Birth Weight In Boys Research Articles

What’s with the boys? Lower birth weight in boys from HPA-1a alloimmunized pregnancies – New insights from a large prospective screening study in Poland

Fetomaternal incompatibility in human platelet antigens (HPAs) can cause maternal alloimmunization, which in turn may lead to thrombocytopenia with or without intracranial hemorrhage (ICH) in the fetus or newborn. Retrospective studies suggest that boys from alloimmunized mothers may have higher risk of ICH and lower birth weight than girls. The objective of this study was to assess how maternal HPA-1a alloimmunization, sex of the neonate and birth weight relates in a large prospective cohort. Through a national screening study in Poland (PREVFNAIT) involving HPA-1 typing of 24,259 pregnant women during 2013–2017, 606 HPA-1a negative pregnant women and their offspring were identified and included. Various multivariate models were used to assess if and how maternal HPA-1a alloimmunization status was associated with birth weight and risk of having a small for gestational age (SGA) neonate, and if and how sex of the neonate mattered. Most immunized pregnancies had male fetuses (69 %). Women carrying a male fetus had increased likelihood of having an SGA newborn if they were HPA-1a alloimmunized compared to non-immunized mothers. Increasing maternal anti-HPA-1a antibody levels were significantly associated with reduced birth weight and SGA risk among male-fetus pregnancies, but not if the fetus was female. In conclusion, anti-HPA-1a antibodies in a male fetus pregnancy is associated with increased risk of SGA and lower birth weight, especially if the antibody level is high. Sex of the fetus may therefore be considered as a new clinical predictor of more severe FNAIT neonatal outcome.

Maternal Thyroid Function and Birth Weight in Twins.

ContextThyroid hormones are associated with birth weight in singleton pregnancy. Twin pregnancies need more thyroid hormones to maintain the normal growth and development of the fetuses compared with single pregnancy.ObjectiveWe aimed to investigate the association of thyroid hormones and birth weight in twins.MethodsThis was a retrospective cohort study in a Chinese population. Pregnant women who received regular antenatal health care and delivered live-born twins from 2014 to 2019 were included (n = 1626). Linear mixed model with restricted cubic splines and logistic regression models were used to estimate the association of thyroid hormones with birth weight and birth weight discordance in twins.ResultsWe observed that both thyrotropin (TSH) and free thyroxine (FT4) were not associated with birth weight in twins overall, while when stratifying on fetal sex or chorionicity, there were nonlinear association between FT4 levels and birth weight in boys (Pnonlinear < .001) and in dichorionic (DC) twins (Pnonlinear = 0.03). Women with levels of FT4 lower than the 10th percentile had a higher risk of birth weight discordance in their offspring than women with normal FT4 levels (range, 2.5 to 97.5 percentiles) (odds ratio = 1.58; 95% CI, 1.05-2.33).ConclusionOur study suggests there was an association of FT4, but not TSH, with birth weight and birth weight discordance varied by sex and chorionicity. These findings could have implications for obstetricians to be aware of the importance of FT4 levels in preventing birth weight discordance in twin pregnancy.

P–784 Neonatal follow-up of babies born derived from mono-pronuclear zygotes

Abstract Study question Are the neonatal outcomes normal of babies derived from the transfer of blastocysts derived from mono-pronuclear(1PN) zygotes? Summary answer There was no effect on growth or increase in congenital anomalies up to 18-months in babies of 1PN-derived births. What is known already 1PN zygotes are observed in ART, albeit at a low rate. We have previously reported that 80.7% of 1PN zygotes derived from IVF or ICSI had a biparental chromosome using Live Cell imaging techniques, and some of these developed to the blastocyst stage (Tokoro et al. ASRM 2013). Furthermore, we have reported that these blastocysts can result in a viable pregnancy and healthy live birth (Tsuji et al. ASRM2020). However, there is some uncertainty about the developmental mechanism of 1PN zygotes, and there is no clear consensus on their clinical utility. Study design, size, duration This was a retrospective study which included 55 cases where there was a live birth after single embryo transfer of a blastocyst derived from 1PN zygote. The incidence of birth defects, birth weight was recorded as well as a physical development survey of 25 children who responded to the 18-months follow-up survey. The time period was 72 months (January 2013 to December 2018). Participants/materials, setting, methods Patients seeking fertility treatment at an established private IVF clinic. We compared the birth weight, birth after18-months height and weight of children born to 1PN zygotes with data from a control, 2PN group. Statistical significance was determined using the t-test (level of P &amp;lt; 0.05). Main results and the role of chance The incidence of birth defects in 1PN embryo-derived infants was 1.8% (1/55). The average birth weight of boys in the 1PN group was 3105.6+/–360.3g, which was not significantly different from 3041.0+/–443.3 g in the 2PN group. In girls, the average birth weight was 3085.7+/–454.9 g in the 1PN group, which was not significantly different from the 2PN group (2938.9+/–311.5 g). The average height at 18-months, was 81.6+/–2.5 cm vs 80.5+/–3.4 cm for boys; 79.0+/–1.8 cm vs 79.0+/–3.4 cm for girls in the 1PN and 2PN groups, respectively. The average body weights of the 1PN and 2PN groups were 11.1+/–1.1 kg vs 10.7+/–1.1 kg for boys; 9.7+/–0.9 kg vs 10.1+/–1.0 kg for girls, respectively. There was no significant difference in average height and weight up-to the 18-months follow-up survey. Limitations, reasons for caution The incidence of 1PN derived births is low and the study was limited to cases of single blastocyst embryo transfer. Wider implications of the findings: The incidence of congenital anomalies in Japan was around 1.7 to 2%, and the incidence was similar in the 1PN. There was no difference in the birth weight and 18-months follow-up survey of the 1PN compared with the 2PN. We have demonstrated that there is clinical utility of 1PN embryo. Trial registration number Not applicable

Association between the pregnancy exposome and fetal growth.

Several environmental contaminants were shown to possibly influence fetal growth, generally from single exposure family studies, which are prone to publication bias and confounding by co-exposures. The exposome paradigm offers perspectives to avoid selective reporting of findings and to control for confounding by co-exposures. We aimed to characterize associations of fetal growth with the pregnancy chemical and external exposomes. Within the Human Early-Life Exposome project, 131 prenatal exposures were assessed using biomarkers and environmental models in 1287 mother-child pairs from six European cohorts. We investigated their associations with fetal growth using a deletion-substitution-addition (DSA) algorithm considering all exposures simultaneously, and an exposome-wide association study (ExWAS) considering each exposure independently. We corrected for exposure measurement error and tested for exposure-exposure and sex-exposure interactions. The DSA model identified lead blood level, which was associated with a 97 g birth weight decrease for each doubling in lead concentration. No exposure passed the multiple testing-corrected significance threshold of ExWAS; without multiple testing correction, this model was in favour of negative associations of lead, fine particulate matter concentration and absorbance with birth weight, and of a positive sex-specific association of parabens with birth weight in boys. No two-way interaction between exposure variables was identified. This first large-scale exposome study of fetal growth simultaneously considered >100 environmental exposures. Compared with single exposure studies, our approach allowed making all tests (usually reported in successive publications) explicit. Lead exposure is still a health concern in Europe and parabens health effects warrant further investigation.

Association between antenatal maternal anxiety and fetal middle cerebral artery Doppler depends on fetal gender

Objective: Several studies have demonstrated that antenatal maternal anxiety (AMA) during pregnancy is associated with an increased risk of abnormal fetal Doppler parameters and adverse perinatal outcomes. Despite these studies, the evidence of the association between them remains inconclusive due in part to the methodological limitations of existing studies. Hence, in the present study, we established strict criteria and excluded patients who may have moderate or confounding variables to investigate the relationship between AMA and fetal Doppler findings and adverse perinatal outcomes.Methods: This was a cross-sectional study of 160 healthy nulliparous pregnant women (gestational age 31–33 weeks) with uncomplicated obstetric histories, who underwent Doppler flow studies on uterine, umbilical and fetal middle cerebral artery (MCA). Maternal anxiety was measured by STAI-State and STAI-Trait inventory.Results: Statistical analyses revealed that STAI-Trait anxiety was associated with lower MCA pulsatility index at 31–33 weeks gestational age and lower birth weight for the female fetus. There were no significant differences in the birth weight of boys of mothers with high anxiety and without high anxiety.Conclusions: The adaptation of the fetus to this hostile environment as AMA differs by gender. Adaptation for the female fetus means the “brain sparing effect” and reduced birth weight. The findings emphasize the potential importance of maternal psychological wellbeing during pregnancy for fetal development.

Multi-behavioral obesogenic phenotypes among school-aged boys and girls along the birth weight continuum.

Evidence shows that extremes of birth weight (BW) carry a common increased risk for the development of adiposity and related cardiovascular diseases, but little is known about the role of obesogenic behaviors in this process. Moreover, no one has empirically examined whether the relationship between BW, obesogenic behaviors and BMI along the full low-to-high birthweight continuum reflects the U-shape pattern expected from common risk at both BW extremes. Our objective was to characterize physical activity, screen time, and eating behavior and their relationship to BMI as a function of BW among school-aged boys and girls. In this cross-sectional study, 460 children aged 6 to 12 years (50% boys) from Montreal, Canada provided information on sleeping time, screen time, physical activity levels, eating behavior (emotional, external and restrained eating) and anthropometrics (height, weight, BW) through parent reported questionnaires. BMI was normalized using WHO Standards (zBMI), and BW expressed as ratio using Canadian population standards (BW for gestational age and sex). Analyses were conducted using generalized linear models with linear and quadratic terms for BW, stratified by sex and adjusted for age, ethnicity and household income. In boys, physical activity and screen time showed U-shaped associations with BW, while physical activity had an inverted U-shaped in girls. Emotional and restrained eating had positive linear relations with BW in boys and girls. Sleep time and external eating were not associated with BW. A U-shaped relationship between BW and zBMI was found in boys but no association was found in girls. Only sleep (in boys and girls), and emotional eating (girls only) were related to zBMI and mediation of the BW-zBMI relationship was only supported for emotional eating. In conclusion, BW relates to obesogenic behaviors and BMI in both non-linear and linear ways, and these associations differed by sex.

Secular trends of birthweight in boys from 1950 to 2010

Birthweight is an indicator of fetal development and intrauterine conditions and is associated with future health outcomes. Secular birthweight trends prior to the 1970s are mostly unknown. Our aim was to explore secular birthweight trends in Swedish boys from 1950 to 2010. We have collected detailed growth data including birthweight from archived School Health Care records for children born in Gothenburg from 1946 and onwards and established a unique population-based cohort, the Body Mass Index Epidemiology Study (BEST). The birthweight cohort spans six decades (1950-2010) and includes 46,548 boys. The mean birthweight of the complete study cohort was 3580±562g. Linear regression analysis of the entire period revealed a minimal negative secular trend for birthweight (BETA=-0.4g/year; p<0.01). However, three distinct trends appeared during sub-periods: a decrease 1950-80, an increase 1980-2000 and another decrease 2000-2010. We demonstrate that birthweight in boys has undergone periodic decreases and subsequent increases, but the overall trend from the 1950s to the present is stable.

Economic downturns and infant health

We study the gender-specific impact of macroeconomic conditions around birth on infant health. We use a sample of over 50,000 respondents born between 1950 and 1994 from Lifelines—a cohort and biobank from the northern Netherlands. Our results show that high provincial unemployment rates decrease fertility and lead to a lower birthweight in boys. The negative impact of high unemployment on birthweight is particularly strong for boys born to older mothers and for babies born to smoking mothers.

Low birth weight is associated with increased fat intake in school-aged boys.

Evidence suggests that both high and low birth weight children have increased the risk for obesity and the metabolic syndrome in adulthood. Previously we have found altered feeding behaviour and food preferences in pre-school children and adults born with low birth weight. In this study, we investigated if birth weight was associated with different intake of fat, carbohydrate and/or protein at 6-12 years of age. This is a cross-sectional study where 255 guardians answered online and telephone questions including anthropometrics and demographic data, parental family food rules (food control, encouragement and restriction) and a complete web-based FFQ for their children (130 boys and 125 girls). Baseline demographic and parental food rules characteristics did not differ accordingly to sex. Linear regression models were conducted separately for each sex, adjusted for income, age and maternal age. There were no differences in total energy intake, but energy density (ED, energy content/g) was negatively associated with birth weight in boys. Macronutrient analysis showed that ED intake was from a greater intake of fat. Birth weight was not a significant predictor of protein and carbohydrate intake in boys. In girls, we saw a positive correlation between fat intake and cholesterol intake v. birth weight, but no association with ED intake (results did not remain after adjustment). The study shows that low birth weight is associated with altered fat intake in childhood in a sex-specific manner. It is likely that biological factors such as fetal programming of homoeostatic and/or hedonic pathways influencing food preferences are involved in this process.

Association Between the Pregnancy Exposome and Fetal Growth

Background: Several environmental contaminants were reported to possibly influence fetal growth, generally from single exposure family studies, which are prone to publication bias. The exposome paradigm offers perspectives to avoid selective reporting of findings and to control for confounding by co-exposures. Objectives: We aimed to assess the association of the pregnancy chemical and external exposomes with fetal growth. Methods: Within HELIX project, 131 prenatal exposures were assessed using biomarkers and environmental models in 1,287 mother-child pairs from six European cohorts. We investigated their associations with fetal growth using a deletion-substitution-addition (DSA) algorithm considering all exposures simultaneously, and an exposome-wide association study (ExWAS) considering each exposure independently. We corrected for exposure misclassification, and tested for exposure-exposure and sex-exposure interactions. Findings: Lead blood level was the only exposure associated with fetal growth in the DSA model (97g weight decrease for each doubling in lead concentration). No exposure passed the multiple testing-corrected significance threshold of ExWAS; without multiple testing correction, this model was in favor of a negative association of fine particulate matter concentration with birth weight; and of a positive sex-specific association of parabens with birth weight in boys only. No two-way interaction between exposure variables was identified. Interpretation: This first large-scale exposome study of fetal growth simultaneously considered over 100 environmental exposures. Compared to single exposure studies, our approach allowed making all tests (usually reported in successive publications) explicit. Lead exposure is still a health concern in Europe and parabens health effects warrant further investigation. Funding Statement: FP7/2007-2013, HELIX project (no 308333). Declaration of Interests: The authors declare no conflict of interest. Ethics Approval Statement: The study was approved by the relevant ethical committees from each country and an informed consent form was assigned from all participants, or the parents of the children.

Rapid Protective Effects of Early BCG on Neonatal Mortality Among Low Birth Weight Boys: Observations From Randomized Trials.

Three randomized trials (RCTs) in low-weight (<2.5 kg) infants have shown that Bacille Calmette-Guérin (BCG) vaccine nonspecifically reduces all-cause mortality in the neonatal period. Using data from 3 RCTs of early BCG (n = 6583) we examined potential sex differences in the timing of the mortality reduction in the neonatal period, presenting metaestimates of the main outcome mortality rate ratios (MRR) for BCG-vaccinated and controls. Among controls, boys had a particularly high mortality during the first week after randomization: male-female MRR 2.71 (95% CI, 1.70-4.50). During the first week, BCG had a marked beneficial effect for boys, reducing mortality 3-fold (MRR [BCG/no BCG] = 0.36 [0.20-0.67]). In weeks 2-4 the effect waned for boys (MRR = 0.91 [0.51-1.69]). In girls, the pattern was opposite with a limited effect in the first week (MRR = 0.85 [0.46-1.54]), but a significant reduction in weeks 2-4 (MRR = 0.56 [0.31-1.00]). This was consistent in all 3 trials. Verbal autopsies linked early benefit to fewer sepsis-related deaths among BCG-vaccinated boys. The marked reduction in mortality in the days after BCG vaccination in boys emphasizes the importance of providing BCG soon after birth. ClinicalTrials.gov (NCT00146302) and ClinicalTrials.gov (NCT00625482).

Maternal urinary paraben levels and offspring size at birth from a Chinese birth cohort

BackgroundParabens are suspected to impair fetal growth because of their endocrine disrupting effects. Epidemiological studies regarding the effects of prenatal exposure to parabens on birth outcomes are limited. ObjectivesOur aim was to evaluate the association between prenatal paraben exposure and size of infants at birth. MethodsWithin the longitudinal Healthy Baby Cohort (HBC) in Hubei Province, China, we randomly selected 1006 mother-infant pairs recruited in Wuhan City in 2014. Concentrations of parabens were measured in maternal urine collected before delivery. General linear models were used to analyze the associations of maternal parabens exposure levels with birth weight and birth length. ResultsThe specific gravity adjusted geometric means for urinary concentrations of methyl paraben (MeP), ethyl paraben (EtP), and propyl paraben (PrP) were 5.41, 0.11, and 0.94 ng/mL, respectively. Maternal urinary concentrations of parabens tended to be positively associated with birth weight in boys, while opposite trends were found in girls, though these associations were not significant. Higher maternal urinary levels of MeP were positively associated with birth length in boys (β = 0.30, 95% CI: 0.01, 0.58 for the medium tertile, and β = 0.30, 95% CI: 0.01, 0.58 for the highest tertile compared to the lowest tertile); however, no significant associations with birth length were observed in girls. ConclusionsMaternal urinary levels of MeP were positively associated with length at birth in boys. Besides, we did not find strong associations of the current exposure levels of parabens in Chinese pregnant women with size of infants at birth.

Prenatal exposure to perfluoroalkyl substances and anogenital distance at 3 months of age in a Danish mother-child cohort

In the Odense child cohort, serum concentrations of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured in 638 pregnant women. Birth weight, head and abdominal circumferences and gestational age were determined. Anogenital distance (AGD), the distance from the anus to the genital organs, and penile width were measured 3 months after expected date of birth in 511 children. PFOS, PFHxS, PFNA and PFDA were associated with a decreased AGD in girls (p-trend<0.05) after adjusting for age and weight-for-age standard deviation score. PFOS in the highest quartile was associated with a 2.8mm (95% confidence intervals −4.5; −1.1) reduction in AGD in girls. No such tendencies were seen in boys. However, a tendency toward increased birth weight in girls and reduced birth weight in boys suggests that sex-dimorphic effects may occur from endocrine disrupting effects of these substances.

Incense Burning during Pregnancy and Birth Weight and Head Circumference among Term Births: The Taiwan Birth Cohort Study.

Background:Incense burning for rituals or religious purposes is an important tradition in many countries. However, incense smoke contains particulate matter and gas products such as carbon monoxide, sulfur, and nitrogen dioxide, which are potentially harmful to health.Objectives:We analyzed the relationship between prenatal incense burning and birth weight and head circumference at birth using the Taiwan Birth Cohort Study. We also analyzed whether the associations varied by sex and along the distribution of birth outcomes.Methods:We performed ordinary least squares (OLS) and quantile regressions analysis on a sample of 15,773 term births (> 37 gestational weeks; 8,216 boys and 7,557 girls) in Taiwan in 2005. The associations were estimated separately for boys and girls as well as for the population as a whole. We controlled extensively for factors that may be correlated with incense burning and birth weight and head circumference, such as parental religion, demographics, and health characteristics, as well as pregnancy-related variables.Results:Findings from fully adjusted OLS regressions indicated that exposure to incense was associated with lower birth weight in boys (–18 g; 95% CI: –36, –0.94) but not girls (1 g; 95% CI: –17, 19; interaction p-value = 0.31). Associations with head circumference were negative for boys (–0.95 mm; 95% CI: –1.8, –0.16) and girls (–0.71 mm; 95% CI: –1.5, 0.11; interaction p-values = 0.73). Quantile regression results suggested that the negative associations were larger among the lower quantiles of birth outcomes.Conclusions:OLS regressions showed that prenatal incense burning was associated with lower birth weight for boys and smaller head circumference for boys and girls. The associations were more pronounced among the lower quantiles of birth outcomes. Further research is necessary to confirm whether incense burning has differential effects by sex.Citation:Chen LY, Ho C. 2016. Incense burning during pregnancy and birth weight and head circumference among term births: The Taiwan Birth Cohort Study. Environ Health Perspect 124:1487–1492; http://dx.doi.org/10.1289/ehp.1509922

Prenatal exposure to endocrine disrupting chemicals and birth weight—A prospective cohort study

ABSTRACTPrenatal exposure to endocrine disrupting chemicals may affect fetal development through disruption of hormonal actions and epigenetic modifications, potentially predisposing individuals to later on-set health risks, such as obesity. The objective of this study was to determine associations between biological exposure markers of various endocrine disrupting chemicals and birth weight in a newly established, prospective mother-child cohort in the Netherlands. Birth weight (n = 91) was obtained from birth records, and exposure to dichlorodiphenyldichloroethylene (DDE), three di-2-ethylhexyl phthalate (DEHP) metabolites, polychlorinated biphenyl-153, perfluorooctanesulfonic acid (PFOS), and perfluorooctanoic acid (PFOA) was determined in cord plasma. For DDE, exposure was also measured in breast milk. Linear regression analysis was used to determine associations between compounds and birth weight, which were stratified for gender and adjusted for a priori defined covariates. Increased exposure to DDE was associated with lower birth weight in boys (>95.89 ng L−1, −325.9 g, 95% CI −634.26 to −17.56), whereas in girls a tendency towards a higher birth weight was observed. Lower birth weights for boys were also observed for high exposure to MECPP, and to a certain extent also for PFOA. MEHHP and PFOS exposure on the other hand were associated with higher birth weights in boys. In girls no effects were observed for these compounds. It can be concluded that prenatal exposure to DDE, perfluorinated alkyl acids, and phthalates was associated with changes in birth weight in this population. Associations were gender specific, and appeared to be non-linear. Since the population was relatively small, results should be interpreted with caution.

Maternal anti-HLA class I antibodies are associated with reduced birth weight in thrombocytopenic neonates

In this comparative cross-sectional study, possible associations between maternal anti-HLA class I antibodies and birth weight in neonatal thrombocytopenia are explored. Although commonly detected in pregnancies and generally regarded as harmless, it has been suggested that such antibodies might be associated with fetal and neonatal alloimmune thrombocytopenia (FNAIT). As a link between FNAIT due to human platelet antigen 1a-specific antibodies and reduced birth weight in boys has previously been demonstrated, we wanted to explore whether maternal anti-HLA class I antibodies might also affect birth weight. To examine this, suspected cases of FNAIT referred to the Norwegian National Unit for Platelet Immunology during the period 1998–2009 were identified. Pregnancies where the only finding was maternal anti-HLA class I antibodies were included. An unselected group of pregnant women participating in a prospective study investigating maternal–fetal hemodynamics at the University Hospital North Norway during the years 2006–2010 served as controls. Twenty-nine percent of controls had anti-HLA class I antibodies. The thrombocytopenic neonates had a significantly lower adjusted birth weight (linear regression, P=0.036) and significantly higher odds of being small for gestational age (OR=6.72, P<0.001) compared with controls. Increasing anti-HLA class I antibody levels in the mother were significantly associated with lower birth weight and placental weight among thrombocytopenic neonates, but not among controls. These results indicate that maternal anti-HLA class I antibodies in thrombocytopenic neonates are associated with reduced fetal growth. Further studies are needed to test if placental function is affected.

Association between PM10 air pollution and birth weight after full-term pregnancy in Krakow city 1995-2009--trimester specificity.

The results of epidemiological studies indicate that the higher maternal exposure to air pollution, especially with particulate matter during pregnancy, the lower the infant's birth weight. The aim of this study was to estimate entire pregnancy and trimester-specific exposure of pregnant women in the city of Krakow, southern Poland, to fine particulate matter [≤10 µg (PM10)], and to assess its effect on the birth weight of boys and girls separately. The study group consisted of 85,000 singleton, live, full-term births in Krakow city during a 15-year period (data from the birth registry). The mean concentrations of the pollutant for each month of gestation were estimated using continuous municipal monitoring data. Multiple linear regression analyses indicated that the mean PM10 concentration during entire pregnancy was inversely associated with birth weight in girls and the group of boys and girls combined, after adjusting for maternal age, gestational age and year of birth; in boys the relationship was not statistically significant. Maternal exposure to PM10 during the first trimester was negatively associated with birth weight separately in girls and boys, and the group of boys and girls combined. However, the PM10 exposure during the second and third trimester of pregnancy was not associated with birth weight. PM10 air pollution at levels currently encountered in Krakow city adversely affect infant birth weight; however, the effect seems to be very small. The influence of particulate air pollution on foetal growth in early gestation is one of several possible explanations for the results, but further research is needed to establish possible biological mechanisms explaining the observed relationship.

Risk factors and trends in the rate of stillbirth in Hungary between 1971 and 2010

Objective: Possible risk factors and trends in the rate of stillbirth in Hungary between 1971 and 2010.Methods: Annual data of fetal birth weight, fetal gender, maternal age and marital status of the mother categories were available for both live and stillborn cases and were analyzed using negative binomial regression. A p value less than 0.05 was considered significant.Results: Male gender significantly increased risk of stillbirth (relative risk (RR):1.08; p < 0.001). The risk of stillbirth was also significantly associated with the maternal age (RR: 2.01 in the group older than 35 years, relative to younger mothers; p < 0.001), and the marital status (RR: 1.24 among the babies of an extramarital partnership; p < 0.001), this holding true for both fetal genders. However, a low birth weight ( < 2500 g) increased the risk of stillbirth more than 18-fold (RR: 18.47; p < 0.001) and there was a markedly higher risk of low birth weight in boys than in girls. Further, a strong negative correlation (r = −0.88) was detected between the real income per person of the overall population and the rate of stillbirth.Conclusions: These findings support the known risk factors of stillbirth and gender-specific analyses given an estimation of the risk of stillbirth in both boys and girls.

Shorter anogenital distance correlates with undescended testis: a detailed genital anthropometric analysis in human newborns

Are the anogenital distance (AGD) and stretched penile length (SPL) shorter in human newborn males with cryptorchidism? AGD is significantly shorter in boys with undescended testis (UDT) and this correlation may indicate that both have a common antecedent early in gestation. Animal studies have reported a critical time period during early gestation termed the male programming window (MPW) where androgen deficiency results in reduced AGD and penile length, as well as cryptorchidism and hypospadias. Two pilot human studies have explored this association but these studies were small and heterogeneous with regard to age, race and had selection bias. A prospective descriptive study involving measurement of AGD and SPL at birth in a racially homogenous sample of 1154 consecutive newborns was performed over a period of 6 months. All measurements were taken by a single trained observer (V.J.). All consecutively born male infants at a community hospital were classified as having descended and or UDT. Testicular position in the undescended group was graded as high scrotal, inguinal or non-palpable. AGD (from the centre of anus to the junction of the smooth and rugated skin of scrotum) and SPL were measured. The AGD index (AGDi) was calculated by dividing AGD by cube root of birthweight. Of the 1154 infants examined, 624 were males and 71 had UDT. AGD was significantly shorter in infants with UDT when compared with infants with descended testis (mean ± SD; 2.21 ± 0.36 versus 2.56 ± 0.31 cm; P < 0.001). AGDi was also significantly shorter in infants with UDT (mean ± SD; 1.68 ± 0.27 versus 1.81 ± 0.20 cm/kg⁻³; P < 0.001). Significance was maintained even when preterm (P < 0.001) and low birthweight boys (LBW) (P < 0.001) were excluded. SPL was also significantly shorter in infants with UDT (Mean ± SD; 3.08 ± 0.52 versus 3.31 ± 0.38 cm; P < 0.001) but the significance was not maintained when preterm (P = 0.119) and LBW boys (P = 0.666) were excluded. Birthweight, gestational age and length adjusted regression models showed significantly shorter AGD in infants with UDT, but SPL was not different. Infants with higher position of testis appeared to have a shorter AGD and SPL but the correlation did not reach statistical significance. No difference in AGD or SPL was noted between boys with unilateral and bilateral UDT. The present study did not include data pertaining to maternal or newborn health status. Also parental drug exposure or occupational exposures to endocrine-disrupting chemicals was not studied. These may possibly affect genital anthropometric measurements. The study strengthens the hypothesis of existence of MPW in humans. Shorter AGD in cryptorchid infants may reflect the effect of androgen disruption or deficiency during MPW. AGD may be a more reliable non-invasive marker of androgen action during MPW than SPL to predict reproductive outcomes in humans.

Male specific association between xenoestrogen levels in placenta and birthweight

BackgroundFetal exposure to endocrine disrupting chemicals may increase the risk for adverse health effects at birth or later in life. ObjectivesThe objective of this study is to analyze the combined effect of xenoestrogens on reproductive and perinatal growth outcomes (child birthweight, early rapid growth and body mass index (BMI) at 14months) using the biomarker total effective xenoestrogen burden (TEXB). Methods490 placentas were randomly collected in the Spanish prospective birth cohort Environment and Childhood (INMA) project. TEXB was used to assess the estrogenicity of placental samples in two fractions: that largely attributable to environmental organohalogenated xenoestrogens (TEXB-alpha), and that mostly due to endogenous estrogens (TEXB-beta), both expressed in estrogen equivalent units (Eeq) per gram of tissue. Linear or logistic regression models were performed adjusting for cohort and confounders. Sex interactions were investigated. ResultsThe median TEXB-alpha level was 0.76pMEeq/g (interquartile range (iqr): 1.14). In multivariate models, higher TEXB-alpha levels (third tertile, >1.22pMEeq/g; iqr: 1.73) were associated with increased birthweight in boys but not in girls (β=148.2g, 95% CI: 14.01, 282.53, pint=0.057). Additionally, higher TEXB-alpha values in boys were related with a lower risk of early rapid growth (OR=0.37; 95% CI: 0.15, 0.88) and with a non significant association with larger BMI z-scores at 14months of age (β=0.29; 95% CI: −0.11, 0.69). ConclusionsThese findings suggest that prenatal exposure to xenoestrogens may increase birthweight in boys, which might have an impact on child obesity and other later health outcomes.