Anogenital distance and penile width measurements in The Infant Development and the Environment Study (TIDES): methods and predictors

Association between prenatal phthalate exposure and ano-genital indices among offsprings in an Israeli cohort

Background

In-utero phthalate exposure was shown to be associated with shortened anogenital distance (AGD) in male newborns, but findings among female are inconsistent. While phthalate exposure among pregnant women in Israel is widespread, no study has examined the association with offspring AGD. The objective of the current study was to investigate the association between maternal phthalates urinary concentration and offspring AGD at time of delivery among a birth cohort in Israel.

Methods

We measured spot urinary concentration of monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-2-ethyl-5-hydroxyhexylphthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP) among women presenting to the delivery room at Shamir Medical Center in Israel. Birthweight, length and AGD were measured in all newborns using a standardized protocol. Each AGD measurement was adjusted to weight (ano-genital index). Confounders included socio-demographic characteristics, comorbidities and obstetrical history. Univariate and multivariate analyses assessed the associations between phthalates, confounders and AGD.

Results

Overall, 193 mother and infant were analyzed. All newborns were born at term and had normal Apgar scores. Mean maternal age was 32 ± 4.7 years old. Mean birth weight and pregnancy week were 3183 ± 498 g and 39 ± 1.3, respectively. Median (IQR) urinary phthalate concentration adjusted to creatinine (ug/g) were 3.96 (2.2-6.6), 1.22 (0.7-2), 10.84 (7-20.4), 6.36 (3.3-11.2) and 0.64 (0.4-1.1) for MBP, MBzP, MECPP, MEHHP and MEOHP, respectively. Univariate comparison showed a significant association between higher than median MBzP concentration, higher Ano-Fourchetal index (AFI: 4.4 vs. 4.1, p = 0.037) and Ano-clitoral index (ACI: 11.5 vs. 10.4, p = 0.032) in infants. Total urinary phthalates concentration ≥26.25 μg/g was significantly associated with smaller penile width index (3.5 vs. 3.7, p = 0.022), higher ACI (11.6 vs. 10.3, p = 0.013) and a trend towards significance for higher AFI (4.3 vs. 4.1, p = 0.055). Following multivariate linear regression only PWI remained significantly associated with total phthalate urinary concentration.

Conclusions

Maternal urinary phthalates concentration at delivery were not associated with female AGD, but total urinary phthalate concentration were inversely associated with penile width.

Estimation of Reference Values for External Genitalia Parameters in North Indian Preterm and Term Female Newborns

OBJECTIVES

To establish gestation-wise normative data of external genitalia measurements in North Indian term and preterm female newborns.

METHODS

In this cross-sectional descriptive study, institutionally-born female neonates between 28-42 wk gestation were consecutively enrolled between 24-72 h of life. Newborns with major congenital malformations, chromosomal anomalies, multifetal gestation and birth injuries were excluded. Data on various genital measurements were collected [Clitoral length (CL), clitoral width (CW), ano-clitoral distance (AGDAC), ano-fourchette distance (AGDAF) and anogenital ratio (AGR)].

RESULTS

One hundred ninety-eight of 508 neonates (39%) were preterm and 310 (61%) were term. Mean (± SD) CL and CW were 4.6 ± 1.8 mm and 3.9 ± 1.6 mm, respectively. Mean (± SD) values for AGDAF, AGDAC and AGR were 9.3 ± 1.8 mm, 30.2 ± 3.9 mm, and 0.31 ± 0.05, respectively. According to these results, term female newborns with CL more than 7 mm and/or CW more than 6 mm (95th centile) warrant evaluation for clitoromegaly. An anogenital ratio greater than 0.45 should be considered as a sign of virilization in a female neonate. Gestation-wise percentile charts for CL, CW, AGDAF, AGDAC and AGR were generated.

CONCLUSIONS

The percentile values defined in the study can serve as local normative data for accurate interpretation of genital measurements in North Indian female newborns and enable health care professionals for early identification of genital virilization.

Estimation of Reference Values for External Genitalia Parameters in North Indian Preterm and Term Male Newborns

OBJECTIVES

To generate gestation-wise normative data of external genitalia measurements in North Indian term and preterm male newborns.

METHODS

This was a hospital-based cross-sectional observational study. Male neonates born between 28-42 wk of gestation (at 24-72 h of life) were consecutively recruited in the study. Newborns with major congenital malformations, chromosomal anomalies, multifetal gestation and birth injuries were excluded. Data on various genital measurements were collected [Stretched penile length (SPL), penile width (PW), upper anogenital distance (AGDu), lower anogenital distance (AGDl) and anogenital ratio (AGR)].

RESULTS

Out of 532 newborns, 208 (39.1%) were preterm. Mean (± SD) SPL and PW were 27.9 ± 3.6 mm and 10.6 ± 1.3 mm respectively. The mean values for AGDl, AGDu and AGR were 20.13 ± 4.04 mm, 39.2 ± 5.59 mm, and 0.51 ± 0.07, respectively. SPL less than 21 mm in a term male newborn and 17.5 mm in preterm should be considered micropenis (<2.5 SD) in our population. Gestation-wise percentile charts for SPL, PW, AGDl, AGDu and AGR were generated.

CONCLUSIONS

The reference values and percentile charts generated can serve as local normative data for accurate interpretation of genital measurements in North Indian newborns, assessment of ambiguous genitalia and avoiding diagnostic errors.

Prenatal Substance Exposure: Associations with Neurodevelopment in Middle Childhood

OBJECTIVE

 Single-substance exposure effects on neurodevelopmental outcomes, such as problem behavior and intelligence quotient (IQ), have been studied in children for decades. However, the long-term consequences of polysubstance exposure are poorly understood.

STUDY DESIGN

 Longitudinal neurodevelopmental data were gathered from cohorts across the United States through the Environmental Influences on Child Health Outcomes Program. Data on prenatal exposure to opioids, nicotine, marijuana, and alcohol were collected from children ages 6 to 11 years (N = 256). Problem behavior was assessed using the Child Behavior Checklist (school-age version), and verbal IQ (VIQ) and performance IQ (PIQ) were assessed using the Weschler Intelligence Scale for Children, Fifth Edition. We first identified latent profiles in the overall sample, then evaluated differences in profile membership for children with and without prenatal substance exposure.

RESULTS

 Latent profile analysis identified two mutually exclusive categories: average VIQ and PIQ, with typical problem behavior, and below-average VIQ with average PIQ and clinically significant problem behavior. Children with prenatal nicotine and polysubstance exposures were more likely to be classified in the below-average VIQ, elevated problem behavior profile compared with children without prenatal nicotine exposure.

CONCLUSION

 The presence of clinically significant behavior problems in children with average PIQ, but below-average VIQ, could represent a unique endophenotype related to prenatal nicotine exposure in the context of other prenatal substance exposures.

KEY POINTS

· The neurodevelopmental consequences of prenatal polysubstance exposure are poorly understood.. · Children with prenatal polysubstance exposure exhibited reduced IQ and elevated problem behavior.. · We found significant behavior problems in children with average PIQ and below-average VIQ.. · This may represent a unique endophenotype related to prenatal nicotine exposure..

Prenatal phthalate exposure and sex steroid hormones in newborns: Taiwan Maternal and Infant Cohort Study

BACKGROUND

Newborn anogenital distance (AGD) has been associated with prenatal exposure of phthalates. The association between prenatal phthalate exposure and sex steroid hormones in newborns is unclear.

OBJECT

This study aimed to examine whether cord-blood sex hormone levels were associated with prenatal phthalate exposure and newborn anogenital distance (AGD).

METHODS

In the Taiwan Maternal and Infant Cohort Study, we recruited 1,676 pregnant women in their third trimester in 2012-2015 in Taiwan. We determined 11 urinary phthalate metabolites in pregnant women, three maternal and five cord-blood steroid sex-hormone concentrations. Five hundred and sixty-five mother-infant pairs with sufficient data were included. Trained neonatologists measured 263 newborns' AGD. We examined the associations of prenatal phthalate metabolite levels with AGD and hormones using linear regression models and evaluated correlations between maternal and cord-blood sex hormone levels and AGD.

RESULTS

Compared with the male newborns exposed to maternal phthalate metabolites at the first tertile, AGD was -3.75, -3.43, and -3.53 mm shorter among those exposed at the median tertile of di-2-ethylhexyl phthalate (DEHP) metabolites, monobenzyl phthalate (MBzP), and monomethyl phthalate (MMP), respectively. Compared with those who had exposed at the first tertile, cord-blood follicle-stimulating hormone (FSH) decreased among male newborns exposed at higher levels of MMP, mono-n-butyl phthalate (MnBP), MBzP and DEHP, and among female newborns exposed at higher levels of MMP, MBzP and mono(2-ethyl-5-hydroxyhexyl) phthalate. However, we did not observe significant correlations of maternal or cord-blood sex steroid hormones with newborns' AGDs.

CONCLUSIONS

Alterations in cord-blood sex steroid hormone levels were associated with prenatal phthalate exposures, particularly in male newborns. Women aspiring to be pregnant should be alerted of the need of reducing phthalate exposure.

Racial disparities affect the association between gestational urinary phthalate mixtures and infant genital measures

Background

Phthalates are ubiquitous anti-androgenic endocrine disrupting chemicals found in personal care products, medications, and many plastics. Studies have shown a racial disparity in phthalates exposure among U.S. women, which may also impact fetal development.

Methods

We conducted a prospective cohort study of gestational exposure to a phthalates mixture in a racially-diverse population to determine their association with genital development. Mid-gestation (18-22 weeks) urine was collected from 152 women who self-identified as non-Hispanic Black and 158 women who self-identified as non-Hispanic White in Charleston, South Carolina between 2011 and 2014. We measured eight phthalate monoester metabolites in urine using liquid chromatography tandem-mass spectrometry. Mid-gestational penile dimensions were measured using ultrasound and anogenital distances were measured postnatally. We used Bayesian kernel machine regression to estimate the associations among the mixture of phthalate metabolites and mid-gestation penile dimensions and postnatal anogenital distance measures among singleton male (n = 179) and female (n = 131) infants, adjusted for urinary specific gravity, maternal age, body mass index, education level, cigarette smoking, and gestational age at enrollment or birth weight z-score.

Results

We found a stronger association between greater phthalates and decreased anopenile distance among infants born to women who self-identified as Black. Mono (2-ethylhexyl) phthalate (MEHP) was the driving mixture component among Black women, and monobutyl phthalate (MBP) and monoethyl phthalate (MEP) were drivers among White women. We also identified a non-linear association between phthalates and lesser ultrasound penile volume among women who self-identified as Black with monoisobutyl phthalate (MiBP) and MBP being most important. We also found an association between greater phthalates and shorter anoclitoral distance among infants born to women who self-identified as Black, with MEP and monobenzyl phthalate (MBzP) contributing most to this association.

Conclusion

Our results suggest a disparity in the association between gestational exposure to a mixture of phthalates and fetal genital development among women who self-identified as Black compared to White.

Associations of Exposure to Air Pollution during the Male Programming Window and Mini-Puberty with Anogenital Distance and Penile Width at Birth and at 1 Year of Age in the Multicenter U.S. TIDES Cohort

BACKGROUND

Ambient air pollution may be a developmental endocrine disruptor. In animal models, gestational and perinatal exposure to diesel exhaust and concentrated particulate matter alters anogenital distance (AGD), a marker of prenatal androgen activity, in both sexes. Little is known in humans.

OBJECTIVES

We examined exposure to fine particulate matter (PM 2.5 ) and nitrogen dioxide (NO 2 ) in relation to human AGD at birth and at 1 year of age, focusing on exposures during critical windows of reproductive development: the male programming window (MPW; gestational weeks 8-14) and mini-puberty (postnatal months 1-3).

METHODS

The Infant Development and Environment Study (TIDES) recruited first trimester pregnant women (n = 687 ) at four U.S. sites (Minneapolis, Minnesota; Rochester, New York; San Francisco, California; and Seattle, Washington) from 2010 to 2012. We measured anus to clitoris (AGD-AC) and anus to fourchette (AGD-AF) in female infants at birth; in males, we measured anus to penis (AGD-AP), anus to scrotum (AGD-AS), and penile width at birth and at 1 year of age. Using advanced spatiotemporal models, we estimated maternal exposure to PM 2.5 and NO 2 in the MPW and mini-puberty. Covariate-adjusted, sex-stratified linear regression models examined associations between PM 2.5 and NO 2 and AGD.

RESULTS

In males, a 1 - μ g / m 3 increase in PM 2.5 exposure during the MPW was associated with shorter AGD at birth, but a longer AGD at 1 year of age (e.g., birth AGD-AP: β = - 0.35 mm ; 95% CI: - 0.62 , - 0.07 ; AGD-AS: β = 0.37 mm ; 95% CI: 0.02, 0.73). Mini-pubertal PM 2.5 exposure was also associated with shorter male AGD-AP (β = - 0.50 mm ; 95% CI: - 0.89 , - 0.11 ) at 1 year of age. Although not associated with male AGD measures, 1 -ppb increases in NO 2 exposure during the MPW (β = - 0.07 mm ; 95% CI: - 0.02 , - 0.12 ) and mini-puberty (β = - 0.04 mm ; 95% CI: - 0.08 , 0.01) were both associated with smaller penile width at 1 year of age. Results were similar in multipollutant models, where we also observed that in females AGD-AC was inversely associated with PM 2.5 exposure, but positively associated with NO 2 exposure.

DISCUSSION

PM 2.5 and NO 2 exposures during critical pre- and postnatal windows may disrupt reproductive development. More work is needed to confirm these novel results and clarify mechanisms. https://doi.org/10.1289/EHP12627.

Environmental exposure to per- and perfluoroalkyl substances in early pregnancy and newborn anogenital distance: A prospective cohort study

Per- and polyfluoroalkyl substances (PFAS) are persistent, ubiquitous pollutants, and the current epidemiological evidence regarding the impact of in utero exposure to PFAS on anogenital distance (AGD) is limited and inconclusive. The primary aim of this study was to investigate the potential associations between maternal exposure to PFAS during pregnancy and AGD in newborns. A total of 2273 mother-child pairs were recruited for this study, and both PFAS levels and AGD were measured. Multiple linear regression models were utilized to explore the relationships between individual PFAS and AGD. Additionally, quantile-based g-computation (QGC) was employed to assess the joint effects of mixtures of PFAS on AGD. Our findings showed that maternal exposure to PFOS (β = 0.518, 95% CI: 0.093, 0.942), PFNA (β = 0.487, 95% CI: 0.037, 0.937), PFDA (β = 0.443, 95% CI: 0.048, 0.838), PFUA (β = 0.434, 95% CI: 0.031, 0.838), and PFBS (β = 0.444, 95% CI: 0.124, 0.763) during early pregnancy had a significant positive association with AGD in boys. Similarly, in girls, maternal exposure to PFOS (β = 0.423, 95% CI: 0.006, 0.841), PFNA (β = 0.641, 95% CI: 0.207, 1.074), PFDA (β = 0.670, 95% CI: 0.306, 1.033), PFUA (β = 0.895, 95% CI: 0.509, 1.281), and PFBS (β = 0.474, 95% CI: 0.178, 0.770) had a positive association with AGD, while PFOA (β = -1.254, 95% CI: -1.786, -0.723) had a negative association. QGC models further confirmed that PFAS mixtures were positively associated with AGD. Moreover, PFBS was the primary contributor to the joint effects of PFAS mixtures on AGD. In summary, our study has provided further corroboration for the possibility that PFAS exposure can have an impact on AGD in both boys and girls. The use of AGD as a promising biomarker for endocrine disruption highlights the significance of our findings, which may have valuable clinical implications for reproductive diseases.

Ultra-processed food (UPF) intake in pregnancy and maternal and neonatal outcomes

PURPOSE

Ultra-processed food (UPF), as defined by the NOVA classification, is related to lower diet quality, which may adversely affect maternal health and neonatal outcomes. This study aims to describe nutrient intake of pregnant women by the share of UPF in the diet and to identify associations between UPF intake and maternal and neonatal outcomes.

METHODS

In this cross-sectional study, pregnant women (n = 206) were recruited upon arrival to the obstetrics ward for delivery, and asked to complete a Food Frequency Questionnaire (FFQ), and questionnaires regarding environmental exposures, and socio-demographic characteristics. Neonatal measurements and clinical data were obtained following delivery. UPF energy intake was expressed as absolute and in terms of percent from total energy. Women with high intake of energy from UPF were compared to those with low intake.

RESULTS

Among 206 pregnant women, dietary intake of UPF ranged from 15.6% to 43.4% of total energy in the first and fourth quartiles of UPF consumption, respectively. Women in the fourth quartile of energy from UPF had lower intakes of vitamin C, beta-carotene, vitamin B6, and potassium, which is indicative of inferior diet quality. Percent energy from UPF was associated with maternal obesity (BMI ≥ 30) (OR = 1.06, 95% CI: 1.06, 1.10, p = 0.008) and shorter male infant ano-genital distance (AGD) (B = -1.9, 95% CI: -3.5, -0.24, p = 0.02).

CONCLUSIONS

UPF intake during pregnancy is associated with undesirable maternal and neonatal outcomes and more research is needed to confirm these findings.

Prenatal Androgen Exposure and Traits of Autism Spectrum Disorder in the Offspring: Odense Child Cohort

Fetal androgen exposure may be associated with autism spectrum disorder (ASD). We studied 1777 mother-child pairs in the prospective Odense Child Cohort. Prenatal androgen exposure was assessed by maternal 3rd trimester testosterone concentrations, maternal polycystic ovary syndrome (PCOS), and 3 months offspring anogenital distance. ASD traits were assessed at age 3 years with the ASD-symptom scale of the Child Behavior Checklist for ages 1½-5 years. Maternal testosterone was positively associated with traits of ASD in boys (p < 0.05). Maternal PCOS was associated with increased offspring ASD traits (p = 0.046), but became non-significant after excluding parental psychiatric diagnosis. Offspring anogenital distance was not linked to ASD traits. Higher prevalence of ASD in boys could be linked to higher susceptibility to fetal androgen exposure.

Associations between maternal urinary isoflavone concentrations and anogenital distance of offspring throughout infancy: a prospective cohort study

STUDY QUESTION

Are maternal urinary isoflavone (ISO) concentrations during pregnancy associated with anogenital distance (AGD) in infants at birth, and at 6 and 12 months of age?

SUMMARY ANSWER

Higher maternal urinary ISO concentrations during pregnancy were associated with longer AGD in infants of both sexes, and equol (EQU) and daidzein (DAD) were identified as the important ISO mixture components in the observed associations.

WHAT IS KNOWN ALREADY

Evidence of the association of prenatal exposure to ISO with offspring's AGD is mainly derived from animal studies, which used different study designs and had inconsistent results. Only one human study has been reported and it found null associations between maternal ISO exposure during pregnancy and AGD among boys at birth, with a small sample size and a wide range of exposure windows. No human study on girls was found.

STUDY DESIGN, SIZE, DURATION

Prospective cohort study (Shanghai-Minhang Birth Cohort Study), with pregnant women recruited at 12-16 weeks of gestation in Shanghai, China between April and December 2012. One thousand two hundred and twenty-five live singletons were left in the cohort at delivery of which 480 mother-infant pairs had data on both maternal urinary ISO concentrations and at least one AGD measurement and were included in the present study. Anopenile distance (AGDAP) and anoscrotal distance (AGDAS) of boys and anoclitoral distance (AGDAC) and anofourchette distance (AGDAF) of girls were measured at birth and at 6 and 12 months of age.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Multiple linear regression models were used to examine the associations between maternal ISO concentrations and AGD. Bayesian kernel machine regression (BKMR) was implemented to examine both the overall effects of ISO mixture and the single effect of each ISO and identify important components of ISO mixture.

MAIN RESULTS AND THE ROLE OF CHANCE

A general profile of higher concentrations of maternal ISO associated with longer AGD in infants of both sexes was observed, when maternal education, parity, BMI before pregnancy (BMI, categorical variable), passive smoking during early pregnancy, age at delivery, gestational weeks and infant body size were adjusted for. Among boys, EQU was associated with increased AGDAS at birth and at 6 and 12 months, and DAD was associated with increased AGDAP at birth. Among girls, the associations of EQU and DAD with increased AGDAC and AGDAF at birth were found. When gestational weight gain and feeding patterns of infants in the first 6 months were additionally adjusted for, and maternal BMI was adjusted for as a continuous variable, more pronounced associations were observed, especially for associations of genistein (GEN), DAD and glycitein (GLY) with increased AGDAP and AGDAS at 6 months in boys. However, these associations were not always observed in the highest tertile group, and no consistent dose-response relationships were found. Similar results were observed in BKMR models, showing positive correlations of concentration of ISO mixture with increased AGDAS at both 6 and 12 months among boys, and increased AGDAC and AGDAF at birth among girls. Statistically significant increments of 4.96 mm (95% credible interval (CrI): 1.40, 8.52) and 1.07 mm (95% CrI: 0.02, 2.13) in AGDAS at 6 months among boys and AGDAC at birth among girls, respectively, were observed at the 75th percentile of ISO mixture, compared with 25th percentile. EQU and DAD were identified as the important components among ISO-AGD associations.

LIMITATIONS, REASONS FOR CAUTION

First, due to the short half-lives of ISO, the accuracy of a single spot urine sample reflecting ISO exposure during pregnancy may be limited, and thus may cause non-differential misclassification. Second, despite the adjustments for several important covariates in the study, unmeasured and residual confounding factors may remain a concern. Third, false discovery due to multiple testing may remain. Finally, the reduced sample sizes attributed to the loss of follow-up and missing data of confounders may limit our ability to detect an association, if any existed.

WIDER IMPLICATIONS OF THE FINDINGS

Prenatal ISO exposure may affect the reproductive development of offspring. As ISO can be widely detected in pregnant women, especially in Eastern countries, more studies are warranted to provide evidence of the effects of prenatal ISO exposure on long-term reproductive outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the National Key Research and Development Program of China (2021YFC2701003), the National Natural Science Foundation of China (22076123), the Science and Technology Commission of Shanghai Municipality (21ZR1454700 and 20ZR1448000), the Shanghai Municipal Health Commission (20194Y0160) and Innovation-oriented Science and Technology Grant from NHC Key Laboratory of Reproduction Regulation (CX2022-04). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

The effect of polycystic ovary syndrome history on neonatal anogenital distance: A prospective study in Turkish population

Aim: Embryonic anogenital length depends on fetal sex and testosterone. Children of women with a history of polycystic ovary syndrome (PCOS) who became pregnant may have different anogenital lengths due to hyperandrogenemia. Therefore, the aim of this study was to compare the anogenital lengths of male and female newborns of women with and without a history of PCOS. Material and Method: The study was designed prospectively. Pregnant women with PCOS and control group who gave birth at term (≥37-42 weeks) between March 2019 and March 2020 in XXX, Department of Obstetrics and Gynecology (blind review) were included in this study. Results: A total of 119 patients, including 21 mothers with PCOS and female newborns, 35 mothers with female newborns in the control group, 21 mothers with PCOS and male newborns and 42 mothers with male newborns in the control group, were included in this prospective study. Anogenital distance-anus fourchette (AGD-AF) measurement was significantly higher in the female newborns from mother with PCOS than in the female newborns from control group (18.1±2.5 vs. 14.1±1.6, p=0.046). Also, AGD-AF was 20.3±3.5 in the PCOS with hirsutism group and 15.2±1.5 in the PCOS without hirsutism group, and the difference between them was statistically significant (p=0.041). Conclusion: The anogenital distance may change in female newborns in the presence of maternal PCOS. Considering that AGD reflects fetal testosterone exposure, the findings may reflect increased testosterone exposure in female fetuses of pregnant women with PCOS. The results pave the way for new studies.

Diagnosis of DSD in Children—Development of New Tools for a Structured Diagnostic and Information Management Program within the Empower-DSD Study

Background: Current recommendations define a structured diagnostic process, transparent information, and psychosocial support by a specialized, multi-professional team as central in the care for children and adolescents with genital variations and a suspected difference of sex development (DSD). The active involvement of the child and their parents in shared decision-making should result in an individualized care plan. So far, this process has not been standardized. Methods: Within the Empower-DSD study, a team of professionals and representatives of patient advocacy groups developed a new diagnostic and information management program based on current recommendations and existing patient information. Results: The information management defines and standardizes generic care elements for the first weeks after a suspected DSD diagnosis. Three different tools were developed: a guideline for the specialized multiprofessional team, a personal health record and information kit for the child with DSD and their family, and a booklet for medical staff not specialized in DSD. Conclusions: The new information management offers guidance for patients and professionals during the first weeks after a DSD diagnosis is suspected. The developed tools’ evaluation will provide further insight into the diagnostic and information-sharing process as well as into all of the involved stakeholders’ needs.

Association of pre-pregnancy body mass index and gestational weight gain with neonatal anogenital distance in a Chinese birth cohort

Background

This study aimed to investigate the associations of pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with anogenital distance (AGD) among newborns.

Methods

The study included 556 mother-newborn pairs from the Jiashan birth cohort. AGD was measured as AGD_AP (from the center of the anus to the anterior base of the penis, where the penile tissue meets the pubic bone) and AGD_AS (from the center of the anus to the posterior base of the scrotum, where the skin changes from rugate to smooth) in males and AGD_AC (from the center of the anus to the clitoris) and AGD_AF (from the center of the anus to the posterior convergence of the fourchette) in females. Multiple linear regression models were used to estimate the associations of pre-pregnancy BMI and GWG, with AGD.

Results

After adjusting for pre-pregnancy BMI and other potential confounders, male newborns whose mothers had excessive GWG had shorter AGD_AP than those whose mothers had normal GWG. Male newborns whose mothers had normal pre-pregnancy BMI and inadequate/excessive GWG had shorter AGD_AP than the reference group where mothers had normal pre-pregnancy BMI and GWG in stratified analyses.

Conclusion

Gestational weight gain during pregnancy was associated with AGD in newborns in this birth cohort.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-022-01458-y.

In China, the prevalence of underweight and overweight/obesity remained high among women. Appropriate pre-pregnancy body mass index (BMI) and gestation weight gain (GWG) were critical to reduce the risk of adverse birth outcomes. The anogenital distance (AGD) was measured as an indicator of neonatal reproductive function and was associated with adverse reproductive outcomes in adults. Thus, we investigated the associations of both sub-optimal pre-pregnancy BMI, as well as GWG, with AGD among newborns to draw a picture about their effect on offspring reproductive health.

A total of 556 mother-newborns were included in the study from the Jiashan birth cohort in China. We extracted information about maternal lifestyles, social demographic characteristics, diet, and medical history from questionnaires conducted during 8–16 gestational weeks and medical records. AGD among newborns was measured within 3 days of delivery.

We found that maternal excessive GWG was associated with shorter AGD in male newborns after adjusting for maternal pre-pregnancy BMI in multiple linear regression models. The study also suggested that maternal inadequate GWG was associated with a shorter AGD in male newborns, which needed to be corroborated in further studies with a larger sample size.

In conclusion, health professionals shall implement sufficient intervention to prevent suboptimal GWG during prenatal checkups.

Sex-specific ranges and ratios for anogenital distance among Thai full-term newborns

Introduction

Anogenital distance (AGD) is a marker of prenatal androgen exposure and a tool for assessment of differences of sex development. Data for AGD in newborns have been published, but these findings may not be applicable to Thai newborns.

Aim

To provide the sex-specific ranges for AGD in Thai full-term newborns.

Methods

A cross-sectional study was conducted in term newborns in Thailand, during 2016–2018. AGD was measured from anus to anterior base of penis (AGD_AP) and to perineoscrotal junction (AGD_AS) in males and from anus to clitoris (AGD_AC) and to posterior fourchette (AGD_AF) in females. AGD ratio is defined as AGD_AS divided by AGD_AP in males and AGD_AF divided by AGD_AC in females.

Results

A total of 364 newborns were studied (male 51.4%). The mean AGD_AS, AGD_AP and AGD ratio in males were 25.20 ± 4.80, 52.60 ± 6.90 and 0.48 ± 0.08 mm, respectively. The mean AGD_AF, AGD_AC, and AGD ratio in females were 16.50 ± 3.90, 42.60 ± 6.20 and 0.39 ± 0.08 mm, respectively. There were significant differences between AGD_AS and AGD_AF, AGD_AP and AGD_AC, and AGD ratio between males and females (p < 0.001). The AGD_AS, AGD_AP, AGD_AF, AGD_AC were correlated with birth weight and length, but AGD ratio showed no correlation.

Conclusion

The sex-specific ranges for AGD in Thai full-term newborns were determined. AGD ratio is a useful marker of prenatal androgen exposure since it differs between sexes, but constant between races and did not vary by body size.

Prenatal Phthalate Exposure and Child Weight and Adiposity from in Utero to 6 Years of Age

BACKGROUND

Prenatal phthalate exposure has been associated with lower birth weight but also higher weight in childhood. Few studies have examined weight or adiposity from birth to childhood and thus cannot assess growth trajectories associated with exposure.

OBJECTIVE

We assessed associations between maternal phthalate exposures in pregnancy and child weight and adiposity measured prenatally through childhood (3-6 years of age).

METHODS

Within The Infant Development and the Environment Study (TIDES), a prospective pregnancy cohort, we analyzed a panel of phthalate metabolites in urine collected at two visits from early and late gestation (N=780). We estimated average phthalate metabolite associations with child weight z-scores from ∼20wk gestation (estimated by ultrasound), birth, and 1, 3, 4, and 6 years of age using linear mixed-effects (LME) models. We also modeled associations with adiposity z-scores from birth (weight for length) and 1, 3, 4, and 6 years of age [body mass index (BMI)] using LME models.

RESULTS

For weight, we observed inverse associations between several phthalate metabolites and birth weight z-scores, but no associations were observed with postnatal weight z-scores in LME models. Regarding adiposity, we observed inverse associations between phthalate metabolites and weight-for-length z-scores at birth, but positive associations were observed with BMI z-scores at 3-4 years of age in LME models. For example, mono-ethyl phthalate was associated with a 0.17-unit decrease in birth weight-for-length z-score [95% confidence interval (CI): -0.29, -0.05] and a 0.18-unit increase in 4-years-of-age BMI z-score (95% CI: 0.04, 0.32).

DISCUSSION

We observed associations between prenatal exposure to phthalates and lower weight at birth but not at childhood follow-up visits. However, for adiposity, we observed an interesting pattern of association with low adiposity at delivery as well as high adiposity at 3-4 years of age. Although it is not clear from our results whether these associations occur within the same children, such a pattern of adiposity in early life has been linked to cardiometabolic disease in adulthood and deserves special attention as an outcome in the study of prenatal exposures in the developmental origins of health and disease. https://doi.org/10.1289/EHP10077.

Ano-Scrotal Distance (ASD) : Is it a marker for the severity of chordee?

OBJECTIVE

To evaluate the relation between ASD and the severity of chordee and hypospadias in a referral center.

METHODS

The distance between the anal verge and proximal scrotal edge (ASD) was measured in hypospadias patients between 6 and 18 months between 2016 and 2020 in the operating room under anaesthesia. Patients older than 36 months and younger than 6 months were excluded. The patients were classified according to meatus into: Grade I (glandular or chordee without hypospadias), II (distal), III (proximal) and IV (perineal). Chordee was assessed by erection test and classified into 2 groups; Group I: no chordee or mild chordee <30 and Group II: with severe chordee >30. Short ASD was defined as ≤ 2.0 cm.

RESULTS

817 boys were included. The patients were classified according to the hypospadias grades I (180 pt), II (415 pt), III (120 pt) and IV (102 pt). The median ASD for group I was 3.07 cm (range 1.0-5.5), for group II 3.10 cm (range 1.5-5.0), for group III 2.40 cm (range 1.5-54.5) and for group IV 2.10 cm (range 1.0-3.5). The average ASD of the patients in Grade III and IV (2.26 cm) was significantly shorter than the average ASD of the patients in Grade I and II (3.09 cm) (p < 0.05). 184 patients had an ASD ≤2.0 cm. 38% of patients with glanular hypospadias (grade I) with ASD ≤ 2.0 cm had severe chordee.

CONCLUSION

This study shows that short ASD is a helpful marker of the severity of chordee and hypospadias. Patients with glanular hypospadias and short ASD have 38% chance of having severe chordee.

Reproductive Hormone Concentrations and Associated Anatomical Responses: Does Soy Formula Affect Minipuberty in Boys?

CONTEXT

Soy formula feeding is common in infancy and is a source of high exposure to phytoestrogens, documented to influence vaginal cytology in female infants. Its influence on minipuberty in males has not been established.

OBJECTIVE

To assess the association between infant feeding practice and longitudinally measured reproductive hormones and hormone-responsive tissues in infant boys.

METHODS

The Infant Feeding and Early Development study was a prospective cohort of maternal-infant dyads requiring exclusive soy formula, cow milk formula, or breast milk feeding during study follow-up. In the 147 infant boy participants, serum testosterone, luteinizing hormone, stretched penile length, anogenital distance, and testis volume were longitudinally assessed from birth to 28 weeks. We examined feeding-group differences in age trajectories for these outcomes using mixed-effects regression splines.

RESULTS

Median serum testosterone was at pubertal levels at 2 weeks (176 ng/dL [quartiles: 124, 232]) and remained in this range until 12 weeks in all feeding groups. We did not observe differences in trajectories of hormone concentrations or anatomical measures between boys fed soy formula (n = 55) and boys fed cow milk formula (n = 54). Compared with breastfed boys (n = 38), soy formula-fed boys had a more rapid increase in penile length (P = .004) and slower initial lengthening of anogenital distance (P = .03), but no differences in hormone trajectories.

CONCLUSION

Reproductive hormone concentrations and anatomical responses followed similar trajectories in soy and cow milk formula-fed infant boys. Our findings suggest that these measures of early male reproductive development do not respond to phytoestrogen exposure during infancy.

Maternal urinary levels of glyphosate during pregnancy and anogenital distance in newborns in a US multicenter pregnancy cohort

Human exposure to glyphosate has become ubiquitous because of its increasing agricultural use. Recent studies suggest endocrine disrupting effects of glyphosate. Specifically, in our work in rodents, low-dose early-life exposure to Roundup® (glyphosate-based herbicide) lengthened anogenital distance (AGD) in male and female offspring. AGD is a marker of the prenatal hormone milieu in rodents and humans. The relationship between glyphosate exposure and AGD has not been studied in humans. We conducted a pilot study in 94 mother-infant pairs (45 female and 49 male) from The Infant Development and the Environment Study (TIDES). For each infant, two AGD measurements were collected after birth; the anopenile (AGD-AP) and anoscrotal (AGD-AS) distances for males, and anoclitoral (AGD-AC) and anofourchette distances (AGD-AF) for females. We measured levels of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) in 2nd trimester maternal urine samples using ultra-high-performance liquid chromatography-tandem mass spectrometry. We assessed the relationship between exposure and AGD using sex-stratified multivariable linear regression models. Glyphosate and AMPA were detected in 95% and 93% of the samples (median 0.22 ng/mL and 0.14 ng/mL, respectively). Their concentrations were moderately correlated (r = 0.55, p = 5.7 × 10-9). In female infants, high maternal urinary glyphosate (above the median) was associated with longer AGD-AC (β = 1.48, 95%CI (-0.01, 3.0), p = 0.05), but this was not significant after covariate adjustment. Increased AMPA was associated with longer AGD-AF (β = 1.96, 95%CI (0.44, 3.5), p = 0.01) after adjusting for infant size and age at AGD exam. No associations were detected in male offspring. These preliminary findings partially reproduce our previous results in rodents and suggest that glyphosate is a sex-specific endocrine disruptor with androgenic effects in humans. Given the increasing glyphosate exposures in the US population, larger studies should evaluate potential developmental effects on endocrine and reproductive systems.

Cohort profile: Understanding Pregnancy Signals and Infant Development (UPSIDE): a pregnancy cohort study on prenatal exposure mechanisms for child health

PURPOSE

Extensive research suggests that maternal prenatal distress is reliably related to perinatal and child health outcomes-which may persist into adulthood. However, basic questions remain regarding mechanisms involved. To better understand these mechanisms, we developed the Understanding Pregnancy Signals and Infant Development (UPSIDE) cohort study, which has several distinguishing features, including repeated assessments across trimesters, analysis of multiple biological pathways of interest, and incorporation of placental structure and function as mediators of child health outcomes.

PARTICIPANTS

Women with normal risk pregnancies were recruited at <14 weeks gestation. Study visits occurred in each trimester and included extensive psychological, sociodemographic, health behaviour and biospecimen collection. Placenta and cord blood were collected at birth. Child visits (ongoing) occur at birth and 1, 6, 12, 24, 36 and 48 months of age and use standard anthropometric, clinical, behavioural, biological and neuroimaging methods to assess child physical and neurodevelopment.

FINDINGS TO DATE

We recruited 326 pregnancies; 294 (90%) were retained through birth. Success rates for prenatal biospecimen collection were high across all trimesters (96%-99% for blood, 94%-97% for urine, 96%-99% for saliva, 96% of placentas, 88% for cord blood and 93% for buccal swab). Ninety-four per cent of eligible babies (n=277) participated in a birth examination; postnatal visits are ongoing.

FUTURE PLANS

The current phase of the study follows children through age 4 to examine child neurodevelopment and physical development. In addition, the cohort participates in the National Institutes of Health's Environmental influences on Child Health Outcomes programme, a national study of 50 000 families examining early environmental influences on perinatal outcomes, neurodevelopment, obesity and airway disease. Future research will leverage the rich repository of biological samples and clinical data to expand research on the mechanisms of child health outcomes in relation to environmental chemical exposures, genetics and the microbiome.

Association between prenatal exposure to polybrominated diphenyl ethers and anogenital distance in girls at ages 0-4 years

Anogenital distance (AGD) is a sensitive marker for the effect of in utero hormonal disturbance. However, studies on the associations between prenatal exposure to polybrominated diphenyl ethers (PBDEs), a group of endocrine disruptors, and AGD are limited. We examined the associations between prenatal PBDE exposure and AGD in girls at ages 0-4 years in the Shanghai-Minhang Birth Cohort Study. We measured PBDE in cord plasma collected from 148 girls at birth. Of them, two AGD metrics (AGD_AC: from the anterior surface of the clitoral hood to the center of the anus; AGD_AF: from the posterior end of the fourchette to the center of the anus) were measured in 142, 114, 104 and 120 of girls at birth, 6, 12, and 48 months of age, respectively. Linear regression models and linear mixed models were used to evaluate the associations between PBDE exposure and AGD at ages 0-4 years. We found positive associations of PBDE exposure with AGD_AF and AGD_AC in linear regression models, although some associations only reached significance at 6 and 48 months of age. For AGD_AF, the associations were statistically significant for BDE-47, -99, and -100 at 6 months of age (β = 2.34, 95% CI (0.21, 4.48) for BDE-47; β = 2.21, 95% CI (0.05, 4.36) for BDE-99; β = 2.12, 95% CI (0.01, 4.23) for BDE-100), and for BDE-99 and -100 at 48 months of age (β = 4.49, 95% CI (1.27, 7.71) for BDE-99; β = 5.04, 95% CI (1.87, 8.22) for BDE-100), while statistically significant associations with AGD_AC were only observed for BDE-99, -100, -153, and ∑₅PBDEs at 48 months of age (β = 7.62, 95% CI (2.59, 12.64) for BDE-99; β = 7.04, 95% CI (2.01, 12.07) for BDE-100; β = 5.41, 95% CI (0.45, 10.38) for BDE-153; β = 5.05 mm, 95% CI (0.09, 10.01 for ∑₅PBDEs). A consistent pattern of positive associations between prenatal exposure to PBDEs and AGD was also observed in linear mixed models. The finding provided further insights into the adverse effects of PBDEs on reproductive development at low dose exposure.

Digit ratio, a proposed marker of the prenatal hormone environment, is not associated with prenatal sex steroids, anogenital distance, or gender-typed play behavior in preschool age children

Prenatal hormones have been proposed as key factors impacting child development as well as long-term health and disease. Digit ratio (the ratio of the lengths of the second to fourth digits; 2D:4D) has been proposed as a sexually dimorphic, noninvasive marker of prenatal androgen exposure that can be reliably measured in children and adults. To date, few longitudinal pregnancy cohort studies have examined childhood digit ratio in relation to other relevant measures including prenatal hormones and androgen-sensitive outcomes. To augment the current literature on this topic, we measured right-hand digit ratio in 4-year-old children participating in The Infant Development and the Environment Study, a multicenter longitudinal cohort study that has been following mother-child dyads since the first trimester of pregnancy (n = 321). We assessed sex differences in digit ratio and fit multivariable linear regression models to examine digit ratio in relation to: (1) child sex; (2) maternal sex steroid hormone concentrations in early pregnancy; (3) newborn anogenital distance, another proposed measure of sensitivity to prenatal androgens; and (4) gender-typical play behavior as measured by the Preschool Activities Inventory (PSAI) at age 4. We observed no sex difference in digit ratio; the mean 2D:4D was 0.97 ± 0.05 mm in both sexes. Furthermore, digit ratio was not associated with maternal sex steroid concentrations in early pregnancy, anogenital distance in either sex, or PSAI scores in either sex in covariate-adjusted models. In conclusion, we observed no evidence that early childhood digit ratio was associated with child sex or hormone-sensitive measures in this cohort.

Anthropometric biomarkers for abnormal prenatal reproductive hormone exposure in women with Mayer-Rokitanksy-Küster-Hauser syndrome, polycystic ovary syndrome, and endometriosis

OBJECTIVE

To study whether markers of prenatal exposure to reproductive hormones are related to Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, polycystic ovary syndrome (PCOS), and endometriosis.

DESIGN

Case-control study. Comparison of sex hormone-related external genital and digital characteristics in cases and controls.

SETTING

University hospital.

PATIENT(S)

We enrolled 172 women in four groups-women with MKRH, women with PCOS, women with endometriosis, and controls (43 in each group).

INTERVENTION(S)

Measurement of two anthropometric biomarkers: anogenital distance and digit ratio.

MAIN OUTCOME MEASURE(S)

Anogenital distance was measured from the anus to the anterior clitoral surface (AGDac) and from the anus to the posterior fourchette (AGDaf). For the digit ratio we used a direct, as well as a computer-assisted graphic measurement to measure the length of the second and fourth digit.

RESULT(S)

After adjustment for body mass index and age, AGDac was the shortest in endometriosis and the longest in PCOS groups, with a mean difference of 10 mm (95% confidence interval 3.1-16.8). AGDaf but not AGDac measures were found to be significantly larger in the MRKH group, with a mean difference compared with controls of 2.6 mm (95% confidence interval 0.1-5.2). The digit ratio was not significantly different between the groups.

CONCLUSION(S)

In this study we did find limited evidence for androgen exposure during the development of MRKH. This is compatible with the hypothesis that the uterovaginal agenesis may have been the result of temporary prenatal exposure to altered gonadal hormone concentrations. For endometriosis and PCOS we confirm previously observed associations for anogenital distance reflecting possible estrogen-based and androgen-based intrauterine origins, respectively.

DUTCH TRIAL REGISTRATION NUMBER

NTR7492.

Prenatal and early childhood exposure to phthalates and childhood behavior at age 7 years

BACKGROUND

Emerging evidence suggests that phthalate exposure may be associated with behavior problems in children and that these associations may be sex specific.

METHODS

In a follow up study of 411 inner-city minority mothers and their children, mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), monoisobutyl phthalate (MiBP), monethyl phthalate (MEP) and four di-2-ethylhexyl phthalate metabolites (DEHP) were quantified in maternal urine samples collected during the third trimester and in child urine samples at ages 3 and 5 years. The Conners' Parent Rating Scale-Revised: Long Form (CPRS) and Child Behavior Checklist (CBCL) were administered to the mothers to assess children's behavior problems at 7 years of age. The analysis included children with available measures of CBCL, CPRS and phthalates measured in maternal urine. We performed both Quasi-Poisson regression and a mixture analysis using Weighted Quantile Sum(WQS) regression to assess the risk for CPRS scores and for internalizing and externalizing behaviors (from the CBCL) following intra-uterine exposure to the phthalate metabolites for boys and girls separately.

RESULTS

Among boys, increases in in anxious-shy behaviors were associated with prenatal exposure to MBzP (Mean Ratio [MR] = 1.20, 95%CI 1.05-1.36) and MiBP (Mean Ratio (MR) = 1.22, 95%CI 1.02-1.47). Among girls, increases in perfectionism were associated with MBzP (MR = 1.15, 95%CI 1.01-1.30). In both boys and girls, increases in psychosomatic problems were associated with MiBP (MR = 1.28, 95%CI 1.02-1.60), and MnBP (MR = 1.28, 95%CI 1.02-1.59), respectively. Among girls, decreased hyperactivity was associated with two DEHP metabolites, mono(2-ethyl-5-oxohexyl) phthalate (MR = 0.83, 95%CI 0.71-0.98) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MR = 0.85, 95%CI 0.72-0.99). Using weighted Quantile Sum logistic regression, no associations were found between the Weighted Quantile Sum (WQS) of phthalate metabolites and CPRS scores or externalizing and internalizing behaviors. Nonetheless, when the analysis was performed separately for DEHP and non-DEHP metabolites significant associations were found between the WQS of DEHP metabolites and social problems in boys (OR = 2.15, 95%CI 1.13-4.06, p-value = 0.02) anxious-shy problems in girls (OR = 2.19, 95%CI 1.15-4.16, p = 0.02), and emotional lability problems in all children (OR = 0.61, 95%CI 0.38-0.97, p = 0.04). MEHP and MEOHP were the most highly weighted DEHP metabolites in WQS mixture. The analysis performed with CBCL scale corroborated these associations.

CONCLUSION

Concentration of non-DEHP metabolites was associated with anxious-shy behaviors among boys. DEHP phthalate metabolites were associated with decreased hyperactivity and impulsivity among girls on CPRS scores. These findings lend further support to the adverse associations between prenatal phthalate exposure and childhood outcomes, and clearly suggest that such associations are sex and mixture specific.

Anogenital distance in children born of mothers with polycystic ovary syndrome: the Odense Child Cohort

STUDY QUESTION

Are higher testosterone levels during pregnancy in women with polycystic ovary syndrome (PCOS) associated with longer offspring anogenital distance (AGD)?

SUMMARY ANSWER

AGD was similar in 3-month-old children born of mothers with PCOS compared to controls.

WHAT IS KNOWN ALREADY

AGD is considered a marker of prenatal androgenization.

STUDY DESIGN, SIZE, DURATION

Maternal testosterone levels were measured by mass spectrometry at Gestational Week 28 in 1127 women. Maternal diagnosis of PCOS before pregnancy was defined according to Rotterdam criteria. Offspring measures included AGD from anus to posterior fourchette (AGDaf) and clitoris (AGDac) in girls and to scrotum (AGDas) and penis (AGDap) and penile width in boys and body composition (weight and BMI SD scores) at age 3 months.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was part of the prospective study, Odense Child Cohort (OCC), and included mothers with PCOS (n = 139) and controls (n = 1422). The control population included women with regular menstrual cycles (<35 days) before conception and no signs of androgen excess (hirsutism and/or acne).

MAIN RESULTS AND THE ROLE OF CHANCE

AGD measures were comparable in offspring of women with PCOS compared to controls (all P > 0.2) despite significantly higher maternal levels of total testosterone (mean: 2.4 versus 2.0 nmol/l) and free testosterone (mean: 0.005 versus 0.004 nmol/l) in women with PCOS versus controls (both P < 0.001). In women with PCOS, maternal testosterone was an independent positive predictor of offspring AGDas and AGDap in boys. Maternal testosterone levels did not predict AGD in girls born of mothers with PCOS or in boys or girls born of women in the control group.

LIMITATIONS, REASONS FOR CAUTION

The diagnosis of PCOS was based on retrospective information and questionnaires during pregnancy. Women participating in OCC were more ethnically homogenous, leaner, more educated and less likely to smoke compared to the background population. Our study findings, therefore, need to be reproduced in prospective study cohorts with PCOS, in more obese study populations and in women of other ethnicities.

WIDER IMPLICATIONS OF THE FINDINGS

Our finding of the same AGD in girls born of mothers with PCOS compared to controls expands previous results of studies reporting longer AGD in adult women with PCOS. Our results suggest that longer AGD in adult women with PCOS could be the result of increased testosterone levels in puberty, perhaps in combination with weight gain.

STUDY FUNDING/COMPETING INTEREST(S)

Financial grants for the study were provided by the Danish Foundation for Scientific Innovation and Technology (09-067180), Ronald McDonald Children Foundation, Odense University Hospital, the Region of Southern Denmark, the Municipality of Odense, the Mental Health Service of the Region of Southern Denmark, The Danish Council for Strategic Research, Program Commission on Health, Food and Welfare (2101-08-0058), Odense Patient data Explorative Network, Novo Nordisk Foundation (grant no. NNF15OC00017734), the Danish Council for Independent Research and the Foundation for research collaboration between Rigshospitalet and Odense University Hospital and the Health Foundation (Helsefonden). There is no conflict of interest of any author that could be perceived as prejudicing the impartiality of the research reported.

Anogenital Distance in Healthy Infants: Method-, Age- and Sex-related Reference Ranges

CONTEXT

The use of anogenital distance (AGD) in clinical and epidemiological settings is increasing; however, sex-specific reference data on AGD and data on longitudinal changes in AGD in children is scarce.

OBJECTIVE

To create age-, sex-, and method-related reference ranges of AGD in healthy boys and girls aged 0-24 months, to assess the age-related changes in AGD and to evaluate the 2 predominantly used methods of AGD measurement.

DESIGN

The International AGD consortium comprising 4 centers compiled data from 1 cross-sectional and 3 longitudinal cohort studies (clinicaltrials.gov [NCT02497209]).

SETTING

All data were collected from population-based studies, recruiting from 4 maternity or obstetric centers (United States, Cambridge [United Kingdom], Odense, and Copenhagen [Denmark]).

SUBJECTS

This study included a total of 3705 healthy, mainly Caucasian children aged 0-24 months on whom 7295 measurements were recorded.

MAIN OUTCOME MEASURES

AGDAS (ano-scrotal), AGDAF (ano-fourchette), AGDAP (ano-penile), AGDAC (ano-clitoral), AGD body size indices (weight, body mass index [BMI], body surface area, and length), and intra- and interobserver biases.

RESULTS

We created age-specific reference ranges by centers. We found that AGD increased from birth to 6 months of age and thereafter reached a plateau. Changes in AGD/BMI during the first year of life were minor (0-6% and 0-11% in boys and girls, respectively).

CONCLUSIONS

Reference ranges for AGD can be used in future epidemiological research and may be utilized clinically to evaluate prenatal androgen action in differences-in-sex-development patients. The increase in AGD during the first year of life was age-related, while AGD/BMI was fairly stable. The TIDES and Cambridge methods were equally reproducible.

Maternal plasma concentrations of perfluoroalkyl and polyfluoroalkyl substances during pregnancy and anogenital distance in male infants

STUDY QUESTION

Are maternal plasma concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFASs) during pregnancy associated with anogenital distance (AGD) in male infants at birth, 6, and 12 months of age?

SUMMARY ANSWER

Higher maternal plasma concentrations of some PFASs were associated with shorter AGD in male infants at birth and 6 months of age.

WHAT IS KNOWN ALREADY

Two animal studies have found that exposure to PFASs was associated with shorter AGD in male rat fetuses and wild male minks. There is only one human study on the topic that did not identify consistent patterns between maternal serum concentrations of PFASs during pregnancy and AGD in male infants.

STUDY DESIGN, SIZE, DURATION

In the prospective cohort study, a total of 1292 eligible pregnant women were recruited at 12-16 weeks of gestation between April and December 2012 at the Maternal and Child Health Hospital of Minhang district in Shanghai, China. At delivery, 667 male singletons were born. They were then followed up at birth (n = 439) and at 6 (n = 411) and 12 months (n = 376) of age when anopenile distance (AGDAP) and anoscrotal distance (AGDAS) were measured.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 500 male infants who had both maternal plasma concentrations of PFASs and at least one AGD measurement of at three time points were included in the present study. Multiple linear regression models were used to evaluate the potential linear associations between maternal concentrations of PFASs and AGD.

MAIN RESULTS AND THE ROLE OF CHANCE

Maternal plasma concentrations (ln-transformed) of perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA) were inversely associated with AGDAS or AGDAP at birth (AGDAS: per ln unit increase in PFAS concentrations: β (95% CI): -0.65 (-1.27 to -0.02) mm for PFOS; -0.58 (-1.11 to -0.06) mm for PFDA; and -0.57 (-1.09 to -0.06) mm for PFUdA; AGDAP: per ln unit increase in PFAS concentrations: β (95% CI): -0.63 (-1.24 to -0.01) mm for PFDA and - 0.76 (-1.36 to -0.16) mm for PFUdA). At 6 months of age, per unit increase in maternal ln concentrations of PFOS and perfluorotridecanoic acid (PFTrDA), AGDAS decreased on average by -2.21 (95% CI: -4.28 to -0.14) and -1.11 (95% CI: -2.17 to -0.06) mm, respectively. Additionally, ln-transformed perfluorooctanoic acid (PFOA) showed nonsignificant but inverse associations with both AGDAS and AGDAP at 6 months of age. We found no significant associations between ln-transformed maternal concentrations of PFASs and either AGDAS or AGDAP at 12 months of age. However, significantly inverse association of ln-transformed PFOA with AGDAP was observed in male infants who never or shortly breastfed (<3 months) at 12 months of age.

LIMITATIONS, REASONS FOR CAUTION

AGD measurements were performed by different examiners at each follow-up visit, and the intra-examiner variation was not assessed, which might cause intra-rater and inter-rater measurement errors. Additionally, our study may have selection bias since a considerable number of participants withdrew from the cohort although the differences in demographic characteristics were not statistically significant between included mother-infant pairs and those excluded. No statistical correction was made for multiple comparisons.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings may have important implications for the early development of genital health in male infants since PFASs can be detected in almost all pregnant women and infants worldwide.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the National Key Research and Development program of China (2018YFC1002801 and 2016YFC1000505), the Science and Technology Commission of Shanghai Municipality (16ZR1430100), the National Natural Science Foundation of China (81428011), and the Innovation-Oriented Science and Technology Grant from National Health Commission Key Laboratory of Reproduction Regulation (CX2017-06). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Associations between intrauterine exposure to polychlorinated biphenyls on neonatal ano-genital distance

Polychlorinated Biphenyls (PCBs) are widespread environmental contaminants. PCBs have endocrine disrupting properties which raises concerns regarding their effect on the developing fetus. This study aimed to examine the association between prenatal exposure to PCBs and anogenital distance (AGD) in newborns. Serum concentrations of PCB congeners -118, -138, -153 and -180 were measured in 175 pregnant women presenting to the delivery room. AGD was measured in their newborns. Regression models were used to estimate associations between maternal PCB exposure and infant anogenital measurements, controlling for possible confounding variables. Mean maternal serum concentrations were 2.95 ± 2.18 ng/g, 4.62 ± 3.54 ng/g, 7.67 ± 6.42 ng/g and 5.10 ± 3.91 ng/g for congeners -118, -138, -153 and -180, respectively. Higher maternal concentrations of PCBs were associated with reduced AGD measures in male infants. Higher maternal concentrations of PCB-138 and PCB-153 were associated with reduced ano-scrotal distances and higher maternal concentrations of all four PCB congeners were associated with reduced ano-penile distances. No significant associations were found between any PCB congener and any AGD measure in female newborns. This study demonstrates that intrauterine exposure to PCBs may be associated with reduced AGD in male newborns. More research is needed to reveal the implications for adult reproductive health.

Anogenital distance in newborn infants conceived by assisted reproduction and natural conception

RESEARCH QUESTION

Does anogenital distance (AGD) differ in newborn infants conceived through assisted reproduction technology (ART) compared with those conceived naturally?

DESIGN

This case-control study looked at anthropometric and anogenital measurements in 247 male and 200 female newborns born after ART (n = 121) or natural conception (n = 326), within 24 h of birth. Anogenital measurements included distance from the centre of the anus to the anterior clitoris (AGDAC) and to the posterior fourchette (AGDAF) in female infants, and from the centre of the anus to the posterior base of the scrotum (AGDAS) and to the anterior base of the penis (AGDAP) in male infants.

RESULTS

ART mothers were older, more likely to be nulliparous and delivered by Caesarean section at an earlier gestational week. AGDAS of male infants was approximately twice the AGDAF of female infants (17.6 ± 5.0 versus 9.1 ± 3.6 mm). AGDAF in female infants conceived by ART compared with those conceived naturally was not significantly different (8.8 ± 3.6 versus 9.3 ± 3.6 mm; P = 0.404). AGDAC were also comparable for both groups (27.4 ± 6.3 versus 27.7 ± 7.1 mm; P = 0.770). In male infants, no significant difference was seen between ART and natural conception groups in terms of AGDAS (17.4 ± 4.6 versus 17.7 ± 5.2 mm, P = 0.742) and AGDAP (37.5 ± 6.6 versus 38.0 ± 6.7 mm, P = 0.589). When adjusted for gestational age, weight, length and head circumference, mode of conception was not associated with differences in any of the anogenital measurements.

CONCLUSIONS

AGD measurements in infants conceived by ART are no different from those of infants conceived naturally.

Prenatal exposure to phthalates and male reproductive system development: Results from a Canadian pregnancy cohort study

Our objective was to determine if maternal first trimester urinary phthalate concentrations are associated with reduced penile length (PL) or width (PW) at birth in full term singletons. First trimester phthalate metabolite urinary concentrations were obtained from mothers participating in a Canadian pregnancy cohort study (MIREC). PL and PW were measured shortly after birth in the male offspring. Univariate and multivariable linear regressions were performed to study associations between maternal phthalate exposure and penile measurements, adjusting for confounders. On univariate analysis of 170 mother-infant pairs, PW showed an inverse relationship with the concentration of mono-3-carboxypropyl phthalate (MCPP-p = 0.016), which was not confirmed on multivariable analysis. On multivariable analysis controlling for infant's size and other confounders, no statistically signficant associations between phthalate metabolite concentrations and PL or PW were identified. In this population of Canadian women, there was no strong evidence to suggest an association between maternal first trimester urinary phthalates with PL or PW in term singletons.

The External Genitalia Score (EGS): A European Multicenter Validation Study

CONTEXT

Standardized description of external genitalia is needed in the assessment of children with atypical genitalia.

OBJECTIVES

To validate the External Genitalia Score (EGS), to present reference values for preterm and term babies up to 24 months and correlate obtained scores with anogenital distances (AGDs).

DESIGN, SETTING

A European multicenter (n = 8) validation study was conducted from July 2016 to July 2018.

PATIENTS AND METHODS

EGS is based on the external masculinization score but uses a gradual scale from female to male (range, 0-12) and terminology appropriate for both sexes. The reliability of EGS and AGDs was determined by the interclass correlation coefficient (ICC). Cross-sectional data were obtained in 686 term babies (0-24 months) and 181 preterm babies, and 111 babies with atypical genitalia.

RESULTS

The ICC of EGS in typical and atypical genitalia is excellent and good, respectively. Median EGS (10th to 90th centile) in males < 28 weeks gestation is 10 (8.6-11.5); in males 28-32 weeks 11.5 (9.2-12); in males 33-36 weeks 11.5 (10.5-12) and in full-term males 12 (10.5-12). In all female babies, EGS is 0 (0-0). The mean (SD) lower/upper AGD ratio (AGDl/u) is 0.45 (0.1), with significant difference between AGDl/u in males 0.49 (0.1) and females 0.39 (0.1) and intermediate values in differences of sex development (DSDs) 0.43 (0.1). The AGDl/u correlates with EGS in males with typical genitalia and in atypical genitalia.

CONCLUSIONS

EGS is a reliable and valid tool to describe external genitalia in premature and term babies up to 24 months. EGS correlates with AGDl/u in males. It facilitates standardized assessment, clinical decision-making and multicenter research.

Deciphering the Impact of Early-Life Exposures to Highly Variable Environmental Factors on Foetal and Child Health: Design of SEPAGES Couple-Child Cohort

In humans, studies based on Developmental Origins of Health and Disease (DOHaD) concept and targeting short half-lived chemicals, including many endocrine disruptors, generally assessed exposures from spot biospecimens. Effects of early-life exposure to atmospheric pollutants were reported, based on outdoor air pollution levels. For both exposure families, exposure misclassification is expected from these designs: for non-persistent chemicals, because a spot biospecimen is unlikely to capture exposure over windows longer than a few days; for air pollutants, because indoor levels are ignored. We developed a couple-child cohort relying on deep phenotyping and extended personal exposure assessment aiming to better characterize the effects of components of the exposome, including air pollutants and non-persistent endocrine disruptors, on child health and development. Pregnant women were included in SEPAGES couple-child cohort (Grenoble area) from 2014 to 2017. Maternal and children exposure to air pollutants was repeatedly assessed by personal monitors. DNA, RNA, serum, plasma, placenta, cord blood, meconium, child and mother stools, living cells, milk, hair and repeated urine samples were collected. A total of 484 pregnant women were recruited, with excellent compliance to the repeated urine sampling protocol (median, 43 urine samples per woman during pregnancy). The main health outcomes are child respiratory health using early objective measures, growth and neurodevelopment. Compared to former studies, the accuracy of assessment of non-persistent exposures is expected to be strongly improved in this new type of birth cohort tailored for the exposome concept, with deep phenotyping and extended exposure characterization. By targeting weaknesses in exposure assessment of the current approaches of cohorts on effects of early life environmental exposures with strong temporal variations, and relying on a rich biobank to provide insight on the underlying biological pathways whereby exposures affect health, this design is expected to provide deeper understanding of the interplay between the Exposome and child development and health.

Do stressful life events during pregnancy modify associations between phthalates and anogenital distance in newborns?

Anogenital distance (AGD) has been used as a marker of fetal androgen action to identify endocrine disrupting chemicals. A US study (TIDES) has reported that the association between some phthalates and reduced AGD in males was only apparent in sons of mothers reporting no stressful life events (SLEs) during pregnancy. The objective of the current study was to examine the potential modifying effect of SLEs and their subjective impact on associations between prenatal phthalates and AGD. First trimester urines from the MIREC Study were analysed for phthalate metabolites and AGD was measured in neonates. Post-delivery, the women answered questions on SLEs during the pregnancy. Women reporting 1 or more SLEs during pregnancy were considered a "higher stressor" group, whereas women reporting no SLEs or who reported a SLE that was perceived as not at all stressful were considered a "lower stressor" group. Multivariable linear regression models were fit stratified by stressor group. Maternal stressor, AGD and phthalates results were available for 153 females and 147 males. A summary measure of androgen-disrupting phthalates (Σ AD) was associated with significantly longer AGDs in females from the higher stressor group. These effect sizes were increased when the perceived impact was restricted to moderately or very much stressful. In males, all phthalates were associated with longer anopenile distance (APD), regardless of stressor group; however, higher Σ AD was associated with significantly longer APD in the lower stressor group. In contrast to the TIDES study, we did not observe shorter AGDs in male infants prenatally exposed to di-(2-ethylhexyl) phthalates, regardless of maternal stressor level. In conclusion, we were unable to replicate the findings of the TIDES study, but did find some evidence that prenatal SLEs may modify associations between phthalates and female AGD. Further research with other populations and measures of prenatal stress may shed more light on whether prenatal stress is an important effect modifier of associations between phthalates (or other chemicals) and anogenital distance.

Ovarian response is associated with anogenital distance in patients undergoing controlled ovarian stimulation for IVF

STUDY QUESTION

Is the length of the anogenital distance (AGD) a biomarker of ovarian reserve and response to controlled ovarian stimulation (COS)?

SUMMARY ANSWER

Shorter AGD is associated with presence of poor ovarian response.

WHAT IS KNOWN ALREADY

Organ development during prenatal life is influenced by the prevailing intrauterine environment, and it has been suggested that nutritional, environmental and toxic factors could affect ovarian reserve set prenatally. AGD is a biomarker of prenatal-hormonal environment and observational studies have shown an association between its length and reproductive parameters in both sexes.

STUDY DESIGN, SIZE, DURATION

This was a prospective cohort study of 437 women treated with IVF/ICSI conducted in a tertiary-care university hospital between January and December 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All women underwent their first COS for IVF/ICSI and reached criteria for oocyte retrieval. Based on the number of oocytes obtained, patients were divided into three groups: poor responders (≤3 oocytes) (n = 50), normoresponders (4-15 oocytes) (n = 332) and high responders (>15 oocytes) (n = 55). Before retrieval, the following patient data were recorded: age, body mass index (BMI), ovarian reserve markers (anti-Müllerian hormone [AMH], antral follicle count [AFC] and follicular stimulation hormone [FSH]), cause of infertility, total doses of gonadotropins used and ovarian sensitivity index (OSI). Patients with previous pregnancies, polycystic ovary syndrome (PCOS), endometriosis and previous ovarian or genital surgery were excluded. Anthropometric biomarkers of AGDAC (anus-clitoris) and AGDAF (anus-fourchette) were measured in all patients under sedation on the day of retrieval and before proceeding to oocyte pick-up. Multiple linear regression analyses were used to examine the association between both AGD and ovarian reserve markers, the total units of gonadotropins used, the number of oocytes obtained and the OSI. Logistic regression was used to predict poor response in COS for IVF/ICSI, while accounting for confounders such as age and BMI.

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline FSH, AMH, AFC and age were significantly different among the three groups of ovarian response, as were the units of gonadotropin used, and the ovarian sensitivity index (OSI) (P < 0.001). Both AGDAC and AGDAF measurements were positively correlated with AMH levels (r = 0.38 and r = 0.21; P < 0.05), AFC (r = 0.41 and r = 0.20; P < 0.05), the OSI (r = 0.24 and r = 0.19; P < 0.05) and the number of oocytes retrieved (r = 0.29 and r = 0.28, respectively; P < 0.05). Conversely, there was a negative correlation between both AGD measurements and the doses of gonadotropins used (r= -0.19 and r= -0.15; P < 0.05). The area under the curve (AUC) for prediction of poor response of AGDAC was 0.70 (95% CI 0.66, 0.75), which was comparable to the classic ovarian reserve markers, such as AFC and AMH. AGDAF showed a significantly worse predictive capacity for poor ovarian response (AUC 0.60 [95% CI 0.55, 0.60]) than AMH and AFC.

LIMITATIONS, REASONS FOR CAUTION

The population used for the study was a highly selected group of infertile women who underwent COS for IVF, so the findings of this research may not be applicable for general population. Besides, measurement or selection biases might have been possible and must be considered.

WIDER IMPLICATIONS OF THE FINDINGS

The findings of this study suggest that in utero exposure to certain hormonal environments could affect the ovarian reserve set prenatally.

STUDY FUNDING/COMPETING INTEREST(S)

None. The authors have no competing interests to declare.

In utero effects of maternal phthalate exposure on male genital development

BACKGROUND

Phthalates are used extensively in commercial and personal care products and maternal exposure is ubiquitous. Phthalates are anti-androgenic, but the potential effects of phthalates on male penile development have not been assessed in utero.

OBJECTIVE

The study aims to investigate the association between early pregnancy phthalate exposure and fetal penile development, overall and by race.

METHODS

Prospective cohort study of women with singleton pregnancies presenting for prenatal ultrasound between 18 and 22 weeks' gestation. Maternal urine samples were assayed for eight phthalate monoester metabolites. We used maternal phthalate levels at 18 to 22 weeks' gestation as predictors of fetal size using multiple linear regression models, adjusted for fetal gestational age, maternal age, race, smoking, and education. We incorporated a phthalate by race interaction into a second set of regression models.

RESULTS

We detected statistically significant race interactions for continuous phthalates with penile width. Race interactions were also suggested for penile length and volume using tertiles of phthalates with point estimates generally positive for whites and negative for African Americans.

CONCLUSION

Penile development is significantly influenced by race, and the impact of maternal phthalates on penile measurements also varies by race. Maternal phthalate exposure can adversely affect in utero penile growth and development, especially among African Americans.

Prenatal polybrominated diphenyl ethers exposure and anogenital distance in boys from a Shanghai birth cohort

BACKGROUND

Polybrominated diphenyl ethers (PBDEs) are major brominated flame retardant (BFR) chemicals with endocrine-disrupting properties. One small-scale study on humans has suggested that prenatal exposure to PBDEs is adversely related to anogenital distance (AGD) a sensitive marker for prenatal androgen exposure. The aim of the present study was to examine the associations between prenatal exposure to PBDEs and AGD among boys 0-4 years of age in a cohort study.

METHODS

In the Shanghai-Minhang Birth Cohort Study (S-MBCS), nine PBDE congeners were measured in cord plasma of 192 male infants. We measured anopenile distance (AGD_AP) and anoscrotal distance (AGD_AS) at birth, 6 months, 12 months, and 48 months of age. A total of 190 boys with neonatal concentrations of PBDEs (ng/g lipid) who had at-least one AGD measurement were included in our study. Information on potential confounding variables were collected through in-person interviews. Multiple linear regression models and generalized estimating equation (GEE) models were used to evaluate the associations between prenatal PBDEs concentrations and AGD.

RESULTS

Among the nine congeners, BDE-47 had the highest detection rate (83.68%) and the highest median concentration (0.18 ng/g lipid). Boys who had neonatal concentration of BDE-47 or Σ₄PBDEs (sum of BDE-47, BDE-99, BDE-100, and BDE-153) in the higher quartile generally had shorter AGD_AP and AGD_AS than those in the first quartile. Significant inverse associations were found between AGD_AS and fourth quartile BDE-47 levels among boys 12 months and 48 months of age (β = -5.57, 95% confidence interval (CI): -9.89, -1.25 for 12 month of age; β = -4.32, 95% CI: -8.18, -0.46 for 48 month of age). Inverse associations were also observed between AGD_AS and fourth quartile Σ₄PBDEs levels among boys 12 months of age (β = -5.13, 95% CI: -9.89, -1.25). In GEE models, similar patterns of association were also observed between BDE-47 and AGD_AS.

CONCLUSIONS

Our findings provide preliminary evidence that prenatal exposure to BDE-47 and Σ₄PBDEs, even at low environmental levels, may be associated with shorter AGD in boys. This data suggest that prenatal exposure to PBDEs may have adverse effects on male reproductive development. Further studies should be conducted to validate these results.

Maternal exposure to bisphenol A and anogenital distance throughout infancy: A longitudinal study from Shanghai, China

BACKGROUND

Bisphenol A (BPA) is one of the most common endocrine-disrupting compounds (EDCs) with a ubiquitous presence. Both animal and human studies have reported the association between maternal exposure to BPA and anogenital distance (AGD) in offspring. However, the results are conflicting and the longitudinal effect is unknown. We aimed to examine the effect of maternal exposure to BPA on AGD in offspring in a longitudinal birth cohort from birth to 1 year of age.

METHODS

BPA was assayed using urine samples collected at 12-16 gestational weeks from 982 pregnant participants who later delivered infants. Infants' AGDs (AGDap [anus-penis] and AGDas [anus-scrotum] for boys, AGDac [anus-clitoris] and AGDaf [anus-fourchette] for girls) were measured at birth, and at 6 and 12 months of age. Multiple linear regression analysis was conducted to examine the associations between maternal exposure to BPA and offspring's AGDs. Then generalized estimating equation (GEE) model was applied to make use of the repeated measurements of AGDs and examine the overall effect of maternal exposure to BPA.

RESULTS

Compared to boys with undetected maternal BPA, those with detected BPA were more likely to have shorter AGDap and AGDas at 6 and 12 months. However, the differences were statistically significant for AGDap and AGDas only at 12 months (2.87 and 4.12 mm shorter, respectively). In GEE models, similar patterns were observed. Boys in the higher quartiles were more likely to have shorter AGDap and AGDas than those in the first quartile. However, statistically significant differences were only observed in boys in the third quartile. For girls, these associations were not observed regardless of the timing of measurements (at birth, 6 months and 12 months).

CONCLUSIONS

Maternal exposure to BPA was associated with shortened AGDap and AGDas in boys at age 12 months but not in girls, which suggests a gender specific effect of BPA exposure on offspring's development.

Prenatal exposure to phthalates and phenols and infant endocrine-sensitive outcomes: The MIREC study

BACKGROUND

Anogenital distance (AGD) and the second to fourth finger (2D:4D) digit ratio may be early markers of in utero androgen exposure for the infant. Phthalates and phenols have been identified as endocrine disrupting chemicals.

OBJECTIVES

To study the association between prenatal exposure to phthalates, bisphenol A (BPA) and triclosan (TCS) and AGD and the 2D:4D digit ratios.

METHODS

Single spot urine samples were collected in the first trimester from the MIREC Study and analyzed for phthalates and phenols. Anogenital distance (n = 394) at birth and 2D:4D digit ratios (n = 420) at 6 months were measured in male and female infants. Associations between maternal concentrations of phenols and phthalate metabolites and these outcomes were estimated using multiple linear regression models.

RESULTS

In females, the anoclitoris distance (ACD) was negatively associated with mono-benzyl phthalate (MBzP) (β = -1.24; 95% CI -1.91, -0.57) and positively associated with mono-ethyl phthalate (MEP) (β = 0.65; 95% CI 0.12, 1.18) (masculinizing). In males, anopenile distance (APD) was positively associated with mono-n-butyl phthalate (MnBP) (β = 1.17; 95% CI 0.02, 2.32) and the molar sum of low molecular weight phthalates (ΣLMW). Female 2D:4D of the right hand was positively associated with MnBP and negatively with total BPA (masculinizing).

CONCLUSIONS

Significant associations were only observed for the long AGD metrics. Positive associations were observed between MnBP or LMW phthalates and APD in males. In females, prenatal MEP was associated with a masculinizing effect on ACD, while MBzP was associated with a feminizing effect. No significant associations were observed between prenatal phenols and AGD. Given the paucity of research on digit ratios and prenatal chemical exposures, it is difficult to say whether this metric will be a useful marker of prenatal androgen or anti-androgen exposure. Given the large number of associations examined, the statistical associations observed may have been due to Type 1 error. The inconsistencies in results between studies suggest that this issue is yet to be resolved.

Assessment of anogenital distance as a diagnostic tool in polycystic ovary syndrome

RESEARCH QUESTION

Is anogenital distance (AGD) a useful clinical tool for predicting polycystic ovarian syndrome (PCOS) and its main National Institutes of Health (NIH) phenotypes?

DESIGN

Case-control study conducted between September 2014 and May 2016 at the Department of Obstetrics and Gynecology of the University Clinical Hospital 'Virgen de la Arrixaca' in the Murcia region (south-eastern Spain). One hundred and twenty-six cases of PCOS and 159 controls without PCOS were included. AGD measurements were taken from the anterior clitoral surface to the upper verge of the anus (AGD_AC), and from the posterior fourchette to the upper verge of the anus (AGD_AF). Parametric and non-parametric tests and receiver operating characteristic (ROC) curves were used to assess associations between AGD and the presence of PCOS and its phenotypes.

RESULTS

AGD_AC, but not AGD_AF, was associated with PCOS and all its phenotypes (P-values < 0.001 to 0.048). The highest area under the curve (0.62; 95% confidence interval 0.55 to 0.71) was obtained for all PCOS with AGD_AC with a sensitivity and specificity of 50.0% and 73.0%, and positive and negative predictive value of 59.0% and 64.4%, respectively.

CONCLUSIONS

AGD_AC could moderately discriminate the presence of PCOS and may be a useful clinical tool.

Associations between hypospadias, cryptorchidism and anogenital distance: Systematic review and meta-analysis

Hypospadias and cryptorchidism are potential manifestations of testicular dysgenesis syndrome (TDS) at birth. Anogenital distance (AGD) has been presumed as an indicator related to endocrine disruptors proposed as one of the pathogenetic mechanisms underlying male reproductive disorders. In humans, recent studies have correlated AGD in boys to testicular anomalies. However, the associations between hypospadias, cryptorchidism and AGD remain inconsistent and have not been combined. Hence, we conducted a meta-analysis to assess gradations in the severity of the endocrine disruption in cryptorchidism or hypospadias by using AGD. A total of 2,119 boys from five birth cohort studies and two cross-sectional studies were subjected to meta-analysis. Random-effect model was used to calculate the standardised mean difference (SMD) of AGD. Our results reveal that boys with hypospadias or cryptorchidism have shorter AGD ([SMD, -2.63; 95% CI, -4.65 to -0.62] and [SMD, -0.69; 95% CI, -1.36 to -0.02]) respectively. There was no indication of a publication bias either from the result of Egger's test or Begg's test for hypospadias and cryptorchidism.

Anogenital distance in newborn daughters of women with polycystic ovary syndrome indicates fetal testosterone exposure

Polycystic ovary syndrome (PCOS) affects ~7% of reproductive age women. Although its etiology is unknown, in animals, excess prenatal testosterone (T) exposure induces PCOS-like phenotypes. While measuring fetal T in humans is infeasible, demonstrating in utero androgen exposure using a reliable newborn biomarker, anogenital distance (AGD), would provide evidence for a fetal origin of PCOS and potentially identify girls at risk. Using data from a pregnancy cohort (The Infant Development and Environment Study), we tested the novel hypothesis that infant girls born to women with PCOS have longer AGD, suggesting higher fetal T exposure, than girls born to women without PCOS. During pregnancy, women reported whether they ever had a PCOS diagnosis. After birth, infant girls underwent two AGD measurements: anofourchette distance (AGD-AF) and anoclitoral distance (AGD-AC). We fit adjusted linear regression models to examine the association between maternal PCOS and girls' AGD. In total, 300 mother-daughter dyads had complete data and 23 mothers reported PCOS. AGD was longer in the daughters of women with a PCOS diagnosis compared with daughters of women with no diagnosis (AGD-AF: β=1.21, P=0.05; AGD-AC: β=1.05, P=0.18). Results were stronger in analyses limited to term births (AGD-AF: β=1.65, P=0.02; AGD-AC: β=1.43, P=0.09). Our study is the first to examine AGD in offspring of women with PCOS. Our results are consistent with findings that women with PCOS have longer AGD and suggest that during PCOS pregnancies, daughters may experience elevated T exposure. Identifying the underlying causes of PCOS may facilitate early identification and intervention for those at risk.

Anogenital distance as a phenotypic signature through infancy

BackgroundAnogenital distance (AGD) has been suggested to represent a phenotypic signature reflecting in utero androgen action. However, it is not known whether an individual's AGD at birth correlates to the AGD later in life. We investigate correlations of AGD between 3 and 18 months of age and assess reproducibility of measurements.MethodsWe measured AGD from anus to scrotum (AGDas) and to penis (AGDap) in 407 boys, and to posterior fourchette (AGDaf) and clitoris (AGDac) in 282 girls. Each measure was repeated three times at 3 and 18 months of age, and some children were, furthermore, examined by two different examiners. We assessed age-related changes and reproducibility of measurements.ResultsAGD increased between the two examinations and correlated within the child. A large proportion of the observed variation in AGD was due to true differences between the children (AGDas: 62%, AGDap: 40%, AGDaf: 30%, AGDac: 21%), and measurement error due to between- and within-examiner variation was low.ConclusionsOur study showed that measures of AGD within a child correlated during infancy, especially in boys and particularly for AGD measured as the distance between anus and scrotum. A planned cohort follow-up through childhood and puberty will reveal whether AGD represents a phenotypic signature throughout life.

High Prenatal Exposure to Bisphenol A Reduces Anogenital Distance in Healthy Male Newborns

OBJECTIVE

To estimate the relationship between cord blood bisphenol A (BPA) levels and anogenital measurements in healthy newborns.

METHODS

Pregnancy and birth history, together with body mass and length data, anogenital measurements, penile measurements and cord blood samples were obtained from healthy newborns. Cord blood concentration of BPA was analyzed by sandwich enzyme-linked immunosorbent assays kit.

RESULTS

Among 130 healthy newborns (72 boys, 58 girls), mean anopenile distance was 45.2±6 mm and anoscrotal distance was 21.9±5.4 mm in boys; mean anoclitoral distance was 33.8±6.6 mm and mean anofourchette distance was 12.2±4.9 mm in girls. Mean cord blood BPA level was 4.75±2.18 ng/mL. 90th percentile value for cord blood BPA was 8.26 ng/mL and the analysis showed a statistically significant correlation between anoscrotal distance and cord blood BPA levels above the 90th percentile (p=0.047) in boys. The changes in anogenital distance in girls were not statistically significant.

CONCLUSION

We showed a significant association between high cord blood BPA levels and shortened anoscrotal distance in male newborns. However, this result should be interpreted with caution since there were no significant external genital abnormalities in our study group.

First and second trimester urinary metabolic profiles and fetal growth restriction: an exploratory nested case-control study within the infant development and environment study

BACKGROUND

Routine prenatal care fails to identify a large proportion of women at risk of fetal growth restriction (FGR). Metabolomics, the comprehensive analysis of low molecular weight molecules (metabolites) in biological samples, can provide new and earlier biomarkers of prenatal health. Recent research has suggested possible predictive first trimester urine metabolites correlating to fetal growth restriction in the third trimester. Our objective in this current study was to examine urinary metabolic profiles in the first and second trimester of pregnancy in relation to third trimester FGR in a US population from a large, multi-center cohort study of healthy pregnant women.

METHODS

We conducted a nested case-control study within The Infant Development and the Environment Study (TIDES), a population-based multi-center pregnancy cohort study. We identified 53 cases of FGR based on the AUDIPOG [Neonatal growth - AUDIPOG [Internet]. [cited 29 Nov 2016]. Available from: http://www.audipog.net/courbes_morpho.php?langue=en ] formula for birthweight percentile considering maternal height, age, and prenatal weight, as well as infant sex, gestational age, and birth rank. Cases were matched to 106 controls based on study site, maternal age (± 2 years), parity, and infant sex. NMR spectroscopy was used to assess concentrations of four urinary metabolites that have been previously associated with FGR (tyrosine, acetate, formate, and trimethylamine) in first and second trimester urine samples. We fit multivariate conditional logistic regression models to estimate the odds of FGR in relation to urinary concentrations of these individual metabolites in the first and second trimesters. Exploratory analyses of custom binned spectroscopy results were run to consider other potentially related metabolites.

RESULTS

We found no significant association between the relative concentrations of each of the four metabolites and odds of FGR. Exploratory analyses did not reveal any significant differences in urinary metabolic profiles. Compared with controls, cases delivered earlier (38.6 vs 39.8, p < 0.001), and had lower birthweights (2527 g vs 3471 g, p < 0.001). Maternal BMI was similar between cases and controls.

CONCLUSIONS

First and second trimester concentrations of urinary metabolites (acetate, formate, trimethylamine and tyrosine) did not predict FGR. This inconsistency with previous studies highlights the need for more rigorous investigation and data collection in this area before metabolomics can be clinically applied to obstetrics.

Systematic reviews and meta-analyses of human and animal evidence of prenatal diethylhexyl phthalate exposure and changes in male anogenital distance

Male reproductive alterations found in animals and humans following in utero phthalate exposure include decreased anogenital distance (AGD) and other reproductive-tract malformations. The aim of this investigation was to conduct systematic reviews of human and animal evidence of the effect of in utero exposure to diethylhexyl phthalate (DEHP) on anogenital distance (AGD) in males. PubMed, Embase, and Toxline were searched for relevant human and experimental animal studies on August 15, 2016. Search results were screened for relevance, and studies that met the inclusion criteria were evaluated for quality and data extracted for analysis. Confidence in the human and animal bodies of evidence was assessed and hazard conclusions reached by integrating evidence streams. The search yielded 6 relevant human studies and 19 animal studies. Meta-analysis of 5 human observational prospective cohort studies showed that increased maternal urinary concentrations of DEHP metabolites were associated with decreased AGD in boys (-4.07 [CI, -6.49 to -1.66] % decrease per log₁₀ rise in DEHP metabolites). Meta-analysis and meta-regression of the 19 experimental animal studies found reduced AGD with DEHP treatment, with a dose-response gradient, and with heterogeneity explained by species and strain. There is a moderate level of evidence from human investigations and a high level of data from animal studies that in utero exposure to DEHP decreases AGD. Based upon the available human and animal evidence, and consideration of mechanistic data, DEHP is presumed to be a reproductive hazard to humans on the basis of effects on AGD.

Influence of race on prenatal phthalate exposure and anogenital measurements among boys and girls

BACKGROUND

Select phthalates have antiandrogenic activity, which raises concern for adverse developmental outcomes given widespread exposure of pregnant women. Investigators have reported associations between maternal urinary phthalates and altered anogenital distance (AGD), a marker of in utero androgen activity, among offspring. However, data assessing the impact of race on these associations is sparse.

OBJECTIVES

To evaluate associations between prenatal phthalate exposure and AGD in a racially diverse newborn population.

METHODS

We prospectively collected second trimester urine from 187 African American and 193 white mothers, and used liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to measure eight phthalate metabolites and calculate molar sums. We measured anopenile (APD) and anoscrotal (ASD) distances of 171 boys and anoclitoral (ACD) and anofourchette (AFD) distances of 128 girls at delivery. We collected sociodemographic and clinical data from questionnaires and delivery records.

RESULTS

We identified a statistically significant inverse association for mono-2-ethylhexyl phthalate (MEHP) and APD in boys (B=-1.57mm, p=0.02), which was stronger for African Americans (B=-2.07mm, p=0.04) than for whites (B=-1.23mm, p=0.22), although the racial interaction was not statistically significant (p=0.56). We found a longer ASD for higher molar sums of dibutyl phthalate (∑DBP; B=0.99mm, p=0.04), with stronger associations for whites (B=1.30mm, p=0.04) than for African Americans (B=0.39mm, p=0.59), again without a statistically significant racial interaction (p=0.34). Among girls, we found inverse associations for tertiles of MEHP with AFD and ACD, and statistically significant race-based interactions, in which ACD was longer for whites and shorter for African Americans, following exposure to monoethyl phthalate (MEP; p=0.01) and ∑DBP (p=0.08).

CONCLUSIONS

Our findings suggest race and sex play important roles in phthalate-associated reproductive developmental toxicity, with important implications for designing future investigations and health interventions.

Systematic reviews and meta-analyses of human and animal evidence of prenatal diethylhexyl phthalate exposure and changes in male anogenital distance

Male reproductive alterations found in animals and humans following in utero phthalate exposure include decreased anogenital distance (AGD) and other reproductive-tract malformations. The aim of this investigation was to conduct systematic reviews of human and animal evidence of the effect of in utero exposure to diethylhexyl phthalate (DEHP) on anogenital distance (AGD) in males. PubMed, Embase, and Toxline were searched for relevant human and experimental animal studies on August 15, 2016. Search results were screened for relevance, and studies that met the inclusion criteria were evaluated for quality and data extracted for analysis. Confidence in the human and animal bodies of evidence was assessed and hazard conclusions reached by integrating evidence streams. The search yielded 6 relevant human studies and 19 animal studies. Meta-analysis of 5 human observational prospective cohort studies showed that increased maternal urinary concentrations of DEHP metabolites were associated with decreased AGD in boys (-4.07 [CI, -6.49 to -1.66] % decrease per log₁₀ rise in DEHP metabolites). Meta-analysis and meta-regression of the 19 experimental animal studies found reduced AGD with DEHP treatment, with a dose-response gradient, and with heterogeneity explained by species and strain. There is a moderate level of evidence from human investigations and a high level of data from animal studies that in utero exposure to DEHP decreases AGD. Based upon the available human and animal evidence, and consideration of mechanistic data, DEHP is presumed to be a reproductive hazard to humans on the basis of effects on AGD.

Dichlorodiphenyltrichloroethane exposure and anogenital distance in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) birth cohort study, South Africa

Dichlorodiphenyltrichloroethane (DDT) is used for malaria control by 10 countries, nine of which are in Africa. Technical DDT contains various isomers with 65-80% insecticidal p,p'-DDT and 15-21% o,p'-DDT, an estrogenic chemical, while the persistent metabolite of p,p'-DDT, dichlorodiphenyldichloroethylene (p,p'-DDE), is an antiandrogen. In utero antiandrogenic exposure reduces anogenital distance in animal models and the anal position index in a single study. This study examined the associations between mother's serum DDT and DDE levels at delivery and anogenital distance in their children at birth and age 1 year. Data were collected as part of the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), a birth cohort study located in rural South Africa. DDT and DDE concentrations were measured in blood samples collected from 752 mothers at delivery. Anogenital distance measurements, taken at birth (n = 671) and age 1 year (n = 674), included anofourchette and anoclitoral distances in girls, and anoscrotal and anopenile lengths in boys. We also measured anococcygeal and coccyx-fourchette distances in girls, while in boys, we measured anococcygeal and coccyx-scrotal distances as well as penile length and penile width. The anal position index is calculated for both sexes as anoscrotal/coccyx-scrotal in boys and anofourchette/coccyx-fourchette in girls. We found no associations between p,p'-DDT/-DDE or o,p'-DDT and anogenital distance measurements at birth in either boys or girls. At 1 year, o,p'-DDE was negatively associated with anofourchette in girls (β =-1.32 mm, 95% confidence interval (CI) = -2.27, -0.38) and positively associated with penile width in boys (β = 0.30 mm, 95% CI = 0.00, 0.60). The results do not suggest an overt antiandrogenic or estrogenic effect on anogenital distance after long-term DDT exposure. These weak associations may be due to chance.