Anogenital distance is determined during early gestation in humans

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.

Development and verification of machine learning model based on anogenital distance, penoscrotal distance, and 2D:4D finger ratio before puberty to predict hypospadias classification

Objectives

To describe the anatomical abnormalities of hypospadias before puberty using current commonly used anthropometric index data and predict postoperative diagnostic classification.

Methods

Children with hypospadias before puberty who were initially treated at Sichuan Provincial People's Hospital from April 2021 to September 2022 were selected. We recorded their preoperative penoscrotal distance, anogenital distance, 2D:4D finger ratio, and postoperative hypospadias classification. The receiver operating character curve was used for univariate analysis of the diagnostic predictive value of each index for hypospadias classification in the training set. Binary logistic regression, random forest, and support vector machine models were constructed. In addition, we also prospectively collected data from October 2022 to September 2023 as a test set to verify the constructed machine learning models.

Results

This study included 389 cases, with 50 distal, 167 midshaft, and 172 proximal cases. In the validation set, the sensitivity of the binary LR, RF, and SVM was 17%, 17% and 0% for identifying the distal type, 61%, 55% and 64% for identifying the midshaft type, and 56%, 60% and 48% for identifying the proximal type, respectively. The sensitivity of the three-classification RF and SVM models was 17% and 17% for distal type, 64% and 73% for midshaft type, 60% and 60% for proximal type, respectively. In the Testing set, the sensitivity of the binary LR, RF and SVM was 6%, 0% and 0% for identifying the distal type, 64%, 55% and 66% for identifying the midshaft type, and 48%, 62% and 39% for identifying the proximal type, respectively. The sensitivity of the three-classification RF and SVM models was 12% and 0% for distal type, 57% and 77% for midshaft type, and 65% and 53% for proximal type, respectively. Compared with binary classification models, the sensitivity of the three-classification models for distal type was not improved.

Conclusion

Anogenital distance and penoscrotal distance have a favorable predictive value for midshaft and proximal hypospadias, among which AGD2, with higher test efficiency and stability, is recommended as the preferred anogenital distance indicator. The 2D:4D finger ratio (RadioL, RadioR) has little predictive value for hypospadias classification.

Anogenital distance in a cohort of 169 infant boys with uni- or bilateral cryptorchidism including 18 boys with vanishing testes

STUDY QUESTION

Do different boys with different types of cryptorchidism exhibit different anogenital distances (AGDs)?

SUMMARY ANSWER

Length of AGD seemed to differ in different groups of patients with cryptorchidism.

WHAT IS KNOWN ALREADY

AGD, which is used as an indicator of prenatal androgen action, tends to be shorter in boys with cryptorchidism compared to unaffected boys. Shorter AGDs have also been reported in boys with hypospadias, in men with poor semen quality, and in men with testicular cancer.

STUDY DESIGN, SIZE, DURATION

A prospective descriptive cohort study was performed using data from consecutively selected boys with cryptorchidism (n = 169) operated in a single center over a period of 3 years (September 2019 to October 2022).

PARTICIPANTS/MATERIALS, SETTING, METHODS

AGD was measured in 169 infant boys, at 3 to 26 months of age, during anesthesia with a vernier caliper measuring the distance from the anus to the base of the scrotum (AGDAS) and from the anus to the anterior base of the penis (AGDAP) in two body positions according to the methods by 'The Infant Development and the Environment Study' (TIDES) and 'Cambridge Baby Growth Study', resulting in four mean values per patient (TIDES AGDAS/AP and Cambridge AGDAS/AP). Normal values for AGD by age were set by our hospital Department of Growth and Reproduction based on a large cohort of healthy infant boys (n = 1940). Testicular biopsies were performed at orchidopexy as a clinical routine. The germ cell number (G/T) and type Ad spermatogonia number (AdS/T) per cross-sectional tubule of at least 100 and 250 tubules, respectively were measured and related to normal samples. Blood samples were obtained by venipuncture for measuring serum LH, FSH, and inhibin B. They were analyzed in our hospital Department of Growth and Reproduction where the normal reference was also established. Correlations between the four mean AGD measurements for each boy were evaluated by Spearman rank correlation analyses. The AGD measurement of every boy was transferred to the multiple of the median (MoM) of the normal AGD for age and named MoM AGD.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 104 boysoperated for unilateral, and 47 boys operated for bilateral, undescended testes, whereas 18 boys had vanished testis including one boy with bilateral vanished testes. Only 6% of cases with vanished testes had a MoM AGD higher than the normal median compared to 32% with undescended testes (P < 0.05). MoM AGD increased with the age at surgery for boys with vanished testis (Spearman r = 0.44), but not for boys with undescended testes (Spearman r = 0.14). Boys with bilateral cryptorchidism had longer AGDs and more often had hypogonadotropic hypogonadism than boys with unilateral cryptorchidism (P < 0.005) and (P < 0.000001).

LIMITATIONS, REASONS FOR CAUTION

Although being the largest published material of AGD measurements of infant boys with cryptorchidism, one limitation of this study covers the quite small number of patients in the different groups, which may decrease the statistical power. Another limitation involves the sparse normal reference material on G/T and AdS/T. Finally, there are currently no longitudinal studies evaluating AGD from birth to adulthood and evaluating childhood AGD in relation to fertility outcome. Our study is hypothesis generating and therefore the interpretation of the results should be regarded as exploratory rather than reaching definite conclusions.

WIDER IMPLICATIONS OF THE FINDINGS

The study findings are in agreement with literature as the total included group of boys with cryptorchidism exhibited shorter than normal AGDs. However, new insights were demonstrated. Boys with vanished testis had shorter AGDs compared to unaffected boys and to boys with undescended testes. This finding challenges the current concept of AGD being determined in 'the masculinization programming window' in Week 8 to 14 of gestation. Furthermore, boys with bilateral cryptorchidism had longer AGDs and more often had hypogonadotropic hypogonadism than boys with unilateral cryptorchidism, suggesting that the lack of fetal androgen in hypogonadotropic hypogonadism is not that significant.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used and no competing interests are declared.

TRIAL REGISTRATION NUMBER

The trial was not registered in an ICMJE-recognized trial registry.

Generation of South Indian Data for Normal Clitoral Dimensions and Anogenital Ratio in Term Neonates

Introduction

Assessment of genitalia is an important part of the neonatal examination. Regional, racial, and ethnic variations in phallic length have been documented. Clitoral dimensions may also show similar variations. Normal values for neonatal clitoral measurements may help the pediatrician/neonatologist to accurately diagnose clitoromegaly and underlying etiology to guide appropriate investigations. Data on clitoral measurements is limited with only one study from India (Kolkata). Hence we aimed in this study to generate south Indian data on neonatal clitoral dimensions, anogenital distance, and anogenital ratio. Two hundred and fifty two hemodynamically stable term female neonates without ambiguous genitalia/vulval masses born in a community hospital. Hospital-based cross-sectional study. 1. To measure clitoral dimensions, anogenital distance, and anogenital ratio in female neonates. 2. To correlate clitoral dimensions, anogenital distance, and ratio with anthropometric measurements, gestational age, and maternal comorbidities.

Methods

Measurements were recorded using a digital vernier caliper, under strict aseptic precautions with labia majora gently separated and the baby held in a frog-leg position. Clitoral length, width, and anogenital distance were measured and anogenital ratio and clitoral index were calculated.

Results

In term neonates, the mean ± SD of clitoral length (CL), clitoral width (CW), anogenital ratio (AGR) were 6.34 ± 1.75 mm, 6.39 ± 1.27 mm and 0.39 ± 0.05, respectively. The 3rd and 97th centiles for mean clitoral length were 3.55 and 9.93 mm, for mean clitoral width were 3.37 and 8.35 mm, and for AGR were 0.28 and 0.48, respectively. These clitoral dimensions in south Indian neonates were higher than those from East India (Kolkata), lower than Nigerian babies, and similar to Israeli neonates. Mean CL and CW had no statistical correlation with birth weight, gestational age, head circumference, or length in term neonates. A significant correlation was noted between pregnancy-induced hypertension and mean clitoral width, and between gestational diabetes and AGR.

Conclusion

Normative values for clitoral dimensions (length and width) and AGR for south Indian term female neonates have been established. 97th centiles of 9.93 mm (CL) and 8.35 mm (CW) and 0.48 mm (AGR) may be used as practical cut-offs to diagnose clitoromegaly and virilization. Clitoral measurements had no statistical correlation with birth weight, gestational age, or anthropometry. Clitoral measurements exhibit ethnic and racial differences, thus emphasizing the importance of regional cut-offs and need for more studies from different parts of India on CL.

The anogenital ratio as an indicator of reproductive performance in dairy heifers

The anogenital distance (AGD) is considered a marker for prenatal androgen exposure and fertility in multiple species including humans. In dairy cattle, it is described as the length between the center of the anus and the clitoral base (AGDc). However, in other species, the distance from the center of the anus to the dorsal commissure of the vulva (AGDv) is also considered to be a predictor for fertility traits, as well as the anogenital ratio (AGR, defined as [AGDv/AGDc]*100). The primary aim of the present study was to assess whether AGDv and AGR can be used as an indicator for reproductive performance in dairy heifers. Additionally, the relation between AGDv and AGDc and the correlation with other body measurements were explored. Data of 656 Holstein Friesian heifers at an age of 13.5 ± 1.08 months were analyzed. Respective means of 62.9 ± 8.20 mm (AGDv) and 107.6 ± 9.27 mm (AGDc) were recorded. The mean AGR ratio was calculated as 58.6 ± 6.75%, varying from 37.3 to 79.6%. The age of the heifers was not associated with any of the AGD measurements nor the ratio. Except for a very low correlation between heart girth and AGDc (r = 0.09, P < 0.05), both AGDs were largely uncorrelated with other body measurements. Linear regression models revealed that AGDc was not associated with any of the recorded fertility parameters. However, results revealed a negative association between AGDv and AGR and reproductive performance: heifers with a short AGDv and small AGR were younger at first AI (P ≤ 0.003) and at conception (P = 0.004). Based on ROC curve analyses, AGDv was the best indicator for pregnancy to first AI, with a threshold estimated at 65.3 mm. The pregnancy rate at first AI was 72.4% in heifers with a short AGDv (<65.3 mm, n = 413) compared to 61.7% in heifers with a long AGDv (≥65.3 mm, n = 243). Hence, short-AGDv heifers had 63% higher odds to conceive at first AI compared to their long-AGDv counterparts (P = 0.004). Additionally, an AGR threshold of 59,6% was determined: heifers with a small AGR (<59.6%) had 44% higher odds to be pregnant at first AI compared to heifers with an AGR ≥59.6%. Results of the present study suggest to consider AGDv and AGR as potential indicators for reproductive performance in dairy heifers. The latter implies that it is relevant to measure both AGDc and AGDv in future studies. The absence of correlation between body- and AGD-measurements furthermore suggests that AGD sizes are rather pre-than postnatally determined.

Longer anogenital distance in female fetus of diabetic and obese pregnant women

OBJECTIVE

Previous studies revealed that prenatal exposure to androgen excess such as polycystic ovary syndrome (PCOS) is associated with offspring's anogenital distance (AGD) length, and AGD is a biomarker of intrauterine androgen exposure. This study aims to investigate a possible relationship of fetal AGD with maternal diabetes and obesity, and to evaluate whether AGD predicts the fetal androgen exposure related to diabetes and obesity in female fetus. This study is the first to focus on the relationship between offspring's AGD and maternal diabetes and obesity.

MATERIALS AND METHODS

This is a prospective study investigating 218 pregnant women (125 in control group and 93 in study group). Fetal AGD was measured from the center of anus to the posterior convergence of the fourchette by ultrasound. Multivariate linear regression analysis was applied to assess the association of the fetal AGD length with maternal diabetes and obesity.

RESULTS

The control patients had significantly shorter fetal AGD (mean:10.7 mm, P < 0.001) compared to diabetic, obese and diabetic obese patients (mean: 12.6 mm, 12.8 mm and 12.9 mm, respectively). The results of regression analysis showed that both maternal diabetes and obesity were significantly correlated with longer AGD in female fetus. The results confirmed also that offspring's AGD measurement in utero by ultrasound is feasible and reliable.

CONCLUSION

The study findings suggest that both maternal diabetes and obesity are associated with intrauterine androgenic milieu during pregnancy, and fetal AGD may be used as a biomarker to predict this effect. This may provide important advantages in terms of early detection of reproductive system abnormalities related to prenatal androgen exposure.

Mini-puberty testosterone and infant autistic traits

Background

Levels of steroid hormones in the first three months of life, a period referred to as 'mini-puberty', are one of the earliest physiological differences between typical males and females postnatally. Autistic traits also show consistent typical sex differences in later infancy, after the 18th month of life. Previous studies have shown prenatal testosterone is associated with later levels of autistic traits. Studies testing if postnatal testosterone levels are associated with autistic traits have reported null results. No studies to date have investigated mini-puberty longitudinally or tested for interactions with baseline sex differences or familial likelihood of autism.

Methods

The 'Cambridge Human Imaging and Longitudinal Development Study' (CHILD) is a prospective enriched cohort study in Cambridge, UK. It includes physiological measurements in early infancy, as well as neurodevelopmental follow-ups over the first two years of life. A subset of the cohort also includes children with a family history of autism (a diagnosed parent or sibling). Salivary testosterone levels were assessed at two time-points, just after the 2nd and 6th month of life. Autistic traits were measured using the Quantitative Checklist of Autism in Toddlers (Q-CHAT) when the children were 18 months of age.

Results

Salivary testosterone levels were significantly higher during 'mini-puberty' in the 2nd and 3rd month of life, compared to after the 6th month of life, in both males and females. There was no significant sex difference at either time-point. Log-transformed testosterone levels were not associated with autistic traits (Q-CHAT). There was no interaction effect with infant sex, autism family history or baseline testosterone levels after mini-puberty (at >6 months of age).

Conclusion

Both male and female infants have elevated levels of salivary testosterone during mini-puberty but in this relatively small sample this was not associated with their later autistic traits at 18 months or their family history of autism. This suggests that prenatal rather than postnatal testosterone levels are more relevant for understanding the causes of autism. Future studies should test these relationships in larger samples.

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.

Anogenital Distance and Endometriosis: Results of a Case-Control Study

AGD is the distance measured from the anus to the genital tubercle. Recent evidence suggests that a shorter AGD, a sensitive biomarker of the prenatal hormonal environment, could be associated with higher endometriosis risk. However, studies investigating AGD in affected women are scanty. We have set up a case-control study recruiting nulliparous women (aged 18-40 years) with endometriosis between 2017 and 2018. Cases were 90 women with a surgical or with a current nonsurgical diagnosis of endometriosis (n = 45 deep infiltrating endometriosis (DIE), and n = 45 ovarian endometrioma (OMA)). Controls were 45 asymptomatic women referring for periodical gynaecological care and without a previous diagnosis of endometriosis. They were matched to cases for age and BMI. For each woman, two measures were obtained using a digital calliper: AGD_AC, from the clitoral surface to the upper verge of the anus, and AGD_AF, from the posterior fourchette to the upper verge of the anus. Each distance was derived from the mean of six measurements acquired from two different gynaecologists. The mean ± SD AGD_AC in women with DIE, OMA and without a diagnosis of endometriosis was 76.0 ± 12.1, 76.1 ± 11.1 and 77.8 ± 11.4 mm, respectively (p = 0.55). The mean ± SD AGD_AF in women with DIE, OMA and without a diagnosis of endometriosis was 22.8 ± 5.0, 21.7 ± 9.0 and 23.7 ± 7.8 mm, respectively (p = 0.38). Our study failed to find an association between AGD and the presence of endometriosis. AGD does not seem to represent a reliable indicator of the presence of endometriosis to be used in clinical practice.

Associations of maternal anthropometrics with newborn anogenital distance and the 2:4 digit ratio

STUDY QUESTION

Are maternal anthropometrics associated with anogenital distance (AGD) and 2:4 digit ratio (2:4D) in newborns?

SUMMARY ANSWER

Select maternal anthropometrics indicative of obesity or increased adiposity are associated with elongated AGD in daughters.

WHAT IS KNOWN ALREADY

Excessive maternal weight or adiposity before or in early pregnancy may impact child reproductive, and other hormonally mediated, development. AGD and 2:4D are proposed markers of in utero reproductive development.

STUDY DESIGN, SIZE, DURATION

This study includes 450 mother/newborn dyads participating in the Illinois Kids Development Study (I-KIDS), a prospective pregnancy cohort from Champaign-Urbana, IL, USA. Participants included in the current study enrolled between 2013 and 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Most mothers in this study were college-educated (82%) and non-Hispanic White (80%), and 55% were under- or normal weight before pregnancy. Pregnant women aged 18-40 years reported pre-pregnancy weight and height to calculate pre-pregnancy BMI. At 8-15 weeks gestation, we measured waist and hip circumference, and evaluated weight, % body fat, visceral fat level, % muscle and BMI using bioelectrical impedance analysis. Within 24 h of birth, we measured newborn 2nd and 4th left/right digits to calculate the 2:4D. In daughters, we measured AGDAF (anus to fourchette) and AGDAC (anus to clitoris). In sons, we measured AGDAS (anus to scrotum) and AGDAP (anus to base of the penis).

MAIN RESULTS AND THE ROLE OF CHANCE

Select maternal anthropometrics were positively associated with AGD in newborn daughters, but not sons. For example, AGDAC was 0.73 mm (95% CI: 0.15, 1.32) longer for every interquartile range (IQR) increase in pre-pregnancy BMI and 0.88 mm (95% CI: 0.18, 1.58) longer for every IQR increase in hip circumference, whereas AGDAF was 0.51 mm (95% CI: 0.03, 1.00) and 0.56 mm (95% CI: 0.03, 1.09) longer for every IQR increase in hip and waist circumference, respectively. Quartile analyses generally supported linear associations, but additional strong associations emerged in Q4 (versus Q1) of maternal % body fat and visceral fat levels with AGDAC. In quartile analyses, we observed only a few modest associations of maternal anthropometrics with 2:4D, which differed by hand (left versus right) and newborn sex. Although there is always the possibility of spurious findings, the associations for both measures of female AGD were consistent across multiple maternal anthropometric measures, which strengthens our conclusions.

LIMITATIONS, REASONS FOR CAUTION

Our study sample was racially and ethnically homogenous, educated and relatively healthy, so our study may not be generalizable to other populations. Additionally, we may not have been powered to identify some sex-specific associations, especially for 2:4D.

WIDER IMPLICATIONS OF THE FINDINGS

Increased maternal weight and adiposity before and in early pregnancy may lengthen the female AGD, which warrants further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

This publication was made possible by the National Institute for Environmental Health Sciences (NIH/NIEHS) grants ES024795 and ES022848, the National Institute of Child Health and Human Development grant R03HD100775, the U.S. Environmental Protection Agency grant RD83543401 and National Institute of Health Office of the Director grant OD023272. Its contents are solely the responsibility of the grantee and do not necessarily represent the official views of the US EPA or NIH. Furthermore, the US EPA does not endorse the purchase of any commercial products or services mentioned in the publication. This project was also supported by the USDA National Institute of Food and Agriculture and Michigan AgBioResearch. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Sexual Function in Women With Differences of Sex Development or Premature Loss of Gonadal Function

BACKGROUND

Previous studies have suggested that sexual function may be compromised in women born with differences of sex development (DSD) or early loss of gonadal function.

AIM

To describe sexual function and sexual wellbeing in women with complete androgen insensitivity syndrome (CAIS), complete gonadal dysgenesis (GD) and premature ovarian insufficiency (POI) in relation to gynecological measures and in comparison with unaffected women.

METHODS

A cross sectional study including 20 women with CAIS, 8 women with 46,XY GD, 8 women with 46,XX GD, 21 women with POI, and 62 population-derived controls. Study participants underwent gynecological examination for anatomical measurements and evaluation of tactile sensitivity. They responded to the validated Sexual Activity Log (SAL), Profile of Female Sexual Function (PFSF), and the Personal Distress Scale (PDS).

RESULTS

The women with CAIS, XY GD, XX GD and POI showed overall satisfying sexual function in comparison to unaffected age-matched population female controls with a median of 1 to 2 satisfying sexual episodes per week among both the patients and the controls depending on available partner. Women with CAIS had shorter vagina and smaller clitoris and women with XY GD had a significantly shallower vagina in comparison to controls. Clitoral width was also significantly smaller among women with XX GD compared to controls. However, results showed overall good genital touch sensitivity with no significant differences between groups.

CLINICAL IMPLICATIONS

Women with DSD or POI can be informed on overall satisfactory sexual function and normal genital touch sensitivity.

STRENGTHS & LIMITATIONS

The strength is the use of age-matched population-based controls to these rare conditions of DSD and POI. Limitations are the nonresponder rate of recruited controls, as well as the small groups of women with DSD.

CONCLUSION

Women with differences of sex development or early loss of gonadal function show overall good sexual well-being, however clinicians have to make efforts to optimize caretaking and treatment to ensure good sexual quality of life for all patients. Engberg H, Strandqvist A, Berg E, et al., Sexual Function in Women With Differences of Sex Development or Premature Loss of Gonadal Function. J Sex Med 2022;19:249-256.

The use of anogenital distance as a non-invasive predictor of seminal quality in captive squirrel monkey (Saimiri collinsi Osgood 1961)

BACKGROUND

Anogenital distance is considered a non-invasive measure to assess the development and functionality of sexual organs in different animal species. Hence, this measurement could potentially be used during the selection of non-human primates for reproductive biotechnology programs. The aim of this study was to assess the correlation between anogenital distance and reproductive parameters in captive Saimiri collinsi.

METHODS

Eight mature S. collinsi males were evaluated. Body weight, reproductive hormone levels, testicular volume, and seminal parameters were determined, and their relationship with anogenital distance measurements was assessed.

RESULTS

Anogenital distance was correlated with seminal volume, sperm motility, vigor, and plasma membrane integrity, but not with body weight, reproductive hormones, and testicular volume.

CONCLUSION

The determination of anogenital distance is a non-invasive method to predict seminal quality. This procedure has the advantage of providing andrologic information without a negative impact on animal welfare.

Prenatal Exposure to Cigarette Smoke and Anogenital Distance at 4 Years in the INMA-Asturias Cohort

Smoking by women is associated with adverse pregnancy outcomes such as spontaneous abortion, preterm delivery, low birth weight, infertility, and prolonged time to pregnancy. Anogenital distance (AGD) is a sensitive biomarker of prenatal androgen and antiandrogen exposure. We investigated the effect of smoking and passive smoke exposure during pregnancy on anogenital distance in offspring at 4 years in the INMA-Asturias cohort (Spain). Women were interviewed during pregnancy to collect information on tobacco consumption, and anogenital distance was measured in 381 children: Anoscrotal distance in boys and anofourchetal distance in girls. We also measured maternal urinary cotinine levels at 32 weeks of pregnancy. We constructed linear regression models to analyze the association between prenatal smoke exposure and anogenital distance and adjusted the models by relevant covariates. Reported prenatal smoke exposure was associated with statistically significant increased anogenital index (AGI), both at week 12 of pregnancy (β = 0.31, 95% confidence interval: 0.00, 0.63) and at week 32 of pregnancy (β = 0.31, 95% confidence interval: 0.00, 0.63) in male children, suggesting altered androgenic signaling.

Effect of prenatal phthalate exposure on the association of maternal hormone levels during early pregnancy and reproductive markers in infants at the age of 3 months

Phthalates belong to the endocrine-disrupting chemicals, altering the hormonal balance in humans during pregnancy with further effects on the reproductive system. This study aimed to investigate the associations between maternal hormone levels during early pregnancy (≤15th week of pregnancy) and reproductive markers in infant boys (n = 37; 61.67 %; average age 3.51 ± 0.73 months) and girls (n = 23; 38.33 %; average age 3.30 ± 0.33 months) concerning prenatal exposure to phthalates. We used high-performance liquid chromatography, tandem mass spectrometry (HPLC-MS/MS), and electro-chemiluminescence immunoassay to quantify urinary concentrations of phthalates and serum concentrations of hormones, respectively. In Mother-Infant Study Cohort (PRENATAL), we observed positive and negative correlations between infants' reproductive markers and phthalate metabolites (p ≤ 0.05). Next, we noticed associations between the penile length and maternal testosterone (β = 0.464) and estradiol levels (β = -0.365) with increasing significance after adjustment to maternal mono-n-butyl phthalate (MnBP) and monobenzyl phthalate (MBzP) (p ≤ 0.05). We observed a positive association (β = 0.337) between penile width and maternal testosterone with increasing significance after adjustment to maternal mono-iso-butyl phthalate (MiBP) (p ≤ 0.05). In a group of girls, we reported a negative association between ACD/AFD ratio and maternal follicle-stimulating hormone (FSH) and estradiol levels with increasing significance after adjustment to maternal monoethyl phthalate (MEP), MnBP, and mono(hydroxy-iso-butyl) phthalate (OH-MiBP). Our results highlight that prenatal phthalate exposure may modulate the effects of maternal hormone levels during early pregnancy on infants' reproductive markers.

Endocrine-sensitive physical endpoints in newborns: ranges and predictors

BACKGROUND

In neonates, endocrine-sensitive physical endpoints, including breast and reproductive tissues, may reflect effects of fetal environmental exposure. Studies using standardized measurement techniques that describe demographic and clinical variability in these endpoints are lacking.

METHODS

Three hundred and eighty-eight healthy term newborns <3 days old were evaluated, 69% African American and 25% White. Measures included breast bud diameter, anogenital distance (AGD), stretched penile length (SPL), and testicular volume (TV).

RESULTS

Breast buds were larger in females than males bilaterally (right: 13.0 ± 4.0 vs. 12.0 ± 4.0 mm, p = 0.008; left: 13.0 ± 4.0 vs. 11.0 ± 3.0 mm, p < 0.001). Breast bud size correlated positively with gestational age (regression coefficient = 0.46 ± 0.12 mm, p < 0.001) and weight Z-score (0.59 ± 0.24 mm, p = 0.02), and negatively with White race (-1.00 ± 0.30 mm, p = 0.001). AGD was longer in males (scrotum-to-anus) than females (fourchette-to-anus) (21.0 ± 4.0 vs. 13.0 ± 2.0 mm, p < 0.001) and did not differ by race. SPL was shorter in White infants (35.0 ± 5.0 vs. 36.0 ± 5.0 mm, p = 0.04). Median TV was 0.5 cm³, and larger in White males (odds ratio 1.71, 95% confidence interval: 1.02-2.88) CONCLUSIONS: This study provides a range of physical measurements of endocrine-sensitive tissues in healthy infants from the United States, and the associations with demographic and clinical characteristics.

IMPACT

This study reports physical measurements for endocrine-sensitive endpoints in healthy US newborns, including breast buds, AGD, SPL, and TV. Associations of measurements to demographic and clinical factors (including race, gestational age, and newborn length and weight) are presented. Contemporary ranges and identification of predictive factors will support further study on effects of pre- and postnatal exposures to endocrine-sensitive tissues in the infant.

Prenatal smoke exposure is associated with increased anogenital distance in female infants: a prospective case-control study

OBJECTIVES

To investigate the effects of maternal smoking during pregnancy on newborn infants' anogenital distance (AGD).

METHODS

Fifty-six female and sixty-four male newborn infants from mothers who smoked during pregnancy were included in this study. A control group for each sex was selected from infants whose mothers had no active or passive (in either the household or the workplace) smoke exposure before or during pregnancy. Questionnaire data on maternal demographic characteristics and information about cigarette use were collected. We assessed genital anthropometry which included AGD for both male and female neonates, and stretched penile length (SPL), penile girth for males within the first 48 h after birth. AGD measurements were also normalized according to birth weight (AGD/weight in grams), length (AGD/height in millimeters), and ponderal index [AGD/(weight in grams/height in cubic centimeters)]. Anogenital index (AGI) was calculated by dividing the AGD by cube root of birth weight.

RESULTS

In female infants, prenatal smoke exposure was associated with significantly increased weight-adjusted AGD (p=0.03). There was also a significant correlation between mothers' daily smoking rates and weight-adjusted AGD (r=0.27/p=0.03). In male infants, fetal smoke exposure was not associated with any AGD measurements, SPL and penile girth.

CONCLUSIONS

A significant increase in weight-adjusted AGD in female infants exposed to maternal smoking may be an indicator of antenatal androgen exposure and may pose a risk for short and long-term endocrine, metabolic and behavioral problems.

Stretched penile length and its associations with testosterone and infertility

Background

Male infertility can be associated with secondary sexual characteristics, hypogonadism, and several findings in the examination of external genitalia. We sought to identify if stretched penile length (SPL) is associated with infertility or baseline testosterone.

Methods

We performed a retrospective review of all males age 18–59 presenting to a Men’s health clinic from 2014 to 2017. SPL of patients with infertility were compared to patients with any other complaint. Patients with Peyronie’s disease, prior penile surgery, prostatectomy, on testosterone replacement, clomiphene or β-hCG were excluded from our study. Baseline characteristics were compared between the two groups (infertile vs. other). Linear regression was used to assess the association between infertility and testosterone with SPL after adjusting for patient age, BMI, and race. Scatterplot was used for correlation between testosterone and SPL.

Results

Six hundred and sixty-four men were included in our study (161 infertile, 503 other). The unadjusted mean SPL in the infertile group was 12.3 cm compared to 13.4 cm in the other group (P<0.001). The significance remained when adjusted for age, BMI, testosterone and race (12.4 vs. 13.3, P<0.001). Mean total testosterone in the infertile group was not significantly different than the other group (414 vs. 422, P=0.68). Infertile men were younger than the other group (33.2 vs. 42.1 years, P<0.001). BMI did not significantly differ (28.9 vs. 28.9 kg/m², P=0.57). There was a weak positive correlation between testosterone and penile size in both the infertile group (r=0.20, P=0.01) and the other group (r=0.24, P<0.001).

Conclusions

Though SPL differed amongst our groups, adult testosterone levels did not. If developmental levels of testosterone exposure accounted for some of the differences in SPL between our two groups, these variations did not persist into adulthood. It remains unknown if reduced length is a result of genetic or congenital factors associated with infertility. Further investigation is needed to better understand the association of shorter SPL with male infertility.

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.

Hypothetical roadmap towards endometriosis: prenatal endocrine-disrupting chemical pollutant exposure, anogenital distance, gut-genital microbiota and subclinical infections

BACKGROUND

Endometriosis is a gynaecological hormone-dependent disorder that is defined by histological lesions generated by the growth of endometrial-like tissue out of the uterus cavity, most commonly engrafted within the peritoneal cavity, although these lesions can also be located in distant organs. Endometriosis affects ~10% of women of reproductive age, frequently producing severe and, sometimes, incapacitating symptoms, including chronic pelvic pain, dysmenorrhea and dyspareunia, among others. Furthermore, endometriosis causes infertility in ~30% of affected women. Despite intense research on the mechanisms involved in the initial development and later progression of endometriosis, many questions remain unanswered and its aetiology remains unknown. Recent studies have demonstrated the critical role played by the relationship between the microbiome and mucosal immunology in preventing sexually transmitted diseases (HIV), infertility and several gynaecologic diseases.

OBJECTIVE AND RATIONALE

In this review, we sought to respond to the main research question related to the aetiology of endometriosis. We provide a model pointing out several risk factors that could explain the development of endometriosis. The hypothesis arises from bringing together current findings from large distinct areas, linking high prenatal exposure to environmental endocrine-disrupting chemicals with a short anogenital distance, female genital tract contamination with the faecal microbiota and the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis.

SEARCH METHODS

We performed a search of the scientific literature published until 2019 in the PubMed database. The search strategy included the following keywords in various combinations: endometriosis, anogenital distance, chemical pollutants, endocrine-disrupting chemicals, prenatal exposure to endocrine-disrupting chemicals, the microbiome of the female reproductive tract, microbiota and genital tract, bacterial vaginosis, endometritis, oestrogens and microbiota and microbiota-immune system interactions.

OUTCOMES

On searching the corresponding bibliography, we found frequent associations between environmental endocrine-disrupting chemicals and endometriosis risk. Likewise, recent evidence and hypotheses have suggested the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis. Hence, we can envisage a direct relationship between higher prenatal exposure to oestrogens or estrogenic endocrine-disrupting compounds (phthalates, bisphenols, organochlorine pesticides and others) and a shorter anogenital distance, which could favour frequent postnatal episodes of faecal microbiota contamination of the vulva and vagina, producing cervicovaginal microbiota dysbiosis. This relationship would disrupt local antimicrobial defences, subverting the homeostasis state and inducing a subclinical inflammatory response that could evolve into a sustained immune dysregulation, closing the vicious cycle responsible for the development of endometriosis.

WIDER IMPLICATIONS

Determining the aetiology of endometriosis is a challenging issue. Posing a new hypothesis on this subject provides the initial tool necessary to design future experimental, clinical and epidemiological research that could allow for a better understanding of the origin of this disease. Furthermore, advances in the understanding of its aetiology would allow the identification of new therapeutics and preventive actions.

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.

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.

Endocrine-disrupting chemicals: implications for human health

Since reports published in 2015 and 2016 identified 15 probable exposure-outcome associations, there has been an increase in studies in humans of exposure to endocrine-disrupting chemicals (EDCs) and a deepened understanding of their effects on human health. In this Series paper, we have reviewed subsequent additions to the literature and identified new exposure-outcome associations with substantial human evidence. Evidence is particularly strong for relations between perfluoroalkyl substances and child and adult obesity, impaired glucose tolerance, gestational diabetes, reduced birthweight, reduced semen quality, polycystic ovarian syndrome, endometriosis, and breast cancer. Evidence also exists for relations between bisphenols and adult diabetes, reduced semen quality, and polycystic ovarian syndrome; phthalates and prematurity, reduced anogenital distance in boys, childhood obesity, and impaired glucose tolerance; organophosphate pesticides and reduced semen quality; and occupational exposure to pesticides and prostate cancer. Greater evidence has accumulated than was previously identified for cognitive deficits and attention-deficit disorder in children following prenatal exposure to bisphenol A, organophosphate pesticides, and polybrominated flame retardants. Although systematic evaluation is needed of the probability and strength of these exposure-outcome relations, the growing evidence supports urgent action to reduce exposure to EDCs.

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 perfluoroalkyl substances and newborn anogenital distance in a Canadian cohort

Exposure to the man-made chemicals perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) is widespread. These perfluoroalkyl substances (PFASs) have been associated with androgenic endocrine-disrupting properties; however, the evidence is equivocal and few human studies have examined the association between prenatal exposure to PFASs and markers of androgenic endocrine disruption such as changes in anogenital distance (AGD). In the MIREC cohort, PFOA, PFOS and PFHxS were analyzed in first trimester maternal plasma. AGD was measured in 205 male and 196 female newborns. The change in estimate procedure was used to identify confounders by sex and AGD in multiple linear regression models. Geometric mean plasma concentrations (95% CI) for PFOA, PFOS and PFHxS were 1.71 (1.61, 1.81), 4.40 (4.18, 4.64) and 1.15 (1.06, 1.25) μg/L, respectively. A one-unit increase in natural log transformed PFOA was associated with a 1.36 mm (95% CI 0.30, 2.41) increase in anoscrotal distance, adjusting for household income, active smoking status during pregnancy and gestational age. However, when examined by quartiles, a non-monotonic pattern was observed with wide confidence intervals. No consistent patterns were observed between maternal PFAS concentrations and female AGDs. This study found no clear evidence that maternal plasma concentrations of PFOS, PFOA or PFHxS were associated with shorter infant anogenital distance in males or any change in AGD in females. Whether the positive association observed between longer anoscrotal distance and PFOA is real or would have any long-lasting effect on the reproductive health of males is unknown and needs to be investigated further.

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.

Evaluation of ambiguous genitalia

PURPOSE OF REVIEW

To provide a framework for the evaluation of ambiguous genitalia.

RECENT FINDINGS

The most pressing evaluation of ambiguous genitalia is assessment for life-threatening causes such as salt-wasting congenital adrenal hyperplasia (CAH) or syndromes with underlying anomalies such as neurologic or cardiac malformations. A multidisciplinary team, including specialists in Gynecology, Endocrinology, Urology, Genetics, Clinical Psychology/Psychiatry, Radiology, Nursing, Neonatology, and Pediatric Surgery, should be involved. Each patient should be approached in an individualized manner to assign sex of rearing in the most expeditious yet thoughtful means possible.As knowledge on the natural history of sex preference and fertility of individuals with ambiguous genitalia increases, controversy regarding the indication for and timing of genital surgery continues. Considerations include gender identity, future fertility, malignancy risk, infection prevention, and functional anatomy for sexual activity.

SUMMARY

The evaluation of ambiguous genitalia should involve a multidisciplinary team. A combination of history taking, physical examination, laboratory evaluation, and radiologic assessment can assist with the diagnosis. Care should be taken to emphasize karyotypic sex is not equivalent to gender and to use caution with regards to irreversible medical and surgical therapies which may impact fertility and sexual function and nonconform with future sex identity.

A clinical algorithm to diagnose differences of sex development

The diagnosis and management of children born with ambiguous genitalia is challenging for clinicians. Such differences of sex development (DSDs) are congenital conditions in which chromosomal, gonadal, or anatomical sex is atypical. The aetiology of DSDs is very heterogenous and a precise diagnosis is essential for management of genetic, endocrine, surgical, reproductive, and psychosocial issues. In this Review, we outline a step-by-step approach, compiled in a diagnostic algorithm, for the clinical assessment and molecular diagnosis of a patient with ambiguity of the external genitalia on initial presentation. We appraise established and emerging technologies and their effect on diagnosis, and discuss current controversies.