by VLBW status was observed for maternal race/ethnicity (p < 0.001), maternal age (p < 0.001), maternal education (p = 0.008), Kotelchuck Index (p < 0.001), plurality (p < 0.001), previous preterm birth (p < 0.001), smoking during pregnancy p = 0.002), paternal race/ethnicity (p < 0.001), and maternal marital status (p < 0.001). No difference in VLBW status pregnancy was observed by having an STD during the pregnancy. Table , paternaIn crude analysis, African American mothers had a 2.68 times greater odds (95% CI: 2.41-2.98) of VLBW as compared to Caucasian mothers. Hispanic and other mothers were not significantly different than Caucasian mothers. Adjusted ORs from multiple logistic regression analyses stratified by maternal racial/ethnic groups are displayed in Table Multiple plurality was significantly associated with higher odds of VLBW in all racial/ethnic groups, {Caucasians , African Americans , Hispanics , others }. Previous preterm birth was significantly associated with higher odds of VLBW in African American  and Hispanic  mothers, but not among Caucasian or other mothers. Having an STD during the pregnancy was significantly associated with a lower odds of VLBW among African American mothers  but not among the other racial/ethnic groups. Smoking was significantly associated with higher odds of VLBW among African American mothers , but not among the other racial/ethnic groups. Among all racial/ethnic groups, inadequate, intermediate and adequate plus Kotelchuck Index categories were significantly associated with a higher odds of VLBW compared to adequate Kotelchuck Index . Among Hispanic mothers, having an African American father was associated with a 66% increased odds of VLBW  and missing father was associated with a 65% increased odds of VLBW . Paternal race/ethnicity was not associated with VLBW among African American or other mothers.Paternal race/ethnicity is an important predictor of very low birth weight among non-Hispanic Caucasian and Hispanic mothers. This relationship is significant apart from marital status and maternal factors such as age, plurality, and smoking. Among non-Hispanic Caucasian mothers, African American paternal race was associated with increased odds of VLBW compared to non-Hispanic Caucasian paternal race. Studies have previously identified a graded increase in risk for stillbirth among infants born to families with non-Hispanic Caucasian maternal and African American paternal race, African American maternal and non-Hispanic Caucasian paternal race, and African American maternal and paternal race, respectively . SimilarThe increased odds of VLBW related to paternal race/ethnicity exist independently of marital status. Sullivan and colleagues found that although infants born to unmarried mothers were at higher risk for low birth weight and pre-term birth than married mothers, this association failed to explain the African American-Caucasian disparity in birth outcomes; however, paternal race/ethnicity was not examined in this study . PaternaThe present study confirms that the lack of a paternal record is associated with greater odds of VLBW among Hispanic women but not among non-Hispanic Caucasian, African American, or other women. Previous research indicates that unmarried African American, non-Hispanic Caucasian, and Hispanic mothers with no paternal record on the birth certificate are at greater risk of delivering a low birth weight infant when compared to married mothers . Other sFactors such as stress, increased susceptibility to stress, the presence of racism and its potential to increase or exacerbate stress, and racial/ethnic differences in biological responses to stressors have been considered possible explanations to racial/ethnic disparities in birth outcomes, each bearing some merit, but lacking in capacity to completely clarify the pathway to differences in health . LongituThe large sample size and the inclusion of paternal/race ethnicity in the analysis are clearly strengths of this study. However, paternal age was not included in the analysis due to missing data, and other factors such as paternal/maternal income and national origin of Hispanic populations were not included in the analysis. This study is specific to Tarrant County Texas, and results may not be applicable to other study populations. Maternal risk factors for specific medical conditions were not available from the birth certificate data. Additionally, the Kotelchuck Index, also called the Adequacy of Prenatal Care Utilization (APNCU) Index, does not measure the quality of prenatal care. While it is preferable to other indices because it includes a category for women who receive more than the recommended amount of care (adequate plus), the adequate plus category may include complex pregnancies that required more visits. For the current analysis, the adequate category was used as the reference group as opposed to the adequate plus.Paternal characteristics are associated with negative birth outcomes; however, the extent of the influential effects of paternal characteristics is not fully understood. Existing evidence supports the continued exploration of paternal factors such as race/ethnicity with VLBW, and programs and policies aimed at improving birth outcomes should include fathers and paternal factors in the provision of services. Other paternal characteristics such as age and education should also be examined in relation to birth outcomes. Finally, it is unclear if the association between paternal race/ethnicity and birth outcomes is reflective of social constructs such as cultural practices or familial/social support that may be better captured by measuring other factors. Future research is needed to understand the stressors that may be unique to multi-ethnic unions and among mothers where paternity is absent, even in the presence of protective factors such as Hispanic maternal ethnicity. Additional research should include a prospective approach to capture family and cultural dynamics before, during, and after pregnancy to clarify these complex relationships.


All over the the world, preterm birth is a major cause of death and important neurodevelopmental disorders. Approximately 9.6% (12.9 million) births worldwide are preterm.In this review, databases such as PubMed, EMBASE, ISI, Scopus, Google Scholar and Iranian databases including Iranmedex, and SID were researched to review relevant literature. A comprehensive search was performed using combinations of various keywords.Cerebral palsy especially spastic diplegia, intellectual disability, visual (retinopathy of prematurity) and hearing impairments are the main neurodevelopmental disorders associated with prematurity.The increased survival of preterm infants was not associated with lower complications. There is now increasing evidence of sustained adverse outcomes into school age and adolescence, for preterm infants. Preterm birth is a major cause of death around the world and is one of the major health problems. Approximately 9.6% (12.9 million) births worldwide are preterm. The prevalence of preterm and low birth weight (LBW) births in United States is estimated at 8.2% per year . Nearly Overall, from 121 million neonates born each year, almost 23 million have LBW and the majority of them are in developing countries and cause by premature birth . LBW preIn recent years, with advances in prenatal care and starting neonatal intensive care units, the survival rate of premature infants, low and very low birth weight (VLBW) has increased significantly , 13. HowPremature infants are at risk of major and minor deficits, such as cerebral palsy, cognitive and speech delays, motor and visual deficits, psycho-social and behavioral disorders, and dysfunction at school -21. ThisData of this review were collected from our previous studies plus various data such as PubMed, EMBASE, ISI Web of science, Scopus, Google Scholar and Iranian databases including Iranmedex, and SID. A comprehensive search was performed using the combinations of the keywords “neurodevelopment, impairment, preterm birth, low birth weight” to review the relevant literature. The searches were performed using Boolean operators OR, AND between main phrase and the mentioned keywords were extracted from specific themes of the topic under study. A search strategy was built applying advanced search capability of the search engines. Based on this search strategy, only those articles were retrieved that had one of the first four keywords either in the title or the abstract. This strategy retrieved 150 articles. The inclusion criteria was set out in a way that only articles that explicitly dealt with neurodevelopmental outcomes after preterm birth were included. We also looked at the reference list of the retrieved papers and searched other search engines. A total of 150 articles were found in the primary search but after elimination of duplicates or irrelevant papers, only 79 records remained to be reviewed. The rational for selecting these articles were their popularity among researchers in the field. All published data from 1999 to 2013 is included in this review.The main disorders associated with prematurity include cerebral palsy especially spastic diplegia, intellectual disability, hearing loss, and visual impairment associated with retinopathy of prematurity. These impairments can occur together or separately during developmental periods, and they are sometimes complicated by progressive hydrocephalus or chronic seizures . They arThese disabilities are 2 to 3 times more likely to occur in LBW infants compared to normal weight infants, and its prevalence increases with a more prametuarity and lower weight at birth birth , 24, 25.Cerebral palsy with various intensities and types is the most common developmental disorder of preterm infants and is associated with long-term disabilities. Early signs of cerebral palsy usually appear before three years of age. Infants with cerebral palsy compared with normal children often have slower developmental stages -30. EstiCerebral palsy, based on the type and nature of the motor disability and according to the neurological signs and symptoms, is classified into different types. The classification is also based on pyramidal or extrapyramidal pathways involved and lesion localization  . CerebraIntellectual disability or mental retardation (MR) is often accompanied by one or more disability states especially cerebral palsy . CollierCollier studied the risk factors associated with LBW and their impact on CP and mental retardation and emphasized that unwanted pregnancy and cigarette smoking during pregnancy increases the incidence of LBW; and prevention of these risk factors can prevent 32 cases of cerebral palsy and 159 cases of mental retardation per year .Studies showed that preterm infants had 20 times higher risk of hearing loss than full-terms with normal weight , 47. TheModerate and mild sensorineural hearing loss (25 dB to 59 dB) can lead to delayed speech and language development with the incidence of 6% to 8% of LBW infants. The high prevalence of chronic otitis with middle ear effusion and conductive hearing loss in preterm infants with LBW has been reported, and it might be due to the association with eustachian tube dysfunction, dolichocephalic head, muscular hypotonia, and prolonged intubation . In VLBWRetinopathy of prematurity (ROP) is one of the most common causes of visual loss in infants with LBW . ROP remGestational age of less than 26 weeks is the most important factor associated with visual impairment. It seems that hypoxia, arterial carbon dioxide pressure changes, arterial pH, oxygen consumption with high dosage, and being exposed to light are influential factors in visual defects in infants with LBW . ResearcIntraventricular hemorrhage is the major problem of premature infants in neonatal intensive care units around the world . AccordiAlthough assessment of major disabilities is easy but detecting minor impairments seems difficult . The ratAs shown in the former studies, the cognitive outcome is inversely correlated with gestational age and birth weight. Other factors that have a negative impact on cognitive outcomes are intrauterine growth retardation, perinatal infection, broncho-pulmonary dysplasia, intra ventricular hemorrhage, cystic periventricular leukomalacia, ventricular dilatation after hemorrhage, and environmental factors such as socioeconomic status, and education level of the mother. It was found that the cognitive function in preterm children were on average below term babies . The IQ Communication skills including auditory, visual, verbal symbolic learning systems (i.e. language), and speech production is based on academic learning and social communications . The preAccording to the previous studies, VLBW children and very preterm infants are weaker than term children regarding language performance. These language problems can still be seen in primary schools meaning the time that language development is more stable and becomes more like that of the adults . SansaviLee in a study on 65 preterm children with 9 to 16 years of age and history of LBW and 35 full-term children with normal birth weight found that practical IQ score, verbal IQ, expressive and language skills, understanding syntax, language processing speed, verbal memory, decoding, reading, and comprehension in preterm children were significantly less advanced . OverallPrematurity or LBW is associated with neuromotor sequels which will extend to the childhood period . Karimi Preterm birth is the leading cause of neurobehavioral impairment and disability causing huge economic burden . The ranAccording to the Vieira review, nine studies have been conducted on evaluating neurodevelopment during the preschool period (3-5 years). In those studies, moderate or severe impairment of neurological function was defined as lower and upper limb motor function problems, inability to ambulate independently and visual and hearing defects. Approximately, 17%-23% of very preterm infants (birth age of less than 30 weeks) were noticed with this dysfunction in preschool stage, while it was observed in only 12% of children with birth age of 31-34 weeks. The percentage of cerebral palsy in very preterm born children at preschool was about 11%-25% and in children with birth-age of 31 to 34 weeks was 6%-15%. The majority of the risk factors of neurological dysfunction of very preterm children with LBW in preschool children were related to the neonatal period, including prolonged mechanical ventilation, grade 3 or 4 of IVH, ROP, low Apgar score, and seizure during the perinatal period. In addition to all these, low levels of maternal education was considered as one of the factors contributing to the neurological dysfunction at this age. But, the factors affecting neurological dysfunction at ages of 6-12 years, in addition to prolonged mechanical ventilation in the neonatal period, were grade 3 or 4 of IVH, periventricular leukomalacia, and mother’s age of 40 years or more at the time of delivery .Early detection can lead to early interventions . Lund, iWith the increasing number of follow-up studies on preterm or LBW infants, it is noted that the range of disorders and learning disabilities has also a greater range . A meta-Aamoudse-moens et al. studied the developmental status of academic skills in four 12-years-old children with the history of preterm birth and VLBW compared with same age full-term born children. National system of DNP  was used for evaluating the numerical reasoning and early linguistic skills in preschool stage and reading simple and complex words, comprehension, spelling, mathematics, and calculus test in primary school stage were used for evaluation. In preschool stage, very preterm children were comparable with their peer full-term in terms of basic linguistic; but in numerical reasoning skills, they were 0.7 standard deviation (SD) poorer. In the primary school, preterms were 0.3 of SD lower in reading difficult and complex words and 0.6 of SD lower in mathematics and calculus; but in terms of comprehension and spelling, they were comparable to their full-term peers. These children were more likely to renew an academic year while their academic skills would not develop. Therefore, trying to develop intervention methods can help in identifying and reducing academic weaknesses of the preterm born children . Five toLitt also studied 181 teenagers with mean age of 14.8 years and birth weight lower than 1000 grams and discovered that these children as compared with their peer full-term children with normal birth weight had lower IQ score, lower academic achievement, and poorer functional performance and higher mathematics learning disability . In anotThe major clinical outcomes that are important for preterm infants and their families are survival and normal long term neurodevelopment. In recent years, with advances in perinatal care, the survival rate of premature infants has increased significantly, but this advancement was not associated with lower complications, and infants who survived suffered more intensely from multiple disabilities. For infants born preterm, there is now increasing evidence of sustained adverse outcomes into school age and adolescence, and the majority of them require intensive and continuous care. In line with the need to reduce infant mortality, the need to reduce the complications in premature infants should be considered by health system policymakers.One of the strengths of our study is the subject of study because it is a major health problem due to high mortality and chronic disorder associated with it across the world especially in developing countries such as Iran.We found that there is a gap between the high technology and quality of acute medical care and loss or no neurodevelopmental care for high risk neonates and infants in NICUs by specialists and caregivers. No awareness of specialists and nursing of long-term neurodevelopmental outcome for high risk neonates.Limitation of access to journals and articles due to international sanctions against Iran.


Prenatal exposure to perfluoroalkyl substances (PFAS) has been associated with lower birth weight in epidemiologic studies. This association could be attributable to glomerular filtration rate (GFR), which is related to PFAS concentration and birth weight.We used a physiologically based pharmacokinetic (PBPK) model of pregnancy to assess how much of the PFAS–birth weight association observed in epidemiologic studies might be attributable to GFR.We modified a PBPK model to reflect the association of GFR with birth weight (estimated from three studies of GFR and birth weight) and used it to simulate PFAS concentrations in maternal and cord plasma. The model was run 250,000 times, with variation in parameters, to simulate a population. Simulated data were analyzed to evaluate the association between PFAS levels and birth weight due to GFR. We compared simulated estimates with those from a meta-analysis of epidemiologic data.The reduction in birth weight for each 1-ng/mL increase in simulated cord plasma for perfluorooctane sulfonate (PFOS) was 2.72 g , and for perfluorooctanoic acid (PFOA) was 7.13 g ; results based on maternal plasma at term were similar. Results were sensitive to variations in PFAS level distributions and the strength of the GFR–birth weight association. In comparison, our meta-analysis of epidemiologic studies suggested that each 1-ng/mL increase in prenatal PFOS and PFOA levels was associated with 5.00 g  and 14.72 g  reductions in birth weight, respectively.Results of our simulations suggest that a substantial proportion of the association between prenatal PFAS and birth weight may be attributable to confounding by GFR and that confounding by GFR may be more important in studies with sample collection later in pregnancy.http://dx.doi.org/10.1289/ehp.1408837Verner MA, Loccisano AE, Morken NH, Yoon M, Wu H, McDougall R, Maisonet M, Marcus M, Kishi R, Miyashita C, Chen MH, Hsieh WS, Andersen ME, Clewell HJ III, Longnecker MP. 2015. Associations of perfluoroalkyl substances (PFAS) with lower birth weight: an evaluation of potential confounding by glomerular filtration rate using a physiologically based pharmacokinetic model (PBPK). Environ Health Perspect 123:1317–1324;  Perfluoroalkyl substances (PFAS) are synthetic compounds that are resistant to degradation and have been found worldwide in environmental media and biota, including humans. The most widely studied PFAS are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). PFOS was an ingredient in the Scotchgard stain repellent manufactured by 3M, but the company decided to stop producing PFOS in 2002 after it had been found in wildlife and humans . PFOA isMany epidemiologic studies have reported an association between maternal and cord blood PFAS levels and reductions in birth weight . AlthougIn this study, we assessed how much of the epidemiologic association between prenatal PFOS and PFOA (PFAS thereafter) exposure and birth weight could be attributable to confounding by GFR. We modified a recently developed physiologically based pharmacokinetic (PBPK) model of PFAS during pregnancy  to refleOverview. We used a PBPK model to run Monte Carlo simulations of a study population and to generate pairs of predictions for PFAS level and birth weight. PBPK-derived estimates were subsequently analyzed by linear regression. We also performed a meta-analysis of published epidemiologic studies of prenatal PFAS exposure and birth weight to obtain summary effect estimates. Results obtained from simulated PFAS levels and birth weights were compared with results from our meta-analysis to evaluate how much of this association might be attributable to the influence of GFR.The PBPK model. We modified a published PBPK model of PFOA and PFOS during pregnancy ]. The initial amount of PFAS in the different maternal tissues (Amountt) at each Monte Carlo simulation (i) was computed as the product of the initial plasma PFAS level , the tissue:plasma partition coefficient (Partitiont) and the tissue volume (Volumet):We also modified the model so that the initial body burden (at the beginning of pregnancy) and intake rate during pregnancy are calculated based on an initial plasma PFAS level [Ct(i) = Cinitial(i) × Partitiont(i) × Volumet(i). [1]AmountMaternal PFAS intake rate during pregnancy was estimated from initial plasma PFAS level. To estimate maternal PFAS intake rate during pregnancy, we assumed the initial plasma PFAS level to be at steady state. The hourly intake rate was calculated accordingly using a rearrangement of a classic steady state equation that accounts for compound-specific half-life (hours), volume of distribution (liters), and dosing interval (hours) :(i) = Cinitial(i) × Volume of distribution(i) × Dosing interval × ln(2)/Half-life, [2]Intake (ng/hr)where the volume of distribution was calculated based on partition coefficients and organ volumes, the dosing interval was 1 hr (simulation time increment), and the half-lives of PFOS and PFOA were 47,304 hr (5.4 years) and 33,288 hr (3.8 years) .ratio) as the ratio of the observed GFR for each subject to the mean GFR at that gestational age GFRratio and birth weight derived from three studies, as described above. This was accomplished by using the equation derived from the aforementioned regression and randomly sampling an error term based on the distribution of residuals:Then we calculated a birth weight according to the meta-analytic regression between GFR(i) = Intercept + β × GFRratio(i) + Residual(i), [4]Calculated birth weight (g)ratio, and the residual was sampled from a distribution with a mean of 0 g, an SD of 441 g, and ranging from –882 g to 882 g (± 2 SDs). Fetal growth in the original PBPK model was described using a time-dependent fetal growth curve (t) by the ratio of calculated birth weight on the reference fetal weightt at delivery . For each simulation (i), the time-course of fetal weight  was described using the following equation:where the intercept was 3,376 g, the β was 175.5 g per 1-unit increase in GFRth curve . We adjut(i) = /3,509 g) × Reference fetal weightt. [5]Fetal weightPBPK model global sensitivity analysis. Because the PBPK model used herein incorporates > 40 parameters that can vary within a population , we first ran a sensitivity analysis to identify parameters with the highest relative influence on maternal plasma PFAS levels across pregnancy and cord plasma PFAS levels at delivery. We opted for the Morris global method, which evaluates parameter sensitivity over a range of physiological scenarios by taking the mean of many local sensitivity analyses calculated over the entire parameter space, thus accounting for interactions  sampled values for sensitive parameters identified in the global sensitivity (b) sampled a plasma PFAS level from the published distributions at the first blood sample collection time point; c) adjusted the initial plasma level (at the time of conception), by iterative model simulations, to obtain matching simulated and sampled PFAS level at the time of the first blood sample collection (tolerance: 0.1%); and d) simulated a complete pharmacokinetic profile based on the initial plasma level. We visually compared the distribution of simulated plasma PFAS profiles from the Monte Carlo iterations with the distribution of observed PFAS levels in the second blood samples from the two reports mentioned above.sitivity ; b) sampMonte Carlo simulation. We used a Monte Carlo procedure to simulate population PFOA and PFOS levels across pregnancy. At each Monte Carlo iteration, the PBPK model sampled values for sensitive parameters identified in the global sensitivity analyses and initial blood PFAS levels from probabilistic distributions  included in our meta-analysis (described below). Monthly simulated maternal plasma PFAS levels, simulated cord plasma levels at delivery, and calculated birth weight were collected from simulations to be used in regression models of PFAS and birth weight. We ran 250,000 Monte Carlo iterations to achieve convergence in the PFAS–birth weight linear regression coefficient (β).ibutions  before sibutions ], we useSensitivity analyses. We evaluated the influence of different assumptions on the association between PBPK-derived PFAS levels and birth weight. In addition to analyses noted above, we ran multiple Monte Carlo simulations with different parameters for PFAS distributions (higher and lower means and standard deviations) and different coefficients for the GFR–birth weight association. Specifically, we halved or doubled these three parameters, one at a time. We also ran Monte Carlo simulations with different sampling seeds to evaluate reproducibility. We identified two studies that evaluated PFOA half-life in populations exposed through drinking water; Meta-analysis of PFAS–birth weight epidemiologic studies. We identified human studies published in English in 2012 or earlier using the PubMed (http://www.ncbi.nlm.nih.gov/pubmed) search terms “birth weight” and “perfluorooctane sulfonate” or “perfluorooctanoic acid.” This identified articles with the search terms in the title, abstract, or key words. To be eligible for inclusion in the analysis, the study had to have results available from a multiple regression model of birth weight (grams) as a function of PFOS or PFOA in nanograms per milliliter concentration in maternal blood from pregnancy or cord blood. In one case . For example, the most sensitive parameter for PFOS levels in cord plasma was the free fraction in fetal plasma . In a one-at-a-time sensitivity analysis, a 10% change in this parameter was associated with an 8.9% change in simulated cord plasma PFOS level. In comparison, a 10% change in the liver volume  was associated with a 0.9% change in simulated cord plasma PFOS level.To assess model accuracy, we simulated maternal plasma PFAS levels based on the first of the two serial measurements of PFAS from two published studies  and visuIn linear regression analyses, the association between simulated maternal and cord plasma PFAS levels and birth weight was dependent on the time elapsed after conception. For both PFOA  and PFOSIn sensitivity analyses, we evaluated whether the results were robust to changes in initial plasma PFAS level distributions (mean and SD), variations in coefficients for the GFR–birth weight association and different Monte Carlo sampling seeds (reproducibility). These analyses showed that the strength of the simulated PFAS–birth weight association  is influenced by initial plasma PFAS level distributions and the GFR–birth weight coefficient: Stronger associations were obtained with lower mean initial plasma PFAS levels and lower SDs, and with higher GFR–birth weight coefficients . When moMeta-analysis of epidemiologic studies. All studies of prenatal PFOA reported an association with reduced birth weight, with β coefficients ranging from –2.1 g to –64.4 g per nanograms per milliliter increase in PFOA levels . For PFOA, the corresponding coefficient was –0.006, p = 0.98. Although the meta-regression results support our hypothesis for PFOS, the lack of support for PFOA could be attributable to the small number of studies included, and other sources of heterogeneity.When our default assumptions were applied, the association between simulated maternal and cord plasma PFAS levels at the time of delivery and birth weight represented a substantial proportion of the association observed in our meta-analysis of epidemiologic studies. This suggests that epidemiologic studies presented herein, which have not controlled for GFR, might have overestimated the influence of prenatal exposure to PFAS on fetal growth. Our results also suggested that GFR had less influence on PFAS levels in maternal plasma early in pregnancy. In a meta-regression analysis of the epidemiologic data in In light of these results, epidemiologic studies investigating the effects of prenatal PFAS on fetal growth should account for the influence of GFR. Different approaches could be considered. An option would be to sample maternal plasma before pregnancy or during the first trimester, when changes in GFR have not yet influenced PFAS significantly according to simulated results. Statistically adjusting for GFR estimated from plasma creatinine levels or cystatin C levels  could alOur results also have implications with regard to future meta-analyses of prenatal PFAS and birth weight. As noted by r = 0.55–0.69) and in the r = 0.27–0.30), although correlations were statistically significant only in the Certain assumptions might have introduced bias in our study. Because individual-specific data on GFR, PFAS, and birth weight were not available, we could evaluate the PBPK model validity only on a population level. Should extensive individual-specific measurements be available during pregnancy, the model could be further calibrated and evaluated. Nevertheless, when we simulated plasma PFAS levels across pregnancy in women from two studies who had their blood levels measured twice, simulated levels followed a decline in PFAS levels that closely matched reported levels. Because the simulated association between PFAS and birth weight was shown to be sensitive to the distribution of PFAS levels, the strength of the association between simulated PFAS levels and birth weight from this study cannot be compared with epidemiologic studies or meta-analyses with a different distribution of plasma PFAS levels. The coefficient of the GFR–birth weight association used in the Monte Carlo simulation was also shown to be a sensitive parameter. Should the true association between GFR and birth weight be stronger or weaker than the meta-analytic relation used in this study, one would expect the simulated association between PFAS and birth weight to change accordingly . We also did not account for the potential association between GFR and initial PFAS concentration at conception. For example, prepregnancy GFR was correlated with GFR during pregnancy in the The meta-analysis for PFOA that we did was based on data for > 4,000 subjects. The more formal meta-analysis by n = 953), revealed a significant association between estimated GFR and birth weight. When considering all available studies on the subject, we found that large studies consistently demonstrated an association between estimated GFR or indicators of GFR  and birth weight , whereas results from smaller studies have been inconsistent . Given the new evidence, there is reason to believe a true association exists between maternal GFR during pregnancy and birth weight. Yet our results, which are based on the association between GFR and birth weight from three studies with individual-specific paired GFR and birth weight measurements  PDFClick here for additional data file.


P < 0.0001) higher in the malignant (n = 16) versus benign (n = 22) tumor cysts. Validation of MCP-1, IL-8, and growth-regulated protein-α (GROα/CXCL1) was performed with ELISA in benign, borderline, and malignant cyst fluids (n = 256) and corresponding serum (n = 256). CA125 was measured in serum from all patients and used in the algorithms performed. MCP-1, IL-8, and GROα are proinflammatory cytokines and promoters of tumor growth. From 5- to 100-fold higher concentrations of MCP-1, IL-8 and GROα were detected in the cyst fluids compared to the serum. Significant (P < 0.001) cytokine response was already established in borderline cyst fluids and stage I EOC. In serum a significant (P < 0.01) increase of IL-8 and GROα was found, but not until stage I and stage III EOC, respectively. These findings confirm that early events in tumorigenesis can be analyzed and detected in the tumor environment and we conclude that ovarian cyst fluid is a promising source in the search for new biomarkers for early ovarian tumors.Mortality rates for epithelial ovarian cancer (EOC) are high, mainly due to late-stage diagnosis. The identification of biomarkers for this cancer could contribute to earlier diagnosis and increased survival rates. Given that chronic inflammation plays a central role in cancer initiation and progression, we selected and tested 15 cancer-related cytokines and growth factors in 38 ovarian cyst fluid samples. We used ovarian cyst fluid since it is found in proximity to the pathology and mined it for inflammatory biomarkers suitable for early detection of EOC. Immunoprecipitation and high-throughput sample fractionation were obtained by using tandem antibody libraries bead and mass spectrometry. Two proteins, monocyte chemoattractant protein-1 (MCP-1/CCL2) and interleucin-8 (IL-8/CXCL8), were significantly ( EOC represents a very heterogeneous disease with widely varying histology, pathogenesis, and clinical behavior Development of epithelial ovarian neoplasm has been related to the process of ovulation and increased ovulations per life increase the risk of getting EOC EOC comprises the majority of malignant ovarian tumors and is one of the most deadly cancers among women in the Western world. Each year approximately nine of 100,000 women will be diagnosed and five of 100,000 will die from EOC Numerous studies have been undertaken to find an alternative to the current 30-year-old tumor marker, cancer antigen 125 (CA125) n = 256) and corresponding blood serum (n = 256). Data were related to serum levels of the established EOC biomarker CA125. CA125 were measured in the ovarian cyst fluid as well and correlated with the serum levels.We studied ovarian cyst fluid from benign, borderline, and malignant cystic epithelial ovarian tumors in order to identify inflammatory biomarkers for early diagnosis of EOC. Exploration of the immunoproteome of ovarian cyst fluid from 38 patients was performed by a direct targeting method: immunoprecipitation with selected monoclonal antibodies, specific for 15 cytokines and growth factors known to be involved in the immune response in cancer. This was followed by mass spectrometry (MS). Identified proteins with the highest significance, Receiver operator characteristic (ROC), area under the curve (AUC), and the greatest increase in fold change were chosen for validation in a larger set of ovarian cyst fluid . Fifteen other samples turned out to be metastasis from cancers other than EOC. The remaining samples from 256 women were available for analysis. CA125 was measured in the blood samples from all patients with ovarian cysts. The tumors were staged according to FIGO classification and histopathology, and grade was established by an experienced pathologist  was used to mine the inflammatory profile of the ovarian cyst fluid  . In this approach, potential biomarkers in ovarian cyst fluid are targeted by selected monoclonal antibody mixtures.We used 38 cyst fluid samples and two antibody mixtures (AB mix I and AB mix II). The division of the antibodies into two groups was based on molecular weights and some structural motifs of the antibodies Tables  and S1.μL cyst fluid was added to 300 μL 150 mmol/L TrisHCl, 0.15 mol/L NaCl, and 0.1% Tween 20 containing protease inhibitor cocktail  with 50 μL 50% v/v immobilized Antibody Mix I agarose beads  in an perfluorodecyltrichlorosilane (FDTS)-modified fritted 96-deepwell filter plate . The plate was sealed, shaken at 4°C for 8 h, and then centrifuged at 1500 rpm for 2 min to collect the unbound fraction. The entire unbound fraction was transferred to 50 μL 50% v/v immobilized Antibody Mix II agarose bead  in a FDTS-modified fritted 96-deepwell filter plate (Nunc). The plate was sealed, shaken at 4°C for 8 h, and then centrifuged at 1500 rpm for 2 min to collect and remove the unbound fraction. Each well of the 96-well filter plates was washed twice with 500 μL 1 mol/L urea, 0.1% CHAPS  dimethylammonio]-1-propanesulfonate), and phosphate-buffered saline at pH 7.5.From each sample, 400-μL of 50% isopropanol/acetonitrile (2:1), 0.5% formic acid, and 1% trifluoroacetic acid to yield Fraction B1, secondly with 100 μL 3 mol/L guanidine thiocyanate and 0.5% Triton X100 (90°C) to yield Fraction B2a, and thirdly with 100 μL 2 mol/L thiourea, 4 mol/L urea, 1% CHAPS, and 50 mmol/L Tris-HCl pH 7.5 to yield Fraction B2b.Proteins bound to the antibody Mix I and Mix II beads were differentially eluted, firstly with 100 μL aliquot of each eluted fraction was added to 200 μL of buffer in a bioprocessor containing either a cation exchange ProteinChip array  or an immobilized Cu ProteinChip array . After 45 min of incubation with shaking, the arrays were washed once with 200 μL of the buffer and then rinsed with water. After adding sinapinic acid, the chip-bound proteins were profiled using a PCS4000 mass spectrometer (Ciphergen).A 30-Data were acquired using CiphergenExpress (Fremont). Mass calibration was performed using external calibrants. Intensity normalization was based on the total ion current using an external normalization factor, and baseline subtraction was performed. Peak detection was performed in CiphergenExpress using the criteria that a peak must have a signal/noise ratio of 3:1 and be present in 20% of the spectra.α previously reported to be one of the most highly induced pro-inflammatory cytokines and a potential tumor marker for EOC IL-8 and MCP-1, the two identified proteins with highest significance in the immunoprecipitation–MS analyses, were further validated individually and together with the currently used marker CA125. GROn = 512 samples)  according to the manufacturer's instructions with minor modifications. CA125 in U/mL was measured in blood samples with ELSA-CA125  according to manufacturer's instruction.ELISA was performed on ovarian cyst fluid and serum from 256 patients n = 52 samplesU-test was used to identify peaks with P < 0.001 comparing benign and malignant ovarian cysts in the immunoprecipitation–MS. The protein levels measured with ELISA were subjected to the Mann–Whitney U-test and logistic regression analysis. The regression models were estimated for each marker individually and in combinations to differentiate between patients with benign, borderline, and malignant cysts. ROC was constructed for each model, and the AUC was calculated. A level of P < 0.05 was considered statistically significant.Statistical analyses were performed in SPSS for Windows (version 17), CiphergenExpress (Ciphergen Biosystem) and Prism 5.0 . The Mann–Whitney n = 38) cyst fluid samples, 150 high-quality peaks were detected as differently expressed between benign and malignant samples (P < 0.001). Two of the proteins identified by the immunoprecipitation–MS were MCP-1 and IL-8, with ROC AUC values of 0.82 and 0.80, respectively, and a seven-fold difference in expression. MCP-1 (SwissProt # P13500) had a calculated molecular weight (MW) of 8664.03 Da. IL-8 (SwissProt # P10145) was found in two forms: a full-length protein with a calculated MW of 8918.45 Da, and a truncated form IL-8 (6-77), missing 5 amino acids from the N-terminal, with a calculated MW of 8381.77 Da , IL-8 (756 vs. 7), and MCP-1 (10512 vs. 287 pg/mL) (Table α (median 919 vs. 96), IL-8 (6704 vs. 13), and MCP-1 . The protein concentrations in serum and cyst fluid from the same patient did not correlate. The age of patients in the benign group was almost as high as in the malignant group with a mean of 60 compared to 61 years. Patients with borderline tumors were 10 years younger, at 51 years  differentially expressed comparing benign (n = 156) to borderline tumors (n = 22). CA125 was the only marker that was significantly (P < 0.001) differently expressed in serum from borderline tumors (Table P = 0.004). In serum, the combination of all markers resulted in ROC AUC of 0.78, the same as for CA125 alone  higher expression in early-stage disease when compared with cyst fluid samples from patients with a benign cyst (n = 156) to stage I EOC samples (n = 32). IL-8 was the only marker in serum that was significantly differently expressed (P = 0.006) beyond CA125 (P < 0.001) in stage I EOC serum (Table n = 7) as an “early stage” group (n = 39). The multiple regression analysis of the cyst fluid markers together with serum CA125 in stage I tumors resulted in ROC AUC of 0.76, with CA125 as an independent marker (P = 0.01). CA125 alone reached the same ROC AUC as the combination of all markers in serum  and all malignant samples (n = 78). Significant differences were noted in ovarian cyst fluid for GROα (P < 0.001), IL-8 (P < 0.001), and MCP-1 (P = 0.006)  differences, but MCP-1 (P = 0.99) could not be identified in serum.We compared the protein levels in cyst fluid between benign (6) Table , Fig.2. P < 0.001), and GROα (P = 0.005). In serum our potential biomarkers together with CA125 revealed ROC AUC 0.88, with CA125, IL-8, and GROα as independent markers . The expression levels of the three biomarkers  were compared between benign and all malignant tumors. IL-8 was the best chemokine in predicting malignancy, with ROC AUC 0.73 in cyst fluid and AUC 0.76 in serum. However, no other marker combination showed greater ROC AUC values than CA125 as a single marker with ROC AUC 0.88 .We measured CA125 in ovarian cyst fluid and found a correlation between the cyst fluid and the serum samples, with significant higher levels in the ovarian cyst fluid. Pearson correlation factor is 0.477 with α. The cytokines validated were all increased in early-stage EOC in the cyst fluid, but only IL-8 was a significant marker in serum other than CA125.Because of its closeness to the primary tumor, ovarian cyst fluid hold promise in the search for novel early ovarian cancer biomarkers. Proteins in the fluid are directly produced, degraded, or secreted by tumor cells, surrounding stroma and immune cells, which are involved in tumorigenesis Chemokines are key players in CRI, and the potential biomarkers analyzed in our study are well characterized as proteins involved in carcinogenesis α are both pro-inflammatory chemokines that modulate inflammation and regulate angiogenesis, a process on which tumors depend for growth, survival, invasion, and metastasis α is a potent inducer of senescence in stromal fibroblasts α have been seen in tissue and serum from ovarian cancer patients in comparison to healthy women IL-8 and GROα as cyst fluid biomarkers.Our results show that it may be possible to discriminate between borderline and malignant tumors, even the early malignant tumors from benign ovarian cysts, using MCP-1, IL-8, and GROα in ascites than in serum in EOC has been reported, indicating migration of cytokines from the local environment to the peripheral circulation, supporting our hypothesis The high expression of inflammatory proteins in cyst fluid in early-stage EOC supports our theory that inflammatory markers are confined to the actual tumor and to the ovarian cyst in the early process, and only later secrete to the blood circulation In this study, we focused on inflammatory biomarkers connected to tumorigenesis. We used a direct targeting method, immunoprecipitation with monoclonal antibodies, to avoid or diminish the problem of having high-abundant proteins within the cyst fluid Specific biomarkers of interest in the cyst fluid could be detected by imaging, for example, with labeled antibodies. This is a speculative but interesting option, not only for early diagnosis but for selection of therapy. Cytokines are multifunctional, with different functionality in different stages of the cancer process. Knowledge about their different functions and pathways is increasing exponentially. Identification of the major mediators and the pathways responsible for triggering an inflammatory response in early stages is not only of interest for diagnosis but also provides opportunities to treat and prevent cancer progression using targeting anti-inflammatory approaches.Novel ovarian cancer biomarkers are needed to improve the sensitivity and specificity achieved with the currently used biomarker CA125. When distinguishing benign and EOC ovarian cysts, the diagnostic ability of the marker combination in cyst fluid together with serum CA125 (ROC AUC 0.87) was almost the same as for CA125 alone (AUC 0.88). ROC AUC for the marker combination in the early stage EOC was 0.77, compared to 0.76 for CA125 alone.n = 50%) of early EOC in our cohort. We have to take into account the diversity of the tumor biology of EOC when searching for early cancer markers. A panel with a combination of markers able to cover the multiple variants of EOC could improve early detection. Early markers are likely to be found in proximity to the tumor, as in the case of the low-abundant cytokines in our study.Early diagnosis of ovarian cancer is very challenging because of the great heterogeneity of the disease, the absence of preclinical lesions in the more aggressive tumors, as well as the relatively low prevalence. Markers that are positive in aggressive tumors are often negative in low-grade tumors and vice versa α were found in the cyst fluids compared to serum, and the concentration increased with malignancy. Significant cytokine response was already detectable in borderline cyst fluids and stage I EOC. A significant increase in IL-8 and GROα was found in serum, but not until stage I and stage III EOC. In early stage disease, inflammatory markers are still confined to ovarian cystic fluid, but in later stage the cytokines are secreted into the blood. Although the potential biomarkers, MCP-1, IL-8, and GROα are known to be of importance in the carcinogenesis of ovarian cancer, they did not improve on CA125 in early diagnosis.We conclude that the ovarian cyst fluid, which is in direct contact with the primary tumor, is an excellent source to use in the search for an early EOC biomarker. Five to hundredfold higher concentration of MCP-1, IL-8, and GRO


Objective: although numerous studies have reported the association between birth season and sex ratio, few studies have been conducted in subtropical regions in a non-Western setting. The present study assessed the effects of pregnancy season on birth sex ratio in China. Methods: We conducted a national population-based retrospective study from 2006–2008 with 3175 children-parents pairs enrolled in the Northeast regions of China. Demographics and data relating to pregnancy and birth were collected and analyzed. A multiple logistical regression model was fitted to estimate the regression coefficient and 95% confidence interval (CI) of refractive error for mother pregnancy season, adjusting for potential confounders. Results: After adjusting for parental age (cut-off point was 30 years), region, nationality, mother education level, and mother miscarriage history, there is a significant statistical different mother pregnancy season on birth-sex. Compared with mothers who were pregnant in spring, those pregnant in summer or winter had a high probability of delivering girls (p < 0.05). The birth-sex ratio varied with months. Conclusions: Our results suggested that mothers pregnant in summer and winter were more likely to deliver girls, compared with those pregnant in spring. Pregnancy season may play an important role in the birth-sex. To our knowledge, no study has been conducted using a population-based cohort design to address the pregnancy season’s effect on the birth-sex. Hence, the pregnancy season-related effects on human birth-sex ratio thus remain poorly known and controversial. For example, Melnikov n winter , while Jn winter .We tested the null hypothesis that there is no seasonal variation in birth-sex in the Northeast regions of China. We examined the association between pregnancy season and birth-sex ratio. Here, we use a simple epidemiological model to reveal multiannual predictability based on high-quality birth data for China, which has a population around 1.4 billion.This research was designed to evaluate whether the season of pregnancy is associated with birth sex ratio in Inner Mongolia. To calculate the birth sex ratio accurately, the research area should be at least cover a population of 300,000, with a 10 per 1000 birth rate. A sample size of more than 3000 in one area can produce enough power to calculate a correct birth sex ratio. According to the administration areas in China, we used a multiple sage, randomizing and cluster sampling method to select Tongliao city in Inner Mongolia as a research field where Kerqin district, Baokang town and Shebaitu countryside were selected as study fields to represent city, county (or town) and rural population. Those selected areas, all children were investigated. Trained investigators collected and recorded the data with a standard questionnaire by using a face to face inquiry method. Data included was: (1) demographic characteristics; (2) any history of abortion and the medical history of the children’s mother, and in her pregnancy period; (3) delivery records. We recruited 3175 children-parents pairs. Two cases were missing data. We also excluded those not with abnormal birth dates, e.g., premature births. Finally, 3051 children who were born between 1 January 2006 to 31 November 2008 and their parents were investigated.SAS for Windows Statistical Software Package Version 8.2  was used for data processing and analysis. Birth-sex were analyzed as binary outcome variables and season of pregnancy was investigated as categorical variable, respectively. The seasons were categorized as spring , summer , fall , and winter  ,10,11. SF13,3037 = 1.94; p = 0.02). p < 0.05), than those pregnant in spring. The birth-sex ratio varied with months , and 1469 girls (48.2%). h months .et al. examined the association between reconstructed annual mean temperatures and annual offspring sex ratio at birth in the eighteenth to nineteenth century Sami from northern Finland. Their results showed that warm years correlated with a male-biased sex ratio, whereas a warm previous year skewed sex ratio towards females. The net effect of one degree Celsius increase in mean temperature during these two years corresponded to approximately 1% more sons born annually [Salmonidae) [Our results show that mothers who were pregnant in summer or winter are more likely to deliver girls than boys, compared with those pregnant in spring. Our results were partly aligned with previous studies and confirmed that there is a seasonality variation of birth-sex ratio . Helle eannually . Howeverannually . The eviannually , or turtannually  show thaannually , graylinmonidae) , floundemonidae) , and seamonidae) . Althougmonidae) , which pmonidae) , FoxL2, monidae) .et al.’s study, showing that temperature-dependent physiological mechanism(s) may override maternal ability to facultatively adjust offspring sex, and thus produce neutral or even maladaptive sex ratio variation.Additionally, other season related climatic factors might also be associated with off-springs’ birth-sex. Evidence from mammals indicates that other climatic factors such as greater evaporation also influence the second sex ratio in dairy cattle . AnotherOur study has special implications for public health considering global climate change which eventually could results in season changes, e.g., extension of the more extreme weather seasons. Thus could be a potential risk factor for the birth ratio structure. Studies with a larger sample size and different setting are thus warranted.First, the temperature used in the study was a monthly average, which cannot reflect daily variations. Second, due to a lack of accurate sex-determination time in pregnancy, the results might be inaccurate. However, the factors such as the seasonal climatic factors are quite similar and steady, especially since we used the monthly average temperature in the study. Third, children born early or later than 40 weeks can affect the results, although our large sample size could compensate for this. Fourth, local residents could be born in other areas, although our study’s participants are from a small city/town where the population is very steady.Our results suggested that mothers pregnant in summer or winter were more likely to deliver girls than those pregnant in spring. Pregnancy season may play an important role in the birth-sex.


This study was aimed to see the beneficial effect of butylated hydroxytoluene (BHT) as a semen additive of Hariana bull semen.The study was carried out in Hariana bulls. Twenty-four ejaculates from two bulls were used for this study. Each ejaculate was extended with standard glycerolated egg yolk tris extender and supplemented with BHT at two concentrations as 0.5 mM (T1) and 1.0 mM (T2). After dilution, equilibration and 24 h of cryopreservation, the samples were analyzed for progressive motility, sperm viability and membrane integrity.Progressive motility, sperm viability and sperm membrane integrity were significantly (p<0.05) increased in the samples fortified with BHT as compared to the control during the process of cryopreservation and thawing. The BHT concentration of 1 mM revealed better results as compared to 0.5 mM.Addition of 1.0 mM BHT was found better in cryopreservation of Hariana bull semen compared to 0.5 mM BHT and control samples. The addition of BHT has improved the sperm quality by acting as an antioxidant thereby reducing the lipid peroxidation of the sperms. Cryopreservation of sperm is the integral part of a successful artificial insemination program, which not only depends on the prefreeze sperm features, but also by the freezing protocols . CryopreFree radical generation is a major limitation during the process of sperm cryopreservation, which is generated from the non-viable sperms as well as from the extenders, which contain the molecular oxygen . The freButylated hydroxytoluene (BHT) is a phenolic antioxidant being supplemented in the semen extender as a measure to prevent the membrane permeability changes in the sperms during cryopreservation . BHT alsAntioxidant addition has been emerged as one of the most powerful way to overcome the excessive generation of free radicals during the time of semen cryopreservation and hence most of the laboratories are involved extending the semen with antioxidants. We have already studied the beneficial effects of Vitamin E, Vitamin C and various proteins which provide cryo-protection to the sperms during freeze-thaw process (data unpublished), however, literature is scanty regarding the incorporation of BHT in semen extender, as an antioxidant to protect sperm cells during cryopreservation. This provided us an open area to design our study to observe the effect of BHT addition in the semen extenders for its antioxidant effect reflecting protection to sperm cells.No ethical permission was required to conduct the study as the method of semen collection was noninvasive. However semen collection was done as per standard collection method without harming animal.The present study was conducted on Hariana bulls of the age group between 5.5 and 6.5 years and weighing between 450 and 500 kg body weight, reared at the University Instructional Livestock Farm Complex, College of Veterinary Sciences, U.P. Pandit Deen Dayal Upadhayaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura which is situated in a semiarid zone of Northern part of India, in the state of Uttar Pradesh. The bulls were fed 21.15 kg of greens, 4.83 kg of concentrate including service ration and 4.95-5.77 kg of wheat straw per bull per day. Bulls were apparently free of infection and were undergone for regular vaccination as per the prescribed manual of certified semen laboratory.A biweekly semen collection schedule was followed during the entire period of the study, which was carried out during January to March of year 2014. Semen was collected directly into a clean dry graduated centrifuge tube attached to the latex cone of the AV. Immediately after collection, tube containing semen were marked, transferred to the laboratory and placed in the water bath at 32-34°C for physico-morphological studies.viz. (i) after dilution with the extender, (ii) after equilibration(at 4-5°C for 4 h) and (iii) after 24 h of cryopreservation. Seminal attributes viz. progressive motility, sperm viability and membrane integrity (hypoosmotic swelling test [HOST]) were evaluated at all three stages.The collected semen was evaluated  and those which fulfill the criteria for cryopreservation were extended with glycerolated egg yolk tris (GEYT) extender with two different concentrations (0.5 and 1.0 mM) of BHT. Three stages of sperm evaluation were carried out 275.44 mg of BHT, Kosher grade  was dissolved in 25 ml of ethanol making a BHT concentration of 0.05 M. This solution was then added @ of 0.05 and 0.1ml in the two glass test tubes. Ethanol containing BHT was then evaporated at 37°C in an incubator resulting in sticking of BHT in the inner wall of the test tubes. The semen was extended with GEYT extender up to 80 million spermatozoa/ml. To each of this test tube 5 ml of extended semen was added making a concentration of 0.5 mM BHT (T1) and 1.0 mM BHT (T2). The extended semen along with BHT was then kept at 37°C for 5 min to allow uptake of BHT by spermatozoa. Simultaneously, the same amount of extended semen was added to another test tube (without BHT), which was considered as control group. All the extended semen (with and without BHT) were then filled in 0.25 ml, French straw with the help of filling and sealing machine, equilibrated in a cooling cabinet (temperature 4-5°C) in a straw rack for 4 h.The extended semen with BHT concentration of 0 mM, 0.5 mM and 1.0 mM were considered as control, treatment group T1 and T2 respectively and were taken for cryopreservation using a biological freezer (liquid nitrogen vapor freezing). These samples containing the BHT were processed for cryopreservation as per the standard protocol  developed in the semen biology laboratory, DUVASU, Mathura.viz. progressive motility, sperm viability and sperm membrane integrity (HOST) in the control and test samples (T1 and T2) [After 24 h of cryopreservation, the straws containing the semen were thawed in thawing unit  maintained at 37°C with holding time kept as 45 s. After thawing the straws were processed for retrieval of the sperms which was followed by physico-morphological evaluation  and T2) . Progres and T2) .® Version 22.0 for Windows®, SPSS Inc., Chicago, USA). Data are presented as mean and their standard error (Mean±standard error of mean). Effect of different inclusion levels of BHT (antioxidant) were analyzed using one-way analysis of variance and significance was tested at 5% level (p<0.05). Duncan’s multiple range test was used to compare the treatment means for various sperm attributes.Statistical analyses were performed using Statistical Package for Social Science  during three stages of sperm processing. Sperm viability exhibited significant (p<0.05) difference between control and two treatment groups. Group T2 exhibited the best results in terms of sperm viability . A simil during tviz. extended semen, semen after equilibration and thawing after 24 h of cryopreservation. The results obtained from the study have been presented in Tables The present study was an attempt to evaluate the beneficial roles of BHT as an antioxidant additive to the semen samples collected from Hariana bulls during three stages of semen processing Viability of the sperms after the process of freeze-thaw is always a challenging step as 30 to 40% of the reduction in the viability of the sperm is seen. The loss in the sperm viability has been associated with the changes in the temperature, and ultra-low temperature maintained during cryopreservation . The viaFree radicals generated at homeostatic levels are significant in regulating the sperm physiological functions like sperm capacitation, acrosome reaction, hyperactivation and sperm-oocyte fusion . HoweverSemen processing during the time of cryopreservation results in dilution of sperm antioxidant system and along with this, the generated free radicals brings damage to the polyunsaturated fatty acids present on the sperm cell membrane . The addStudies in many species of domestic animals have also been shown that BHT exerts a protective effect on the sperms during freeze-thaw process. The beneficial effects of BHT are also dependent on the concentration in the extender, which is also species dependent and specific. Earlier studies have reported the beneficial role of BHT is dependent on BHT concentration, sperm membrane composition, time for incubation and the type of extender used for the process of cryopreservation .Extension of the semen with desired low concentration of BHT is the prerequisite to get the best results in terms of sperm protection. Bull semen extended with 0.5-1 mM BHT has been shown better results as compared to 3 mM or more. Supplementation with higher concentrations of BHT has shown detrimental effects on the sperms opted for cryopreservation. In our study, we reported the similar concentration of BHT offering a protective effect on the sperm after freezing and thawing. BHT concentration has also exhibited a species specific variation -21.Progressive motility serves as the index of fertilization and serves as the most significant determinant of the sperm capability for bringing out fertilization. Motility is a complex factor, which is regulated strictly by the flagellar assembly proteins along with the generated ATP by the mitochondria . Sperm mSperm membrane integrity is the index of sperm function as well as an indication of metabolic status. Membrane integrity is associated with keeping the sperms active in terms of regulation of the osmotic balance of the cells. The loss in the membrane permeability is a common limitation in the sperms opted for freezing and thawing . MembranFor all the parameters consider under this study, BHT used to a level of 1.0 mM BHT (T2) did not have any toxic effect to the spermatozoa. Hence, our result indicates that 1.0 mM BHT is suitable for freezing bull spermatozoa in GEYT extender having 20% egg yolk and 7% glycerol with 80 millions/ml sperm concentration of extended semen.Extension of the semen with two concentrations of BHT improved the post-thaw motility, viability and membrane integrity of Hariana bull sperms. The exact mechanism behind the process of improvement of sperm quality after the addition of BHT has not been understood from the study, but it was probably due to the action of BHT as an antioxidant and a consequence reduction in the lipid peroxidation ,23. PolyThe present study investigated whether the addition of BHT has improved the quality of Hariana bull sperm after dilution, equilibration, and thawing. The results revealed a significant improvement in the quality of sperm in all the three stages with the addition of 1 mM BHT. The characters evaluated were progressive motility, sperm viability and membrane integrity. The findings of the study revealed a significant improvement in the sperm quality with the addition of both the concentrations of 0.5 mM and 1 mM BHT.Extender containing the exogenous BHT revealed better post-thaw semen quality as compared to the extender without BHT. Addition of BHT at a concentration of 1mM revealed better results as compared to 0.5 mM. BHT augmented post-thaw semen quality by the reduction in the generation of free radicals and thereby a consequent reduction in lipid peroxidation. Further studies are required to understand the role of BHT in improving the sperm quality and whether, this addition translates into the improved fertility of artificially inseminated sperms.AP was the MVSc. Scholar of the department who carried out experimental research work and laboratory analysis of data. AS was guide of AP, under whose supervision the thesis was submitted. AS planned and designed the experiment. AK helped in design of experiment. DKS help in manuscript preparation. DY, SSY and AK (MVSc. Scholars) helped in sterilization of equipment used in semen experiment, preparation of semen extender/stains for semen evaluation and processing of semen during the research work. All authors read and approved the final manuscript.


Schizophrenia is a complex mental disorder caused by an interplay between genetic and environmental factors, including early postnatal stressors. To explore this issue, we use two rat lines, apomorphine-susceptible (APO-SUS) rats that display schizophrenia-relevant features and their phenotypic counterpart, apomorphine-unsusceptible (APO-UNSUS) rats. These rat lines differ not only in their gnawing response to apomorphine, but also in their behavioral response to novelty . In this study, we examined the effects of early postnatal cross-fostering on maternal care and on the phenotypes of the cross-fostered APO-SUS and APO-UNSUS animals later in life. Cross-fostered APO-UNSUS animals showed decreased body weights as pups and decreased novelty-induced locomotor activity as adults , in accordance with the less appropriate maternal care provided by APO-SUS vs. their own APO-UNSUS mothers . In contrast, cross-fostered APO-SUS animals showed increased body weights as pups and reduced apomorphine-induced gnawing later in life , in line with the more appropriate maternal care provided by APO-UNSUS relative to their own APO-SUS mothers . Furthermore, we found that, in addition to arched-back nursing, non-arched-back nursing was an important feature of maternal care, and that cross-fostering APO-SUS mothers, but not cross-fostering APO-UNSUS mothers, displayed increased apomorphine-induced gnawing. Thus, cross-fostering not only causes early postnatal stress shaping the phenotypes of the cross-fostered animals later in life, but also affects the phenotypes of the cross-fostering mothers. Schizophrenia is a severe and complex mental illness with a neurodevelopmental origin. It affects approximately 1% of the general population Insel, , and is In order to investigate the interplay between genetic factors and postnatal stressors, we have used the apomorphine-susceptible (APO-SUS) rat line and their phenotypic counterpart, the apomorphine-unsusceptible (APO-UNSUS) rat line  with wood chip bedding located in temperature and humidity controlled rooms with a standard 12 h light/dark cycle (lights on from 07:00 h to 19:00 h).All experiments were performed in accordance with institutional, national and international laws and guidelines for animal care and welfare and the experiments were approved by the Radboud University Nijmegen Ethical Committee on Animal Experimentation (RU-DEC). Rats were bred in the Central Animal Laboratory of the University of Nijmegen according to methods described by Cools et al. . BrieflyOne male and one female rat were placed for one night together in a special mating cage containing a wire-mesh floor. The next morning this cage was checked for a copulation plug. When the plug was found, that day was labeled embryonic day (E) 0. The pregnant females were housed in isolation and the cages were cleaned at E15 with great care to avoid stress. From E19 onwards, cages of pregnant rats were checked three times a day  for the presence of pups. The day mothers gave birth to the first pup of their nest (E22 ± 0.03) was labeled postnatal day (PND)0. Nests which were born after 16:00 h were considered born at 08:00 h on the following day. Cages were again cleaned at PND14 and PND21 by only renewing the dirty bedding outside the nest. Pups were weaned at PND28, after which they were housed with one or two other rats of the same sex and nest. The breeding animals were housed together with one or two other rats of the same rat line and sex.n = 113; APO-UNSUS: average = 10.8 ± 0.26 pups, n = 124). Extreme APO-SUS and APO-UNSUS nests  were excluded from the experiment.In the un-/cross-fostering experiment, at 16:00 h the dams were removed from their cages for a short period of time (5 min.) and were put back with their own pups (unfostered) or with pups from their phenotypic counterpart (cross-fostered)  and the cross-fostering and unfostering mothers (at ~2 weeks after weaning) were subjected to an open field test and the apomorphine susceptibility test. For the open field experiment, rats were placed in the middle of a square black table  surrounded by a white background illuminated by white light of 80 Lux at the middle of the open field  = −6.3, p < 0.05) and weight at PND28 (t(134) = 2.5, p < 0.05) significantly differed between control males and females, the results regarding these two measures were analyzed per gender  and treatment (cross-fostered and unfostered), followed by thood  = 36.7, p < 0.05), arched-back nursing  = 4.89, p < 0.05), the frequency of the mother away from the nest  = 12.37, p < 0.05) and the self-grooming frequency of the mother  = 12.94, p < 0.05). In addition, cross-fostering differentially affected the weights of the APO-SUS and APO-UNSUS pups  = 33.47, p < 0.05, females F = 7.61, p < 0.05). Rat-type-specific effects of the cross-fostering were also found at adulthood  = 5.16, p < 0.05). The results of the post hoc analyses are described below.APO-SUS- and APO-UNSUS-specific effects of cross-fostering were found for all measures of maternal care (except for licking of the pups). A two-way ANOVA revealed significant rat type × treatment interactions for non-arched-back nursing (t(22) = −5.2, p < 0.05, Figure t(22) = 4.4, p < 0.05, Figure t(22) = 1.2, n.s., Figure t(22) = 1.2, n.s., Figure t(22) = 0.5, n.s, data not shown) were not different between cross-fostered and unfostered APO-SUS nests. In contrast, cross-fostered APO-UNSUS pups received significantly less non-arched-back nursing (t(18) = 3.6, p < 0.05, Figure t(18) = 0.8, n.s, Figure t(18) = −3.9, p < 0.05, Figure t(18) = −3.3, p < 0.05, Figure t(18) = 0.1, p < 0.05, data not shown).Cross-fostered APO-SUS pups received significantly more non-arched-back nursing (t(67) = 2.7, p < 0.05, correlation with nest size p < 0.05 ; female: t(64) = 6.3, p < 0.05, correlation with nest size p < 0.05 . Cross-fostered APO-SUS pups weighed significantly more than unfostered APO-SUS pups at PND28  = 4.2, p < 0.05, Figure t(87) = 2.5, p < 0.05, Figure t(73) = −4.6, p < 0.05, Figure t(84) = −1.5, n.s., Figure As previously shown  = −2.0, p < 0.05, Figure t(93) = −0.83, n.s., Figure t(88) = −2.1, p < 0.05, Figure t(97) = −1.4, n.s., Figure t(99) = −0.17, n.s., Figure t(78) = −1.1, n.s., Figure Cross-fostered APO-SUS pups showed a decreased apomorphine-induced gnawing score at adult age compared to unfostered APO-SUS animals (t(21) = 2.4, p < 0.05, Figure t(17) = 0.2, n.s., Figure t(16) = −1.1, n.s.; APO-UNSUS mothers: t(16) = −0.4, n.s., data not shown).Two weeks after the mothers were separated from their pups, APO-SUS mothers having fostered APO-UNSUS pups showed a significant increase in apomorphine-induced gnawing when compared to APO-SUS mothers that had fostered their own pups  is due to the exposure to pups of a different phenotype, resulting in a stronger and longer-lasting stress response in APO-SUS than APO-UNSUS mothers (see also Rots et al., Although most mother-pup interaction studies have focused on the role of arched-back nursing (Caldji et al., The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Low birth weight (LBW) remains to be a leading cause of neonatal death and a major contributor to infant and under-five mortality. Its prevalence has not declined in the last decade in sub-Saharan Africa (SSA) and Asia. Some individual level factors have been identified as risk factors for LBW but knowledge is limited on contextual risk factors for LBW especially in SSA.Contextual risk factors for LBW in Ghana were identified by performing multivariable multilevel logistic regression analysis of 6,900 mothers dwelling in 412 communities that participated in the 2003 and 2008 Demographic and Health Surveys in Ghana.Contextual-level factors were significantly associated with LBW: Being a rural dweller increased the likelihood of having a LBW infant by 43%  while living in poverty-concentrated communities increased the risk of having a LBW infant twofold . In neighbourhoods with a high coverage of safe water supply the odds of having a LBW infant reduced by 28% .This study showed contextual risk factors to have independent effects on the prevalence of LBW infants. Being a rural dweller, living in a community with a high concentration of poverty and a low coverage of safe water supply were found to increase the prevalence of LBW infants. Implementing appropriate community-based intervention programmes will likely reduce the occurrence of LBW infants. Deliveries in low and middle income countries are often complicated by adverse birth outcomes such as stillbirth, early neonatal mortality and morbidity. Low birth weight (LBW) remains to be a leading cause of neonatal death th percentile for the appropriate gestational age Infants can have LBW either as a result of small-for-gestational-age (SGA) or preterm delivery. An infant is said to be small-for-gestational-age when the gender-specific birth weight is below the 10Globally, one out of seven infants is born with LBW. The incidence has not declined in the last decade in Sub-Saharan Africa (SSA) and Asia However, despite these numerous identified individual-level risk factors for LBW, there is a wide gap in epidemiological knowledge regarding the common effect that the community context has on the incidence of LBW especially in SSA. Studies conducted outside SSA have identified the impact of residential segregation This is a population-based study that utilized a combined dataset of the 2003 and 2008 Ghana Demographic and Health Survey (GHDS) to identify contextual risk factors for LBW in Ghana.Comprehensive information on the sampling techniques and procedures for the GDHS data collection have been published elsewhere Mothers were asked to recall the birth weight of their infants or provide hospital cards to confirm it. In case they could neither recall the birth weight of their infants nor provide a hospital card, they were asked whether the birth weight of their babies was very big, bigger than average, average, smaller than average or very small. For the purpose of the current analysis we classified infants with a birth weight smaller than average and very small as LBW infants We referred to the primary sampling unit (PSU) of the DHS data as a community. The impact of the community context on low birth weight was examined by considering place of residence , proportion of the community that were having access to healthcare and safe water coverage, and proportion of illiterate (those that can neither read nor write in any language) and those living in extreme poverty in the community (estimated asset index <20% poorest quintile) as contextual factors.Un-confounded effects of contextual risk factors on LBW were estimated after considering potential confounders based on epidemiological knowledge, prior studies, and the available information in the GDHS. Maternal age, parity, birth interval, unplanned pregnancy, ethnicity, anaemia in pregnancy, use of antenatal care, use of antimalarial or mosquito nets during pregnancy, smoking, body mass index, maternal education, occupation, wealth status and marital status were considered as potential confounders in the analysis. Marital status was classified as currently, formerly and never married. Maternal educational attainment was categorized into no education, primary, and secondary or higher education. The GDHS applied an asset-based approach to estimate household wealth status In the descriptive analyses, the characteristics of the study population were expressed in terms of numbers and percentages. The prevalences of LBW across the categories of the explanatory variables were estimated in terms of numbers and percentages.We applied a two-level multivariable multilevel logistic regression analysis, fitting three models different models. Model 1 (empty or null model) has no explanatory variable and we used it to decompose the total variance of LBW between the contextual and individual level. Model 2 contained the contextual-level factors and we extended this model to form model 3 by accommodating all the potential confounders . Sensitivity analysis was conducted to assess whether the results of the analyses were consistent with the group of LBW infants classified to be of very small birth weight. This was necessitated by the potential risk of having a misclassified outcome by maternal self-report.Measures of association between the contextual risk factors and LBW were reported in terms of odds ratios (OR) with their P-values and 95% confidence interval (CI) after considering potential confounders.Random effects were expressed in terms of Area variance (AV), Median Odds Ratio (MOR) and Intra-Cluster Correlation (ICC)/Variance Partition Coefficient (VPC).The fitness of the model was assessed using Akaike Information Criterion (AIC) while Variance Inflation Factor(VIF) was used to check for multicollinarity in the model. Two-tailed Wald test at significance level of alpha equal to 5% was used to determine the statistical significance of the determinants and all the analyses were performed with StataSE 11 software package, StataCorp LP, Texas, United States.Ethical clearance to conduct GDHS was obtained from the Ethics Review Committee, Ghana Health Service, Accra, Ghana and the Ethics Committee of ICF Macro in Calverton, United States. GDHS data are public access data and were made available to us upon request by Measure DHS.The results of the multivariable multilevel logistic regression (MMLR) are shown in After extending Model 1 to form Model 2 by entering the contextual risk factors, AV , MOR 1.51 (95% CI 1.38–1.70) and ICC (0.055) remained significant but reduced because part of the contextual-level variance was explained by the contextual risk factors in the model. The estimated proportional change in variance (PCV) was −8.7%, indicating that 8.7% of the contextual-level variance was explained by the contextual risk factors entered into the model. Further, in order to estimate an un-confounded effect of the contextual risk factors, we adjusted for the potential confounders  in Model 3. The AV , MOR 1.47 (95% CI 1.27–1.70) and ICC (0.048) remained significant but reduced and the PCV was −12.1%, meaning that 12.1% of the contextual-level variance of LBW can be explained by the compositional characteristics of mothers dwelling in the communities. About 4.8% of the total variance of LBW that can be attributed to the contextual-level factors remained significant even after considering some contextual risk factors for LBW.The contextual risk factors for LBW that remained significant after adjusting for the potential confounders  are shown in There were progressive reductions in AIC from Model 1 to 3, indicating that the explanatory value of the model increases from Model 1 to 3. In other words Model 3 explained the determinants better than Model 1 and 2.To assess the potential effect of misclassification of low birth weight on the association observed between contextual-level factors and low birth weight we limited our analyses to the infants considered to be of very small birth weight (VLBW). Area variance was observed to increase and remained significant , the intra-cluster correlation (ICC 0.140) and median odds ratio  also increased. The odds of having a VLBW infant increased four-fold  among mothers living in communities with a high concentration of extreme poverty while mothers living in communities with a high coverage of safe water supply reduced their likelihood of having a LBW infants by 46%  compared to their counterparts dwelling in areas with a low coverage of safe water supply. However the statistical significant effect of place of residence on LBW was deattenuated .This study investigated LBW beyond the traditional method of examining the risk factors for LBW by estimating the association between the context of the community where the mothers were residing, and the prevalence of LBW after controlling for individual characteristics of the mothers. The study showed contextual factors to be significantly associated with LBW. Being a rural dweller increased the likelihood of having a LBW infant and the plausible explanation for this is that living in rural areas in SSA simply means residing in a deprived community in terms of job opportunities, social amenities and infrastructures which carries an increased risk of LBW. This finding is consistent with a previous study conducted in the United States that found that mothers residing in urban areas tend to be protected from having a LBW infant Further, residing in wealthier communities was observed to protect women from having LBW infants compared to their counterparts dwelling in neighbourhoods with a high concentration of extreme poverty. Dwelling in such contexts might lead to maternal psychosocial stress which in turn has been implicated to increase the release of catecholamine and cortisol, and subsequent stimulate the release of corticotrophin releasing hormone (CRH) through cortisol. The release of CRH has been hypothesized to initiate the onset of labour Considering the outcomes of this study, implementation of community-based intervention programs that can bridge the gaps between the rural and urban settlements in terms of infrastructural development are considered to be necessary. In the absence of any intervention, poverty can become an inter-generational problem that may be difficult to address. Thus, both government and non-governmental organizations will need to be more proactive towards implementing sustainable population-based poverty eradication programs coupled with women and youth empowerment programs. Provision of regular safe water supply to the communities will likely reduce the occurrence of LBW. Impact of such programs will go beyond individual-level, population will be its unit of manifestation. It is important to note that 4.8% of the variance in LBW in Ghana that was attributed to contextual factors remained significant even after considering contextual-level factors indicating why it is important for future studies to identify other contextual risk factors for LBW.As we used nationally representative data with excellent individual and household response rates for this study, study findings can easily be generalized for Ghana and beyond. Likewise the application of multilevel analysis in this study, made it possible to disentangle the effects of the individual and contextual factors on LBW. To the best of our knowledge, none of the previous multilevel studies on LBW accounted for haemoglobin concentration status and the desire to be pregnant unlike our study where these factors and other known potential confounders were considered.However, limitations of this study cannot be overlooked. Alcohol intake was not captured in the GDHS so it was not included as a potential confounder but we believe this will not have any significant impact on the observed contextual effects because smoking and alcohol intake among women in Ghana is rare; for instance this study found that the prevalence of smoking among mothers was 0.1%. Because we examined secondary cross-sectional data, we were unable to evaluate the effect of the duration of living in a poverty-concentrated community on LBW. This study did not examine for possible cross-level interaction effect, thus we suggest that subsequent study should explore this area.Mothers that neither had any evidence to confirm the birth weight of their children nor were able to recollect the birth weight were asked to specify whether the birth weight of their children was very big, bigger than average, average, smaller than average or very small. We considered smaller than average and very small as LBW in our analysis. Every mother was given the opportunity to specify the birth weight of their baby thus missing data is not an issue in this variable. The main challenge here is the possibility of misclassifying birth weight by mothers that could not provide the birth weight of their children due to their inability to remember the birth weight or the birth weight was not measured at birth; this is different from recall bias. Thus misclassification of birth weight could have occurred, however previous results from demographic and health survey data from Cambodia, Kazakhstan and Malawi assessing whether mother's perception of a baby's birth weight is a good proxy for birth weight noted good agreement between mother's perception of a baby's birth weight and measured birth weight Further based on logical reasoning out of the five classes of birth weight  the possibility of misclassifying infants with normal birth weight as low birth weight should be minimal among infants classified as “very small infants”. Indeed, the observed difference in the prevalence of “very small infant” among infants that their birth weight was provided and those that were assessed based on mother's perception of a baby's size at birth was less than 1.8%. We thus, examined whether the contextual effects observed remained significant in the subgroup of infants classified to be very small, i.e. very low birth weight (VLBW). The random effect of the community context increased  Likewise the effect of poverty  and safe water coverage  were more pronounced when VLBW infants were considered; reaffirming the importance of these contextual level factors on the occurrence of LBW.This study has demonstrated that contextual risk factors have independent effects on the prevalence of LBW infants in Ghanaian communities regardless of individual-level characteristics of the mothers. Being a rural dweller, Living in a community with a high concentration of poverty and a low coverage of safe water supply were found to be associated with a high prevalence LBW while poverty and poor coverage of safe water showed a pronounced impact on the prevalence of VLBW. Implementing community-based intervention programs that will address poverty alleviation, provision of regular safe water supply and the infrastructural development of rural communities will likely reduce the occurrence of LWB.