Anthropometry is a universally applicable, non-expensive, rapid and noninvasive technique used to evaluate and reflect the nutritional status of an individual. Anthropometric measurements of newborns reflect their general health, nutritional status and future survival by tracking trends in growth and development over time. It has also considerable significance in terms of determining the risk of death and extra uterine complications. Most previously conducted studies assessing newborn anthropometry had used birth weight as the sole parameter. But it is apparent that other anthropometric measurements, such as length and head circumference, are also important in predicting short-term and long-term outcomes. So this study assesses anthropometric measurements of singleton live full-term newborns at University of Gondar comprehensive specialised hospital, Ethiopia.Hospital-based cross-sectional study was conducted among 333 newborn from 5 June to 11 July 2022, in the maternity and neonatal ward of University of Gondar comprehensive specialised hospital. A systematic random sampling technique was employed to select the study participants. The Kobo toolbox software platform was used for data collection, and STATA software version 16 was used for analysis.The mean birth weight, length and head circumference of the newborns in the current study were 2977 grams , 47.05 centimeters (95% CI: 46.72–47.37) and 34.7 centimeters , respectively. The prevalence of SGA (< 10th percentile) and LGA (> 90th percentile) was 20.12% and 6.01%, respectively. Independent samples t-test was done to see the association of newborn sex with anthropometric indices, and the result showed that the difference was statistically insignificant in all of anthropometric parameters.This study of normal reference values will provide basic step for future standardisation of Ethiopian term newborns anthropometric parameters to be used for accurate assessment of newborns. Anthropos, “man” and metron, “measurement”) to understand human physical variation in various attempts to correlate physical with racial and psychological traits  and newborn anthropometric indices . As a result, clear associations between maternal and newborn anthropometric parameters were observed.r < 0.5) were found in newborn birth weight with maternal weight, MUAC, and LBM with a Pearson correlation coefficient (r) of 0.36, 0.37 and 0.36, respectively. Maternal height and BMI had also a weak positive correlation with birth weight. The newborn length has a moderate positive correlation with maternal MUAC and LBM. In addition, maternal BMI, weight and height have also a weak positive correlation with newborn length. All of the maternal anthropometric parameters  has a statistically significant (p < 0.05), but weakly positive correlation (r < 0.3) with newborn HC , which may hamper the interpretation of the independent correlation.Moderately strong associations , 47.05 centimeters (95% CI: 46.72–47.37) and 34.7 centimeters , respectively.The mean birth weight in this study was observed to be lower than that of studies conducted in England (3272 gm.) , Turkey The mean term newborn length in this study was lower than that of studies conducted in England (50.8 cm) , Turkey However, our mean HC value was higher than studies conducted in Yemen 33.7 cm) , England3.7 cm , When comparing the mean values of the birth weight, HC, and length in our study with those from the WHO Multicenter Growth Reference Study (MGRS) , the difRegarding our mean HC value, it was greater than this international average. These findings of higher HC value in comparison with MGRS is supported by a study conducted in Ethiopia previously by Ephrem et al , in whicWhen comparing the mean values of the birth weight, HC and length in our study with those from the WHO Multicenter Growth Reference Study (MGRS) , the difRegarding our mean HC value, it was greater than this international average. These findings of higher HC value in comparison with MGRS is supported by a study conducted in Ethiopia previously by Ephrem et al , in whicThe means of newborn birth weight, HC and length in our study were comparable with Sudan, Egypt and Yemen but showed a significant variation when compared to different Western countries. This study of normal reference values will provide basic step for future standardisation of Ethiopian term newborns anthropometric parameters to be used for accurate assessment, development and maturity of newborn births that would lead to identify newborns at risk and help in better management.


The impact of small-for-gestational-age (SGA) on very-low-birth-weight (VLBW) premature infants remains inconclusive. This study aimed to assess the effects of being born SGA status on the short-term and long-term outcomes in VLBW preterm infants.We conducted a population-based, prospective cohort study on VLBW preterm infants born in Taiwan between 2012 and 2017. Sociodemographic, neonatal, growth and neurological data at 2 years of corrected age were collected. A total of 4243 VLBW infants born at 24 through 32 completed weeks' gestation participated in this study, of whom 1,005 had SGA status defined as a birth weight <10th percentile of gestation, and 3,238 did not (the non-SGA group).We compared the risks of short-term outcomes , long-term outcomes . Subgroup analysis was performed by stratification of gestation age (GA): GA 24–26, 27–29 and 30–32 weeks.p < 0.05). The SGA group had a significantly increased risk of bronchopulmonary dysplasia in GA 27–29 and 30–32 weeks . We also found that there was an increased risk of severe retinopathy of prematurity in GA 24–26 and 27–29 weeks in the SGA group compared with the non-SGA group .In the analysis of short-term outcomes, the SGA group had an increased risk of neonatal mortality  in all GA subgroups in comparison with the non-SGA group (p < 0.05).In the analysis of long-term outcomes, the SGA group had a significantly increased risk of NDI throughout all GA subgroups  in comparison with the non-SGA group. The SGA groups also had an increased risk of growth status <10th percentile at 2 years of age (SGA VLBW premature infants had higher risks of neonatal death, growth status <10th percentile, and NDI at 2 years of corrected age compared with the non- SGA premature infants. Prenatal surveillance, postnatal attention, and long- term follow-up are warranted to improve the outcomes of VLBW SGA premature infants. The prevalence of preterm birth and VLBW preterm birth were 9.31% and 0.88% in Taiwan between 2012 and 2017, respectively . In neonPreviously, the two terms “intrauterine growth restriction (IUGR)” and “SGA” were used interchangeably –8. HowevThe etiologies of IUGR and SGA are diverse , 15. ToxHeterogeneity exists in growth and neurodevelopmental outcomes in SGA preterm infants compared to those in the non-SGA group. This is due to different definitions of SGA as well as inclusion criteria of the studies. Children born SGA were unable to have catch-up-growth ranging from 13 to 40% in different reports . Hokken-Because of countless prenatal, perinatal and postnatal variables, VLBW premature neonates born SGA are especially at risk of neurodevelopmental impairment (NDI) until later life , 23. ManThis study aimed to assess the effects of being born SGA status on short-term outcomes  and long-term outcomes (growth status <10th percentile and NDI at 2 years of corrected age) among VLBW preterm infants compared with the non-SGA VLBW premature infants.2.2.1.VLBW premature neonates born between 2012 and 2017 at 22 neonatal care centers were enrolled in the Taiwan Premature Infant Follow-up Network (TPFN) database. This database covers more than 70% of all tertiary medical centers which are capable of caring for VLBW preterm neonates in Taiwan. This prospective, longitudinal, multicenter cohort study evaluated VLBW premature neonates admitted to neonatal wards including intensive care units (NICUs) or newborn general wards within 1 week after birth until they survived to discharge. Sociodemographic, perinatal, and neonatal data during hospitalization were collected. The exclusion criteria were infants with major congenital anomalies or chromosomal disorders. SGA infants were defined as having a birth weight less than the 10th percentile for gestational age (GA) according to Taiwanese infants' sex-specific standards for singleton  or twinsThis study was approved by the Institutional Review Board of Mackey Memorial Hospital (IRB number 20MMHIS277e). All parents signed an informed consent form designed by the Premature Baby Foundation of Taiwan.Infants born with a GA of 24–32 weeks in the TPFN database who survived to discharge and completed follow-up to a corrected age of 2 years were enrolled into the final analysis. Among these participants, those who were SGA were compared with those who were non-SGA in neonatal and 2 years' neurological outcomes. Subgroup analysis was performed by stratifying the SGA and non-SGA groups in to three groups by GA: 24–26, 27–29 and 30–32 weeks. 2.2.Neonatal data, including the details of neonatal morbidities and management during NICU hospitalization, were recorded. Bronchopulmonary dysplasia (BPD) was defined as oxygen requirement at the postmenstrual age of 36 weeks. Severe intraventricular hemorrhage  was diagnosed using brain sonography. Cystic periventricular leukomalacia (cystic PVL) was detected by brain sonography or cranial magnetic resonance imaging (MRI) scan. Necrotizing enterocolitis (NEC) (≥Stage 2A) was defined according to modified Bell's criteria. Advanced retinopathy of prematurity (ROP) (≥Stage III or requiring laser or injection treatment) was classified according to international guidelines.2.3.All study participants were followed until a corrected age of 2 years in the TPFN. Growth status was assessed, including body weight (BW), body length (BL), and head circumference (HC); these parameters <10th percentile at 2 years of corrected age were defined as <10.5 kg, <83.9 cm, and <46.5 cm, respectively, in boys, and <9.9 kg, <82.3 cm, and <45.4 cm, respectively, in girls . Neurode2.4.All statistical analyses were conducted using R version 4.0.2 . Continuous data were presented as mean and SD, and categorical data were presented as numbers and proportions. Unadjusted comparisons between categorical variables were performed using the chi-square test, and continuous data were compared using the independent t-test. Multivariable logistic regression was used to estimate the relative risk of poor cognitive development in VLBW SGA infants compared with non-SGA preterm infants. Potential confounders including sex, use of prenatal steroids, preterm premature rupture of membranes, being the first-child, and paternal and maternal educational status less than 12 years were included in the model –39. Adju3.n = 5,679) were enrolled, of whom 29 died after discharge and 1,407 were lost to follow-up by a corrected age of 2 years. The remaining 4,243 VLBW infants completed the follow-up course (follow-up rate = 74.71%), of whom 1,005 (23.69%) had SGA status and 3,238 (76.31%) did not   .3.1.p < 0.001).Sociodemographic, perinatal, and neonatal data of the SGA and non-SGA groups were shown in 3.2.Subgroup analyses by GA  were performed to investigate the effects of SGA on the incidence of various neonatal outcomes . Multivap < 0.01). Although an increased risk of BPD was observed in all SGA subgroups, the risk was significantly higher only in the GA 27–29 and 30–32 subgroups . There were also increased risks in cystic PVL and NEC in all SGA subgroups, however none of them were statistically significant. An increased risk of severe ROP requiring treatment was observed in the SGA subgroups with GA at 24–26 and 27–29 weeks ; however, a non-adverse effect was observed in GA 30–32 weeks .The results showed that the SGA group was associated with an increased risk of death in all GA subgroups  compared with the non-SGA group (3.3.The incidence rates of binocular blindness were 0% (=0/78), 0% (=0/278), and 0.15% (=1/649) in the SGA subgroups , compared to 0.12% (=1/840), 0.06% , and 0% (=0/805) in the non-SGA subgroups.The incidences of hearing impairment requiring hearing aids or deafness were 5.13% (=4/78), 2.52% (=7/278), and 0.77% (=5/649) in the SGA subgroups , compared to 2.74% (=23/840), 1.95% , and 0.99% (=8/805) in the non-SGA subgroups.p < 0.001) (p < 0.05).Multivariable analyses were performed to explore the association between SGA and neurodevelopmental outcomes at 2 years of corrected age after adjusting for sex, use of prenatal steroids, preterm premature rupture of membranes, being the first-child, maternal education ≤12 years and paternal education ≤12 years according to the literature review. < 0.001) . SGA stap < 0.01).p < 0.05). Of note, that among SGA VLBW preterm infants, those at GA 24–26 weeks tended to have motor composite score (MCS) <85  and NDI . In addition, those at GA 30–32 weeks tended to have delays in development in multiple domains: cognitive composite score (CCS) <85 , MCS <85  and NDI .In the analysis of neurodevelopmental outcomes at 2 years of corrected age, the SGA group was associated with an increased risk of NDI in all GA subgroups . Although the SGA group had an increased risk of BPD in all GA subgroups, the risk was significantly higher only in the GA 27–29 and 30–32 subgroups , but not at GA 24–26 weeks (p = 0.57). Preterm neonates born at GA 24–26 weeks were relatively small and fragile and tended to have a higher risk of developing BPD. Our observation was that the BPD rates were both high in the SGA and non-SGA groups at GA 24–26 weeks (75.64% vs. 72.63%), so no statistical significance existed between the two groups (p = 0.54). Additionally, the nutritional status and degree of ventilator support could not be obtained in the TPFN database, and further large-scale surveys are warranted to evaluate the possible mechanisms.Bronchopulmonary dysplasia (BPD) is a neonatal lung problem with multifactorial etiologies, including possible pulmonary ontogenic changes at higher gestational ages related to nutrition or growth in animal model , 46, durSimilar to previous studies , 50, we p < 0.05), however there were non-adverse effects in GA 30–32 weeks   compared with the non-SGA subgroup  . This fi = 0.66) . The mec = 0.66) . Further4.2.Consistent with Itabashi et al.’s report , we demoOur results showed a significantly increased risk of NDI in the SGA subgroup after adjusting for confounding factors in all GA subgroups  –6. This Children born very preterm, especially before a GA of 32 weeks, are at particularly high risk of long-term disabilities because of various prenatal, perinatal, and neonatal factors . Male inp < 0.05). Higher rates of cystic PVL and NEC ≧ stage IIA were observed in all SGA subgroups, although the differences were not significant. We also found that all SGA subgroups had a significantly higher incidence of NDI at 2 years of corrected age compared with non-SGA subgroups. Moreover, the SGA group with a GA of 24–26 weeks had a higher rate of MCS <85 in BSID-III than the non-SGA group at 2 years of corrected age (p < 0.05). Furthermore, the SGA group with a GA of 30–32 weeks had CCS < 85, MCS <85 in BSID-III, and NDI at 2 years of corrected age (p < 0.05).To identify potential associations between neonatal morbidities and neurodevelopmental outcomes at 2 years of corrected age between the SGA and non-SGA groups, we performed a subgroup analysis according to GA at 24–26, 27–29 and 30–32 weeks. SGA VLBW preterm groups had a significantly higher rate of severe ROP ≧ stage3 or requiring treatment in both GA 24–26 and 27–29 weeks. SGA infants also had a higher incidence of BPD at GA 27–29 and 30–32 weeks , which may be associated with the higher risk of NDI in the SGA group. Further large-scale study in maternal pathology and neurodevelopmental outcomes in SGA neonates are warranted.Second, the increased neonatal morbidities resulting from SGA could have adverse effects on cognitive, motor, vision, hearing or overall NDI toward at least 2 years of age . Regev ep < 0.05). Severe ROP is strongly associated with blindness  in SGA preterm infants, especially the persistence of microcephaly reflecting cerebral volume at 2 years of corrected age, has been reported to determine poor intelligence and neurosensory or motor developmental outcomes , 60, 61.It has been proposed that brain maturation was related to retarded motor development in preterm neonates at GA < 28 weeks with severe SGA (Three possible explanations for these results are as follows:vere SGA . We founvere SGA .Our results differ from those of other reports , 26, 63,Our findings also have important public health implications. The higher risk of NDI in VLBW preterm neonates born SGA indicates that they may need more resources for rehabilitation including occupational, physical, and speech therapies. Additional attention may also be required when this vulnerable group enters school. This study suggests that government health agencies, including the Ministry of Health and Welfare, and the Bureau of National Health Insurance in Taiwan, should provide more resources to SGA VLBW preterm infants to improve their survival rate and neurodevelopmental outcomes. We also suggest that our government health agencies provide more supports for high-risk pregnant women with fetal growth restriction in their prenatal examinations, including Doppler sonographic examinations for umbilical blood flow to detect ADEV or REDV, biophysics, and fetal growth velocity, which provide very important information for the timing of delivery, either iatrogenic delivery or expectant management , 64.The strength of this study is the prospective, multicenter cohort design with the inclusion of 22 neonatal care centers, which covers approximately 70%–80% VLBW preterm neonates born in Taiwan. This is the first population-based cohort study on growth and neurodevelopmental outcomes at 2 years of corrected age in SGA VLBW preterm infants compared with non-SGA VLBW preterm infants in Taiwan. However, this study had some limitations. Although the TPFN database includes very detailed and complete perinatal and neonatal data, the incidence of SGA preterm birth in Taiwan could not be obtained by exploration in this study, and some obstetric sonographic parameters, such as symmetric or asymmetric IUGR status, placental blood flow and fetal cerebral blood flow patterns, were not available. Detailed obstetric sonogram data can help assess fetal growth restriction, which may predispose individuals to SGA.Another limitation of this study was the case distribution of the cohort. By definition, SGA is the 10th percentile by birthweight, which means it should make up about 10% of the general VLBW population. However, the TPFN databank was not a nationwide population, so the overall case number was not large enough to achieve normal distribution in each GA subgroup. Further large-scale population-based cohort study is warranted.5.This study provides important information for prenatal counseling as well as evidence of the public health impacts of SGA births. Our results showed a strong association between SGA birth status and neonatal mortality in VLBW premature infants born at GA of 24–32 weeks. Being born with SGA status was also associated with increased risks of BW, BL, and HC remaining less than the 10th percentile as well as NDI at 2 years of corrected age. Antenatal close surveillance, postnatal comprehensive care, and long-term follow-up are warranted to improve the outcomes of premature VLBW SGA infants.


To analyze the association between birth weight and bone mineral density (BMD) in adolescence. A birth cohort study in São Luís, Maranhão, using data from two moments: at birth and at 18–19 years. Exposure was the birth weight in grams, continuously analyzed. The outcome was BMD, using the Z-score index (whole body) measured by double X-ray densitometry (Dexa). A theoretical model was constructed in acyclic graphs to identify the minimum set of adjustment variables – household income, the mother knowing how to read and write at the time of birth, prenatal care, tobacco use during pregnancy, and parity — to evaluate the association between birth weight and bone mineral density in adolescence. Multiple linear regression was used in Stata 14.0 software. A 5% significance level was adopted. From 2,112 adolescents, 8.2% had low birth weight and 2.8% had a low BMD for their age. The mean full-body Z-score was 0.19 (± 1.00). The highest birth weight was directly and linearly associated with BMD values in adolescence , even after adjustment for the variables household income  and the mother knowing how to read and write . Although after adjusting the variables the association attenuated, birth weight positively and linearly relates to BMD in adolescence. BMD has been widely studied in adults and the older population, phases in which higher prevalence of osteoporosis and fractures resulting from bone mineral loss occur. However, the bone mineral density achieved in adulthood depends on the peak bone mass acquired up to 20 years old, which makes investigation in adolescents important. Authors believe that an early loss of BMD in adolescence may associate with some pathologies and/or unhealthy lifestyle .Bone mineral content (BMC) is the amount in kilograms of bone that, divided by its size, results in bone mineral density (BMD) in g/cm.Bone mineralization begins in intrauterine life and extends from childhood to early adulthood, but during childhood and adolescence occurs the greatest growth and development of bone mineral tissue.Early life factors, such as birth weight and intrauterine growth restriction, may influence bone mineral mass and the risk of osteoporosis.Bone health at different stages of life may reflect previous stages, although disagreements on how this process happens exist. Authors believe that insufficient fetal nutrition can lead to permanent changes in the development of the neuroendocrine system — insulin-like growth factor I and growth hormone, influencing bone development throughout life.In a Norwegian cohort study, newborns with low birth weight presented lower peaks of bone mass and higher frequency of osteoporosis, implying a higher risk of fracture in adulthood.A systematic review found that higher birth weight is determinant for better bone health, confirming that bone mass programming could exist. The effect may occur in children, but is inconclusive among adolescents. The effect of birth weight on bone mass among children was on BMD and BMCThe exploration in population-based longitudinal studies on the effect of early life variables and their determination on bone mineral density in adolescence is scarce. However, the study of BMD in younger individuals allows to know the early determinants of bone health, to assist in the planning of individual and collective interventions, reducing the effects of osteoporosis in adults and the older population.This study aims to analyze the association between birth weight and BMD of adolescents from a birth cohort conducted in São Luís – MA.Determinants throughout the life cycle of obesity, precursors of chronic diseases, human capital and mental health: a contribution of the Brazilian birth cohorts to the SUS, developed by the Federal University of Maranhão (UFMA), Ribeirão Preto Medical School (FMRP-USP) and the Federal University of Pelotas (UFPel). This cohort included live newborns of hospital birth of mothers living in the city of São Luís, between March 1997 and February 1998. Participants were evaluated in three phases of life: at birth, in childhood (7–9 years) and in adolescence (18–19 years). For this work, data from the first and third phases were used.This is a longitudinal study with data from a birth cohort conducted in São Luís – MA, Brazil, included in the consortium of RPS cohorts , entitledThe birth cohort was conducted in ten public and private hospitals that provided delivery care from 1997–1998. Systematic sampling was used with stratification proportional to the number of births in each hospital. Thus, one in each seven deliveries were recruited in each hospital unit. In this phase of the cohort, 2,541 live births, stillbirths, single births and multiple deliveries of women living in São Luís participated. We did not include births that occurred outside hospitals and those that occurred in hospitals where there were less than 100 deliveries per year..The target population included 96.3% of all deliveries in São Luís. Losses due to refusal or impossibility of locating the mother in hospitals occurred in 5.8% of the cases. Excluding multiple and stillborn deliveries, the final sample of this phase corresponded to 2,493 birthsIn the third phase, data collection was performed in 2016. To locate the participants, search procedures were used in school and university enrollments, in the addresses and telephone contacts recorded in the first and second phase of the cohort, in the records of military enlistment, and in social media. From these search strategies, 687 attended data collection.To increase the sample size of the study and prevent future losses, it was decided to include other adolescents born in the city of São Luís between 1997–1998 who had been excluded in the original sample of the cohort at the time of birth, and a draw was made in the SINASC database (information system on live births). A second strategy was the inclusion of adolescent volunteers identified in schools, universities and social media. Data on the birth of these adolescents were answered by the mother. The following criteria were taken into account for the registration: being born in maternity, in the city of São Luís, in 1997.From this listing, a random draw was made, obtaining a total of 4,593 born in 1997, in the city of São Luís. Of this total, it was possible to contact 1,716, to which all questionnaires were applied. In a second stage, volunteers were identified in schools, universities and social media, thus, contacting 110 adolescents. The volunteers were submitted to the same tests and questionnaires as the other participants of the original cohort..By these strategies to include new participants, 1,826 adolescents were added to the research from the third phase of this cohort, which was composed of 2,515 adolescents, from the original and those included from this phaseThus, adolescents born in São Luís – MA, between March 1997 and February 1998, who presented information about socioeconomic and demographic data, birth and their bone health were included. Pregnant adolescents were excluded, as they could not be submitted to bone densitometry examination, since the equipment emits a small amount of radiation during the evaluation, which totaled 2,112 adolescents for this study.®) program, which is online and secure for the registration and storage of research data.Data collection of the third phase occurred in 2016. Questionnaires and body composition assessment tests were completed by duly trained health professionals. The information was recorded in the Research Electronic Data Capture  when compared to men , and for those with 0–4 years of study (80.2%) compared to those with more than 12 years of study . However, the opening of the cohort for the insertion of adolescents brought greater participation of women with lower schoolingThe main explanatory independent variable was birth weight, used continuously. For individuals who participated in the cohort since birth, this variable was collected via medical records in maternity hospitals, and for those included in the third phase, it was self-reported by the mothers and confirmed by the SINASC database., was considered the dependent variable of the study. The evaluation of the bone mineral density of adolescents was performed by means of double X-ray densitometry (Dexa), based on enCORE and Lunar Prodigy model of the brand GE Healthcare®. The exam is safe and takes about 15 minutes to scan the entire body. The adolescent was asked to lie down at the table in supine position and remain motionless during the scan. The teenager wore light clothes, from lycra, tight to the body, typically a short shorts, for men and women, and a “top”, for women. They were barefoot, without dentures and other types of metallic materials.BMD, which is the relationship between the BMC and the area of the evaluated bone, expressed in g/cm. To determine low rates, BMD was categorized into normal when greater than or equal to −2 standard deviations, and low when less than −2 standard deviations. Bone mineral density was used as a continuous variable in the analyses.The Z-score calculated by the difference between the BMD and the mean population of the same age, gender, and ethnicity was considered. Total body measurement was considered as one of the most sensitive sites to evaluate bone mineral density because it is more associated with a higher risk of fractures and bone diseases in this populationThe maternal data used were all related to the period of birth: maternal age , knowing how to read and write (no/yes), marital status (with/without a partner), parity  and household income , tobacco use during pregnancy (no/yes), number of medical consultations during prenatal care (< 6 consultations and ≥ 6 consultations), and type of delivery .Data from adolescents: gender , age (18–19 years), maternal education , marital status (with/without a partner), economic class according to the Criteria of Economic Classification in Brazil , and gainful employment (yes/no). Dagitty.Directed acyclic graphs (DAGs) are causal diagrams used to select variables, with the objective of controlling confounding and avoiding unnecessary adjustments. A theoretical model was constructed, based on the literature, to analyze the association between birth weight and BMD in adolescence , using In the analysis of the DAGs, two models were suggested: one of total effect that excludes the mediating variables, suggesting adjustment for maternal age, marital status, parity, household income, prenatal care, tobacco use, type of delivery, the mother knowing how to read and write at the time of birth. The other model had direct effect, in which the mediating variables are added, seeking to decompose an unmediated effect. In this model, we analyzed the minimum set of variables: parity, household income, prenatal care, tobacco use, and the mother knowing how to read and write at the time of birth.® version 14.0. To verify whether the study variables followed the normal distribution pattern, distribution graphs (histograms) were constructed and the Shapiro Wilk test was applied. Categorical variables were described by absolute and relative frequencies. The continuous variables were described by mean and standard deviation.The data were exported from REDCap to be analyzed in the statistical program Stata.Multiple linear regression analysis was used to test the association between birth weight and BMD in adolescence. Residue analysis was also performed to check the assumptions of the linear regression model and identification of outliersSignificance level was set at 5%. The regression coefficient (Coef.) and the respective confidence intervals (95%CI) were estimated.The study was approved by the Research Ethics Committee of the Hospital das Clínicas of the Ribeirão Preto Medical School (No. 28/2004 and No. 10073/2009) and the Research Ethics Committee of the University Hospital/UFMA (No. 3104-476/2005). In 2015, it was also approved by the Research Ethics Committee of the University Hospital/UFMA (No. 19/2015). All participants signed the informed consent form.The adolescents of the cohort in São Luís had a prevalence of 2.8% for low bone mass for chronological age and the mean full-body Z-score was 0.19 (± 1.00). In the sample of 2,112 adolescents, 95.1% of mothers did not use tobacco during pregnancy, 68.4% were in the age group of 20–34 years, 95% could read and write, 77.5% lived with a partner, 49.6% were primiparous, and 87% had a household income of up to one minimum wage at the time of birth. Regarding prenatal care, 56% had six or more medical consultations, 63.9% had vaginal delivery, and 8.2% of the newborns had low birth weight .Female adolescents (52.3%), 18 years old (73.7%), single (96.8%), belonging to economic class C (76.2%), without gainful employment (60.8%), and attending high school (34.1%) prevailed .Birth weight was associated with BMD in adolescence . This effect of birth weight was attenuated in the analysis of the model adjusted for the confounders . However, in this direct effect model, the highest household income  and the mother knowing how to read and write  remained associated with the outcome .In the model for total effect  and direct  we observed a positive linear association between birth weight and bone mass in adolescence, even after adjusting for the variables family income  and mothers knowing how to read and write .. Therefore, the higher the value of birth weight, the higher the value of BMD achieved in adolescence  increases by 1 kg, bone mass in adolescence also increases by 0.10 g/cmescence .In this study, as birth weight increases, the BMD values in adolescence also increase, and we verified an independent association of the fit for household income and the mother knowing how to read and to write at the time of birth. By adjusting the direct effect model for the variables mentioned the magnitude of this association decreased..Few adolescents presented low bone mineral density (2.8%). Nevertheless, these values indicate previous bone mass impairment, because at 18 and 19 years old bone mass peaks, when it is expected to be at normal values. These findings are important for the investigation of factors, such as fetal development, birth weight, genetic factors — the main determinants of peak bone mass in adulthood — and modifiable factors , which are causing a lower BMD early. The fact that the health status of the skeleton, in the different stages of life, is a reflection of previous stages explains this association. Prospective studies show that low birth weight relates to the development of chronic diseases in adulthood, according to the theory Developmental Origins of Health and Disease (DOHaD).We observed a relevant finding: as birth weight increases by 1 kg, BMD in adolescence also increases by 0.10 g/cm, ratifying the theory that environmental stressors during intrauterine or early postnatal life cause changes in the sensitivity of growth plaque to GH and cortisol, reducing the size of the skeleton, which may lead to a decrease in mineralization, and predispose to an accelerated rate of bone loss during adulthood.Although how this process happens is still at issue, one of the possible explanations for this association would be the hormones GH (growth hormone) with cortisol as one of the determinants of bone loss. According to Baird et al., this programming can be classified into two studies: 1) those who explored the association between the physiological system of individuals who may have been “programmed” and the rate of bone mass loss due to aging; 2) studies that investigated the influence of the constitution of the body, nutrition, and lifestyle of mothers on the bone mass of their offspring.Birth weight is an important determinant of the peak bone mass reached in adolescence and one of the main factors for maintaining adequate levels of bone mass in adulthood. Despite the existence of some gaps in the mechanisms that involve this association, some studies corroborate the hypothesis that osteoporosis can be programmed at the beginning of development corroborated our findings by showing that birth weight is associated with BMD, contributing to the knowledge that this association is also observed in adolescents. This is an important finding for public health policies, since a reduction in bone mineral density strongly associates with an increased risk of fractures.A systematic reviewThe fact that the mother can read and write at the time of birth and has a household income of at least three minimum wages had a direct effect on the association studied here. Individuals exposed to favorable socioeconomic conditions and, consequently, healthier lifestyle seem to develop their potential for adequate BMD better.. The insufficient supply of nutrients to the fetus  may lead to adaptations of cells and their metabolism and, therefore, influence baseline levels of GH and cortisol in adolescence, because they are involved in obtaining peak bone mass and predispose to greater bone loss during adulthood.Mothers living in unfavorable socioeconomic conditions are more likely to conceive newborns with lower birth weight. From the epidemiological point of view, the earlier a preventive procedure begins, the better the chance of achieving desirable results.From the clinical point of view, considering that bone loss is a natural and irreversible process that occurs with aging, one of the best strategies for the prevention of osteoporosis is to optimize the peak bone mass of an individual.A study in Amsterdam showed a positive association between birth weight and whole body and hip BMD at 36 years old. The effects of birth weight on bone mineral density  are maintained until advanced ages, above 70 years, birth weight was the highest criterion of BMD. These results reinforce the hypothesis raised in this study that adequate birth weight may be important to maximize bone mass early, especially in adolescence.In a study conducted by Martínez-Mesa et al..Thus, low values of birth weight would act as risk markers for future reduced bone mineral density, since this situation is characterized by low bone mass and deterioration of bone tissue microarchitecture, with subsequent increase in fragility and susceptibility to fracturesThis study presented a limitation: the loss of participants during follow-up, especially in the third phase, due to difficulties in finding adolescents, despite the use of several search strategies. Such losses may have contributed to underestimate the associations that these strata prevailed more. The mothers of the adolescents included in the study reported their birth weights, however, we confirmed the numbers in SINASC, minimizing the possibility of memory bias.The adjustment of the proposed model excluded the food intake and the practice of physical activity of the adolescents, because DAG did not identified these variables.Highlights of the study: the longitudinal design of this study, the causal theoretical model based on DAG for the identification of the minimum set of variables necessary for adjustment to study the causal effect of birth weight on BMD. The evaluation of bone mineral density using DEXA, which is considered gold standard in adolescence, is also an important highlight of the study. Moreover, BMD is an important determinant of bone health at older ages, and this early evaluation, even in adolescence, was possible in this study.Although osteoporosis is a more prevalent disease in the older population, it should be prevented to promote bone health during childhood and adolescence, ensuring that BMD reaches its optimal peak and develops properly.The performance of studies that clarify and point to empirical understanding about the process of bone mass acquisition during intrauterine life, childhood, and adolescence until reaching the bone peak are of great relevance, clarifying the need for performances of studies in earlier stages. . A DMO tem sido amplamente estudada em adultos e idosos, fases em que ocorrem maiores prevalências de osteoporose e fraturas decorrentes da perda mineral óssea. Entretanto, a densidade mineral óssea alcançada na vida adulta depende do pico de massa óssea adquirido até os 20 anos de idade, o que torna importante a investigação em adolescentes. Acredita-se que uma perda precoce da DMO na adolescência pode estar associada a algumas patologias e/ou ao estilo de vida não saudável .O conteúdo mineral ósseo (CMO) é definido pela quantidade em quilogramas de osso que, dividido pelo seu tamanho, resulta na densidade mineral óssea (DMO) mensurada em g/cm.A mineralização óssea tem seu início na vida intrauterina e estende-se da infância até o início da idade adulta, mas é durante a infância e adolescência que ocorre o maior crescimento e desenvolvimento do tecido mineral ósseo.A massa mineral óssea e o risco de osteoporose podem ser influenciados por fatores do início da vida, como o peso ao nascer e restrição do crescimento intrauterino.A saúde óssea nas diferentes etapas da vida aparenta ser um reflexo de etapas anteriores, embora não exista um consenso de como este processo acontece. Acredita-se que a nutrição fetal insuficiente pode levar a mudanças permanentes no desenvolvimento do sistema neuroendócrino – fator de crescimento semelhante à insulina I e hormônio do crescimento – influenciando no desenvolvimento ósseo ao longo da vida.Em estudo de coorte norueguês, recém-nascidos com baixo peso ao nascer apresentaram picos mais baixos de massa óssea e maior frequência de osteoporose, implicando em risco maior de fratura na vida adulta.Uma revisão sistemática constatou que o peso mais elevado ao nascer é determinante para uma melhor saúde óssea, ratificando que poderia haver programação de massa óssea. O efeito pode ocorrer em crianças, mas é inconclusivo entre adolescentes. O efeito do peso ao nascer sobre a massa óssea entre as crianças foi na DMO e no CMOO efeito de variáveis precoces da vida e sua determinação sobre a densidade mineral óssea na adolescência têm sido pouco explorados em estudos longitudinais de base populacional. Contudo, o estudo da DMO em indivíduos mais jovens permite conhecer os determinantes precoces da saúde óssea, a fim de auxiliar no planejamento de intervenções individuais e coletivas para diminuir os efeitos da osteoporose no indivíduo adulto/idoso.Este estudo pretende analisar a associação entre o peso ao nascer e a DMO de adolescentes pertencentes a uma coorte de nascimentos realizada em São Luís – MA.Determinantes ao longo do ciclo vital da obesidade, precursores de doenças crônicas, capital humano e saúde mental: uma contribuição das coortes de nascimentos brasileiras para o SUS, desenvolvida pela Universidade Federal do Maranhão (UFMA), Faculdade de Medicina de Ribeirão Preto (FMRP-USP) e Universidade Federal de Pelotas (UFPel). Esta coorte incluiu recém-nascidos vivos de parto hospitalar de mães residentes no município de São Luís, entre março de 1997 e fevereiro de 1998. Os participantes foram avaliados em três fases da vida: ao nascimento, na infância (7–9 anos) e na adolescência (18–19 anos). Para este trabalho foram usados os dados da primeira e terceira fases.Trata-se de um estudo longitudinal com dados de uma coorte de nascimentos realizada em São Luís – MA, Brasil, incluída no consórcio de coortes RPS , intituladoA coorte dos nascimentos foi conduzida em 10 hospitais públicos e privados que forneciam assistência ao parto, no período de 1997–1998. Utilizou-se amostragem sistemática com estratificação proporcional ao número de nascimentos em cada hospital. Assim, foram recrutados um em cada sete partos em cada unidade hospitalar. Nesta fase da coorte participaram 2.541 nascidos vivos, natimortos, partos únicos e partos múltiplos de mulheres residentes em São Luís. Não foram incluídos os nascimentos que não ocorreram nos hospitais e os ocorridos em hospitais onde havia menos de 100 partos por ano..A população-alvo contemplou 96,3% de todos os partos ocorridos em São Luís. As perdas devido à recusa ou impossibilidade de localizar a mãe nos hospitais ocorreram em 5,8% dos casos. Excluindo-se partos múltiplos e natimortos, a amostra final desta fase correspondeu a 2.493 nascimentosNa terceira fase, a coleta de dados foi realizada no ano de 2016. Para a localização dos participantes, foram utilizados procedimentos de busca em matrículas escolares e de universidades, nos endereços e contatos telefônicos anotados na primeira e segunda fase da coorte, nos registros de alistamento militar e nas mídias sociais. A partir dessas estratégias de busca, 687 compareceram para a coleta de dados.Para ampliar o tamanho da amostra do estudo e prevenir perdas futuras, decidiu-se incluir outros adolescentes nascidos no município de São Luís entre 1997–1998 que não haviam sido incluídos na amostra original da coorte no momento do nascimento, realizando-se um sorteio no banco de dados do SINASC (sistema de informações sobre nascidos vivos). Uma segunda estratégia foi a inclusão de adolescentes voluntários identificados nas escolas, universidades e pelas mídias sociais. Os dados do nascimento destes adolescentes foram respondidos pela mãe. Os seguintes critérios foram levados em consideração para o cadastro: ter nascido em maternidade, na cidade de São Luís, no ano de 1997.A partir desta listagem foi feito sorteio aleatório, obtendo-se um total de 4.593 nascidos em 1997, na cidade de São Luís. Deste total, foi possível fazer contato com 1.716, aos quais foram aplicados todos os questionários. Em uma segunda etapa, os voluntários foram identificados nas escolas, universidades e pelas mídias sociais, sendo possível fazer contato com 110. Eles foram submetidos aos mesmos testes e questionários que os demais participantes da coorte original..Por meio dessas estratégias para inclusão de novos participantes, 1.826 adolescentes foram adicionados à pesquisa a partir da terceira fase desta coorte, a qual foi composta por 2.515 adolescentes, da original e aqueles incluídos a partir desta faseDessa forma, foram incluídos adolescentes nascidos em São Luís – MA, entre março de 1997 e fevereiro de 1998, que apresentaram informações acerca de dados socioeconômicos e demográficos, do nascimento e de sua saúde óssea. Não foram incluídas adolescentes grávidas, pois estas não puderam ser submetidas ao exame de densitometria óssea, uma vez que o equipamento emite uma pequena quantidade de radiação durante a avaliação, o que totalizou 2.112 adolescentes para este estudo.Research Eletronic Data Capture(Redcap®) que é online e seguro para o registro e armazenamento de dados de pesquisas.A coleta de dados da terceira fase ocorreu no ano de 2016. Foi realizado o preenchimento de questionários e exames de avaliação da composição corporal, por profissionais da área de saúde devidamente treinados. As informações foram registradas no programaPara verificar possível viés de seleção, as variáveis sexo e a mãe saber ler e escrever à época do nascimento foram comparadas entre os membros da coorte original e os adolescentes incluídos no estudo, onde pôde-se observar diferenças em direções opostas..As perdas do acompanhamento foram maiores para as mulheres  quando comparadas com os homens , e para aquelas de 0–4 anos de estudo  em comparação àquelas com mais de 12 anos de estudo . Contudo, a abertura da coorte para inserção dos adolescentes trouxe maior participação de indivíduos do sexo feminino e de mulheres com menor escolaridadeA variável independente explanatória principal foi o peso ao nascer, usada de forma contínua. Para os indivíduos que participaram da coorte desde o nascimento, essa variável foi coletada via prontuário nas maternidades, e, para aqueles incluídos na terceira fase, foi autorreferida pelas mães e confirmada pelo banco de dados do SINASC.. A avaliação da densidade mineral óssea dos adolescentes foi realizada por meio de densitometria por dupla emissão de raios-X (DEXA), baseado em enCORE e de modelo Lunar Prodigy da marca GE Healthcare®. O exame é seguro e leva cerca de 15 minutos para fazer o escaneamento do corpo inteiro. Foi solicitado ao adolescente deitar-se na mesa em decúbito dorsal e permanecer imóvel durante a realização do escaneamento. O adolescente usava roupa leve, de lycra, justa ao corpo, tipicamente uma bermuda curta, para homens e mulheres, e um “top”, para as mulheres. Ficavam descalços, sem próteses dentárias e outros tipos de materiais metálicos.A DMO foi considerada a variável dependente do estudo. É definida pela relação entre o CMO e a área do osso avaliada, sendo expressa em g/cm. Com o objetivo de determinar as taxas de baixa DMO, esta foi categorizada em normal quando maior ou igual a -2 desvios padrões, e baixa quando menor que -2 desvios padrões. A densidade mineral óssea foi utilizada como variável contínua nas análises.Foi considerado o Z-score calculado pela diferença entre a DMO do adolescente e a média da população de mesma idade, sexo e etnia. Foi considerada a medida de corpo total, vista como um dos sítios mais sensíveis para avaliar densidade mineral óssea por estar mais associado ao maior risco de fraturas e doenças ósseas nesta populaçãoOs dados maternos usados foram todos relativos à época do nascimento: idade materna , saber ler e escrever (não/sim), situação conjugal (com/sem companheiro), paridade  e renda familiar , tabagismo durante a gestação (não/sim), número de consultas realizadas durante o pré-natal (< 6 consultas e ≥ 6 consultas) e o tipo de parto .Dados dos adolescentes: sexo (masculino/feminino), idade (18–19 anos), escolaridade materna , situação conjugal (com/sem companheiro), classe econômica segundo o Critério de Classificação Econômica Brasil  e atividade remunerada (sim/não).browser Dagitty.Os gráficos acíclicos direcionados (DAG) são diagramas causais utilizados para selecionar variáveis, com o objetivo de controlar confundimento e evitar ajustes desnecessários. Um modelo teórico foi construído, com base na literatura, para analisar a associação entre o peso ao nascer e a DMO na adolescência , utilizNa análise dos DAG foram sugeridos dois modelos: um de efeito total – onde não são incluídas as variáveis mediadoras – que sugeriu ajuste para idade materna, situação conjugal, paridade, renda familiar, realização de pré-natal, tabagismo, tipo de parto, saber ler e escrever à época do nascimento. E outro, de efeito direto – o qual são acrescidas as variáveis mediadoras, buscando-se decompor um efeito não mediado. Neste modelo analisou-se o conjunto mínimo de variáveis: paridade, renda familiar, realização de pré-natal, tabagismo e a mãe saber ler e escrever à época do nascimento.®versão 14.0. Para verificar se as variáveis de estudo seguiam o padrão da distribuição normal, foram construídos gráficos (histogramas) de distribuição e aplicou-se o teste de Shapiro Wilk. As variáveis categóricas foram descritas por meio de frequências absolutas e relativas. As variáveis contínuas foram descritas pela média e desvio padrão.Os dados foram exportados do REDCap para serem analisados no programa estatístico Stataoutliers.Foi utilizada a análise de regressão linear múltipla para testar a associação entre o peso ao nascer e a DMO na adolescência. Realizou-se, também, análise de resíduos com o objetivo de checar os pressupostos do modelo de regressão linear e identificação deO nível de significância foi fixado em 5%. Estimou-se o coeficiente de regressão (Coef.) e os respectivos intervalos de confiança (IC95%).O projeto foi aprovado pelo Comitê de Ética em Pesquisa do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (Nº 28/2004 e Nº 10073/2009) e Comitê de Ética em Pesquisa do Hospital Universitário/UFMA (Nº 3104-476/2005). Em 2015, também aprovado pelo Comitê de Ética em Pesquisa do Hospital Universitário/UFMA (Nº 19/2015). Todos os participantes assinaram o Termo de Consentimento Livre e Esclarecido.Os adolescentes da coorte de São Luís tiveram prevalência de 2,8% para massa óssea baixa para a idade cronológica e o Z-escore médio de corpo inteiro foi de 0,19 . Na amostra de 2.112 adolescentes, 95,1% das mães não fumaram durante a gestação, 68,4% estavam na faixa etária de 20–34 anos, 95% sabiam ler e escrever, 77,5% viviam com companheiro, 49,6% eram primigestas e 87% tinham renda familiar de até um salário-mínimo na época do nascimento. Com relação ao pré-natal, 56% realizaram seis ou mais consultas de, 63,9% tiveram parto vaginal e 8,2% dos recém-nascidos apresentaram baixo peso ao nascimento .Observou-se também que prevaleceram adolescentes do sexo feminino , com 18 anos , solteiros , pertencentes à classe econômica C , sem atividade remunerada  e cursavam ensino médio  .O peso ao nascer mostrou-se associado à DMO na adolescência . Esse efeito do peso ao nascer foi atenuado na análise do modelo ajustado para os confundidores . Contudo, neste modelo de efeito direto, a renda familiar mais alta  e a mãe saber ler e escrever , permaneceram associados ao desfecho .No modelo para efeito total  e direto  foi observada associação linear positiva entre o peso ao nascer e a massa óssea na adolescência, mesmo após ajuste para as variáveis renda familiar  e mães que sabiam ler e escrever .2. Ou seja, quanto maior o valor do peso ao nascimento, maior será o valor de DMO alcançado na adolescência  aumenta em 1 kg, a massa óssea na adolescência também aumenta em 0,10 g/cmscência .Neste estudo, foi observado que à medida que o peso ao nascer aumenta, os valores da DMO na adolescência também aumentam, sendo verificada associação independente do ajuste para renda familiar e a mãe saber ler e escrever à época do nascimento. A magnitude desta associação foi reduzida pelo ajuste do modelo de efeito direto para as variáveis citadas..Poucos adolescentes apresentaram baixa densidade mineral óssea . Ainda assim, ressalta-se que estes valores são indicativos de comprometimento da massa óssea previamente, pois aos 18 e 19 anos ocorre o pico da massa óssea, momento em que se espera que ela esteja em valores normais. Estes achados são importantes para investigação de fatores, como o desenvolvimento fetal, peso ao nascer, fatores genéticos –principais determinantes da obtenção do pico de massa óssea na vida adulta –, além de fatores modificáveis , que estão causando uma menor DMO de forma precoce, o que configura um achado relevante. Esta relação pode ser explicada pelo fato do estado de saúde do esqueleto, nas diferentes etapas da vida, ser um reflexo de etapas anteriores. Estudos prospectivos demonstram que o baixo peso ao nascer tem relação com o desenvolvimento de doenças crônicas na idade adulta, segundo a teoria Origens do Desenvolvimento da Saúde e Doenças (DOHaD).Observou-se ainda que à medida que o peso ao nascer aumenta em 1 kg, a DMO na adolescência também aumenta em 0,10 g/cm, ratificando a teoria de que estressores ambientais durante a vida intrauterina ou pós-natal precoce provocam alteração na sensibilidade da placa de crescimento ao GH e ao cortisol, resultando em redução do tamanho do esqueleto, podendo levar a diminuição na mineralização, e predispor a uma taxa acelerada de perda óssea durante a vida adulta.Embora ainda não exista um consenso de como este processo acontece, uma das possíveis explicações para esta relação seria os hormônios GH (hormônio do crescimento) e cortisol estarem entre os determinantes da perda óssea. De acordo com Baird et al., essa programação pode ser classificada em dois estudos: 1) aqueles que exploraram a relação entre o sistema fisiológico de indivíduos que podem ter sido “programados” e a taxa de perda de massa óssea devido ao envelhecimento e 2) estudos que investigaram a influência da constituição do corpo, nutrição e estilo de vida das mães sobre a massa óssea de seus descendentes.É válido ressaltar que o peso ao nascer é um importante determinante do pico de massa óssea atingido na adolescência, bem como um dos fatores principais para manutenção de níveis adequados de massa óssea na vida adulta. Apesar da existência de algumas lacunas nos mecanismos que envolvem esta relação, alguns estudos corroboram a hipótese de que a osteoporose pode ser programada no início do desenvolvimentocorroborou com os nossos achados ao mostrar que o peso ao nascer está associado à DMO, contribuindo com o conhecimento que esta associação também é observada em adolescentes. Esta é uma descoberta importante para as políticas de saúde pública, uma vez que uma redução na densidade mineral óssea está fortemente associada a um risco aumentado de fraturas.Uma revisão sistemáticaPode-se observar ainda que, o fato de a mãe saber ler e escrever à época do nascimento e possuir uma renda familiar de, no mínimo, três salários mínimos teve efeito direto sobre a associação aqui estudada. Indivíduos expostos a condições socioeconômicas favoráveis e consequentemente estilo de vida mais saudável parecem desenvolver melhor o seu potencial de DMO adequada.. Acredita-se que o suprimento insuficiente de nutrientes ao feto  possa levar a adaptações das células e de seu metabolismoe, portanto, influenciar os níveis basais de GH e cortisol na adolescência, por estarem envolvidos na obtenção do pico de massa óssea e predispor à maior perda óssea durante a vida adulta.As mães que vivem em condições socioeconômicas desfavoráveis têm maiores chances de conceberem recém-nascidos com menor peso ao nascer. Já do ponto de vista epidemiológico, quanto mais cedo for iniciado um procedimento preventivo, melhor será sua chance de alcançar resultados desejáveis.Do ponto de vista clínico, considerando que a perda óssea é um processo natural e irreversível que ocorre com o envelhecimento, uma das melhores estratégias para a prevenção da osteoporose é otimizar o pico da massa óssea de um indivíduo.Estudo em Amsterdam mostrou associação positiva do peso ao nascer com a DMO do corpo todo e do quadril aos 36 anos. Os efeitos do peso ao nascer sobre a densidade mineral óssea  são mantidos até idades avançadas, acima de 70 anos, pôde-se observar que o peso ao nascer foi o maior critério de DMO. Resultados como esses reforçam a hipótese levantada neste estudo, de que o peso ao nascer adequado pode ser importante para maximizar a massa óssea de forma precoce, sobretudo na adolescência.Em um estudo realizado por Martínez-Mesa et al..Dessa forma, valores baixos de peso ao nascer atuariam como marcadores de risco para densidade mineral óssea reduzida futura, uma vez que esta situação se caracteriza por baixa massa óssea e deterioração da microarquitetura do tecido ósseo, com subsequente aumento da fragilidade e susceptibilidade às fraturasEste estudo apresentou como limitação a perda de sujeitos durante o seguimento, principalmente na terceira fase, devido dificuldades para encontrar os adolescentes, apesar da utilização de diversas estratégias de busca. Tais perdas podem ter contribuído para subestimar as associações em que estes estratos foram mais prevalentes. O peso ao nascer foi relatado pelas mães dos adolescentes incluídos no estudo, entretanto, todos os pesos de nascimento desses adolescentes foram confirmados no SINASC, sendo minimizada a possibilidade de viés de memória.O consumo alimentar e a prática de atividade física dos adolescentes não foram incluídos no ajuste do modelo proposto, pois estas variáveis não foram identificadas pelo DAG.Como pontos fortes, destacam-se: o desenho longitudinal deste estudo, o modelo teórico causal baseado em DAG para a identificação do conjunto mínimo de variáveis necessário para ajuste, a fim de estudar o efeito causal do peso ao nascer sobre a DMO. A avaliação da densidade mineral óssea usando DXA, que é considerado padrão ouro na adolescência, também é um importante ponto forte do estudo. Além disso, a DMO é um determinante importante da saúde óssea em idades mais avançadas e essa avaliação precoce, ainda na adolescência, foi possível neste estudo.Ainda que a osteoporose seja uma doença mais prevalente em idosos, ela deve ser prevenida, a fim de promover a saúde óssea durante a infância e adolescência com o objetivo de garantir que a DMO atinja seu pico ótimo e se desenvolva adequadamente.A realização de estudos que esclareçam e apontem dados ao entendimento empírico sobre o processo de aquisição da massa óssea durante a vida intrauterina, infância e adolescência até atingir o pico ósseo são de grande relevância, o que deixa claro a necessidade de que estudos em fases mais precoces sejam realizados.


Editorial on the Research TopicEndotyping and phenotyping prematurity and its complicationsThe mechanisms triggering preterm birth are multifold and largely unexplored. However, evidence is increasingly supporting the hypothesis that the pathophysiological conditions eliciting preterm birth play a major role in the clinical picture and the development of complications of prematurity . Most ofThe objective of this research topic was to deepen the knowledge about the association between endotypes of prematurity and phenotypes of complications of prematurity. This topic covered different neonatal organs and systems as they can all be altered by the endotypes of prematurity.Su et al. used a propensity score matching analysis to evaluate the effect of HDP on clinical outcomes of extremely preterm or extremely low birth weight (EP/ELBW) infants. In this case-control study the incidence of PVL in the offspring of mothers suffering from HDP was significantly increased. The authors demonstrated that, after matching the six major covariates including sex, gestational age, birth weight, antenatal steroids administration and methods of conception, HDP increased the risk of PVL in EP/ELBW infants however had no significant effect on the survival rate at discharge, or the incidence of other complications. The possible explanation for this result may be related to the hypoxic intrauterine environment typical of HDP. Hypoxia is one the major upstream mechanisms of PVL , is the most common form of non-hemorrhagic brain injury in preterm infants . PVL is s of PVL . In the s of PVL . Placents of PVL .Amelio et al. reviewed the current knowledge on endothelial dysfunction in relation to the etiology of preterm birth. The type and extent of endothelial dysfunction may vary according to the intrauterine environment. The paper summarizes the available evidence on the type of endothelial damage in the infectious/inflammatory and dysfunctional placentation endotypes of prematurity, focusing on their molecular peculiar features, biomarkers, and clinical impact. In the given context, advancing endothelial characterization could be a promising way to provide patient-tailored care to the most vulnerable newborns.Similarly to brain maturation, the nature, timing, and extent of prenatal environment may alter fetal and neonatal endothelial function , 8. ChanGonzalez-Luis et al. showed a significant association between exposure to HDP and increased rate of pharmacological closure of PDA. In contrast, neither chorioamnionitis nor being small for gestational age were significantly associated with the response to therapy. Subgroup analyses showed that the higher response to COX inhibitors in the HDP group was significant for indomethacin but not for ibuprofen or for the studies using both drugs. However, meta-regression showed that this difference between the drugs was not statistically significant. These data suggest that the pathologic condition that triggers prematurity may alter the response to pharmacological treatment of PDA and may help address uncertainties around PDA management.Individual studies have suggested that prenatal conditions such as chorioamnionitis or HDP may also affect the therapeutic response to pharmacological agents in preterm infants . In partBruno et al. described four different cardiopulmonary ultrasound patterns of evolving and established chronic lung disease of prematurity and the consequent therapeutic choices. In the reported cases, the histological examination of the placental material and the identification of the endotypes of prematurity were consistent with the CPUS patterns. This approach, if confirmed in prospective studies, may guide the personalized management of infants suffering from evolving and established BPD, optimizing the chances of success of the therapies and at the same time reducing the risk of exposure to inadequate and potentially harmful drugs.Bronchopulmonary dysplasia (BPD), is a preterm-related chronic lung disease  that mayRecently, the public health mitigation measures during COVID-19 lockdowns around the world offered an unprecedented and unique “nature's experiment” influencing a multitude of host and environmental factors on the feto-maternal unit, and multiple studies suggested changes to preterm birth rates of EP/ELBW population . CalvertA better insight of the relationship between endotypes and phenotypes of prematurity may help target treatments in the view of personalized medicine and in the context of developments in artificial intelligence, potentially improving the outcome of the fragile preterm population.


Baker's cyst, or popliteal cyst, is typically arising in the popliteal fossa located between the semi-membranous tendon and the medial head of the gastrocnemius. Asymptomatic Baker's cyst does not require treatment. Surgical treatment may be considered after the failure of conservative measures when the cyst causes persistent pain and rarely compresses the adjacent neurovascular structure.We report an unusual presentation of Baker's cyst in a 43-year-old patient who complained of knee pain and after several months of conservative treatment. Following a physical and radiological examination, a Baker cyst was confirmed that compresses the tibial nerve. A surgical decompression and excision of the cyst was performed using the posterior approach to allow complete removal of the cyst's stalk and wall. Histopathological report confirms dense collagen without true epithelial lining. The patient was asymptomatic at 6 months of follow-up.It is important to recognize that a large Baker's cyst can be symptomatic and present as a compression syndrome of the adjacent neurovascular structure. The current case report described an early surgical management to treat a tibial nerve compression syndrome caused by a Baker cyst. A surgical decompression through a posterior approach may facilitate complete removal of the cyst wall.Baker's cyst is a common knee pathology that could rarely compress the adjacent neurovascular structures. The surgical decompression through a posterior approach results in favorable outcomes in symptomatic patients with failed conservative measures. •Baker’s cyst could be presented as a compression syndrome •Failed conservative treatment with deterioration of lower limb function necessitate surgical decompression•Surgical decompression allow complete removal of the ventral wall and stalk of the cyst, hence can be considered safe, and reproducible procedure Carolus Hospital, Jakarta, Indonesia. She suffered from a trivial trauma about 6 months before admission. She lost her balance because her left foot was caught by an uneven pedestrian. She complained of mild pain at the back of the knee. She also experienced discomfort from the knee to the calf region while doing daily activities. There was occasional numbness of the sole, but no weakness of the ankle and toe was found. She did not complain of mechanical symptoms (such as locking and clicking) and swelling.Physical examination revealed a popliteal mass aggravated by knee extension. The cyst was firm in full extension and tender when the knee is flexed. There was no joint line tenderness. Palpation of the mass was with discomfort but no pain. The circumferential measurement of both calves is the same. The range of motion is unremarkable. The integrity of the menisci was tested with Appley's and McMurray's tests which demonstrate a negative finding. The Homan sign which is a finding for pseudo-thrombophlebitis sign was absent. There was a hypesthesia of the posterolateral side of the calf and plantar foot. Motor functions remain normal. The pulsation of dorsalis pedis and the posterior tibial arteries were normal. The plain standing radiograph of the knee showed a slight narrowing of the tibiofemoral joint and a shadow of a soft tissue mass on the posterior side of the knee .Fig. 1ThUltrasound imaging of the knee revealed a large popliteal cyst containing fluid from the medial head of the gastrocnemius without any haematoma. The cyst was 8.2 × 7.4 cm in size, extending posterolaterally compressing the neurovascular bundle . The labThe patient was diagnosed with a Baker's cyst with compression of the tibial nerve. The patient was conservatively managed for 8 weeks with rest, a short course of non-steroidal anti-inflammatory therapy, and physiotherapy. Despite conservative measures, the patient is still symptomatic.3 viscous yellowish liquid was decompressed from the cyst and the fluid was sent for analysis. The intact cyst wall was secured with clamps .The patient was allowed to fully weight bear 2 weeks after the operation. She was asymptomatic after 3 and 6 months of follow-up. No follow-up sonogram was performed after surgery.3The exact cause of a popliteal cyst remains an enigma. However, it is generally accepted that the popliteal cyst is highly associated with intra-articular pathology, such as internal derangement of the knee. When the etiology of the cyst is associated with intra-articular pathology, such as meniscal injury, a surgeon should address the background disease to prevent cyst recurrence, which is usually performed with arthroscopic surgery. The patient presented in the current report was a popliteal cyst aggravated by recent trauma. The cyst was located in the posteromedial popliteal fossa due to the lack of structural resistance in this anatomic area of the joint capsule In 2007, Ji JH et al. reported patients with calf atrophy and foot drop that were caused by Baker's cyst located between the medial head of the gastrocnemius muscle and the semi-membranosus tendon. The same case had been reported earlier in 1994 by DiRisio et al. that tibial nerve branch compression resulted in leg pain and gastrocnemius atrophy due to a cyst in the anterior of the medial head gastrocnemius dan posteromedial to the joint capsule. This is a common manifestation of neurovascular compression because the tibial nerve is the most superficial and medial structure in the popliteal fossa.In 1970, Rauschning and Lindgren described the posterior approach for popliteal cyst excision in 41 patients The open posterior approach, traditionally, has been associated with high rates of recurrence due to inadequate excision or management of the underlying intra-articular pathology and care must be taken to avoid neurovascular structure. Snir et al. 4Baker's cyst, or popliteal cyst, is typically arising in the popliteal fossa located between the semi-membranous tendon and the medial head of the gastrocnemius. We reported a 43-year-old female who underwent an open posterior excision for a Baker cyst that was caused by compression of the tibial nerve. Posterior excision is a safe and straightforward treatment option for patients. Intraoperative decompression can facilitate complete removal of the ventral cyst wall.Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.Ethical approval is exempt/waived at our institution.Faculty of Medicine, Universitas Trisakti, Jakarta, IndonesiaErica Kholinne.N/A.Erica Kholinne, Endrotomo Sumargono: Conceptualization, Methodology; Ira Juliet Anestessia, Erica Kholinne, Dyonesia Ari Harjanti: Data curation, Writing - Original draft preparation; Dyonesia Ari Harjanti, Ira Juliet Anestessia: Visualization, Investigation; Endrotomo Sumargono: Supervision; Erica Kholinne: Validation; Erica Kholinne: Writing - Reviewing and editing.None declared.


Arthroscopy in popliteal cyst surgery enables addressing all components of its pathomechanism: the cyst wall, valvular mechanism, and concomitant intra-articular pathologies. Techniques differ as to the management of the cyst wall and the valvular mechanism. This study aimed to assess the recurrence rate and functional outcomes of a cyst wall and valve excising arthroscopic technique with concurrent intra-articular pathology management. The secondary purpose was to assess cyst and valve morphology and concomitant intra-articular findings.Between 2006 and 2012, 118 patients with symptomatic popliteal cysts refractory to at least three months of guided physiotherapy were operated on by a single surgeon using a cyst wall and valve excising arthroscopic technique with intra-articular pathology management. Patients were evaluated preoperatively and at a mean follow-up of 39 months (range 12–71) by ultrasound, Rauschning and Lindgren, Lysholm, and VAS of perceived satisfaction scales.p = 0.03).Ninety-seven out of 118 cases were available for follow-up. Recurrence was observed on ultrasound in 12/97 cases (12.4%); however, it was symptomatic only in 2/97 cases (2.1%). Mean scores improved: Rauschning and Lindgren from 2.2 to 0.4, Lysholm from 54 to 86, and VAS of perceived satisfaction from 5.0 to 9.0. No persistent complications occurred. Arthroscopy revealed simple cyst morphology in 72/97 (74.2%) and presence of a valvular mechanism in all cases. The most prevalent intra-articular pathologies were medial meniscus (48.5%) and chondral lesions (33.0%). There were significantly more recurrences in grade III–IV chondral lesions (Arthroscopic popliteal cyst treatment had a low recurrence rate and good functional outcomes. Severe chondral lesions increase the risk of cyst recurrence. The presence of a popliteal cyst (Baker’s cyst) in most cases is associated with concomitant intra-articular pathologies, which result in a persistent and extensive intra-articular effusion , 2. ThisTraditionally, treatment of this condition consisted either of nonoperative treatment or open surgery through a posterior approach , 7. UsuaCurrently, the treatment of popliteal cysts not only addresses the wall of the cyst but also targets the valvular mechanism and concomitant intra-articular pathologies, thus encompassing all components of its pathomechanism , 4. ThosThis study aimed to assess the recurrence rate and functional outcomes of a cyst wall and valve excising arthroscopic technique with concurrent management of intra-articular pathologies. The secondary purpose was to assess cyst and valve morphology and concomitant intra-articular findings.Ethical approval was obtained from District medical chamber . The study was designed in compliance with the Helsinki Declaration.This was a retrospective cohort study of consecutive patients presenting to the single centre suffering from symptomatic popliteal cysts. Between 2006 and 2012, 118 consecutive patients  were included in the study and all data were collected prospectively in the database. The diagnosis of a popliteal cyst was based on the physical examination, ultrasonography, and magnetic resonance imaging (MRI) and confirmed during arthroscopy. Prior to surgery, all patients underwent at least three months of intensive guided physiotherapy with no improvement. The mean preoperative Rauschning and Lindgren scale of the popliteal cyst symptoms were 2.2 point out of possible 3 points  according to a predefined, published technique . Ultrasonography of the popliteal fossa was used to evaluate for a cyst recurrence, which was defined as a presence of any amount of fluid within the gastrocnemius–semimembranosus bursa. Functional outcomes assessed included the Rauschning and Lindgren scale of the popliteal cyst symptoms  were lost to follow-up. The remaining 97 patients were assessed at a mean follow-up of 39 months (range 12–71 months).p = 0.03, Table The cyst was absent in 85 (87.6%) of 97 cases as assessed by means of ultrasonography. Therefore, an ultrasonographic recurrence rate was 12/97 (12.4%)  and a return of full knee range of motion occurred within 2.5 days on average.Simple morphology of the cyst was present in 72/97 (74.2%) cases. Complex cysts, multichamber cysts, or cysts divided by a septum were present in 25/97 (25.8%) patients. Eight of 97 (8.2%) cases were recurrences after an open cyst excision. Arthroscopy revealed the communication between the cyst and joint cavity with valvular mechanism in all patients. The valvular mechanism was in most cases created by the posteromedial capsule transverse fold (97.9% of cases). The morphology of the valvular mechanism is presented in Table The postoperative complications included transient calf swelling in 8/97 (8.2%) of cases, popliteal haematoma in 5/97 (5.2%) of cases, transient sensory deficit near posteromedial portal in 2/97 (2.1%) cases, and superficial soft tissue infection in 1/97 (1.0%) case. All complications resolved within weeks after surgery.The most important finding of this study was that an arthroscopic popliteal cyst excision technique led to a low recurrence rate and good functional outcomes. However, severe chondral lesions were associated with increased cyst recurrence risk.Comparison of the recurrence rates from this study with the literature is difficult due to reporting discrepancies with regard to definition of the cyst recurrence and the modality used to assess it. Gu et al. reported a recurrence rate of 0% as assessed on MRI at 12–36 months of follow-up . Ahn et In the current study, the popliteal functional outcomes after cyst excision were analyzed by the means of Rauschning and Lindgren score, Lysholm score, and VAS perceived satisfaction score. These scores were chosen in order to assess specifically popliteal symptoms by the means of Rauschning and Lindgren score as well as general symptoms of the knee by the means of the Lysholm score and the subjective satisfaction of the patients by the means of VAS perceived satisfaction score. What is more, in the current study, the assessed group covered many different reasons of popliteal cyst formation from sports lesions to advanced osteoarthritis and synovial diseases. Therefore, the authors chose not to use a score focused on a specific pathology. Gu et al., Ahn et al., Chen et al., and Lie et al. used the Rauschning and Lindgren score for assessment of functional outcomes. Despite differences in reporting, good functional improvement was achieved in those five arthroscopic studies –17. Han  Regarding the distribution of concomitant lesions, the presented reported case series does not differ significantly from previous reports. Sansone et al. has found intra-articular lesions in 94% of popliteal cyst cases . SpecifiConcerns of the safety of the procedure described in the current manuscript may occur due to relative proximity of neurovascular bundle. However, in case of the typical popliteal cyst localization in the gastrocnemius–semimembranosus bursa, the neurovascular bundle is protected by the medial head of gastrocnemius Fig. . In accoThe first limitation of this study was the wide dispersion of the follow-up, ranging from 12 to 71 months. Also, a relatively high percentage of patients 17.8%) were lost to follow-up. What is more, the age group in this study is younger than in the literature –17. This.8% were Our findings demonstrate arthroscopic popliteal cyst treatment had a low recurrence rate and good functional outcomes, and further severe chondral lesions (Outerbridge grade III vs. IV) lead to a significant increased risk of cyst recurrence.