Placental Weight and Male Genital Anomalies: A Nationwide Danish Cohort Study

Associations between synthetic phenols, phthalates, and placental growth/function: a longitudinal cohort with exposure assessment in early pregnancy

STUDY QUESTION

Is exposure to environmental chemicals associated with modifications of placental morphology and function?

SUMMARY ANSWER

Phthalates, a class of ubiquitous chemicals, showed an association with altered placental weight, placental vascular resistance (PVR), and placental efficiency.

WHAT IS KNOWN ALREADY

Only a few epidemiological studies have assessed the effects of phenols and phthalates on placental health. Their results were affected by exposure measurement errors linked to the rapid excretion of these compounds and the reliance on a limited number of spot urine samples to assess exposure.

STUDY DESIGN SIZE DURATION

A prospective mother-child cohort, with improved exposure assessment for non-persistent chemicals, recruited participants between 2014 and 2017. Sample size ranged between 355 (placental parameters measured at birth: placental weight and placental-to-fetal weight ratio (PFR): a proxy for placental efficiency) and 426 (placental parameters measured during pregnancy: placental thickness and vascular resistance).

PARTICIPANTS/MATERIALS SETTING METHODS

Phenols (four parabens, two bisphenols, triclosan, and benzophenone-3), 13 phthalate metabolites, and two non-phthalate plasticizer metabolites were measured in within-subject pools of repeated urine samples collected during the second and third trimesters of pregnancy (median = 21 samples/trimester/woman). Placental thickness and PVR were measured during pregnancy. The placenta was weighed at birth and the PFR was computed. Both adjusted linear regression and Bayesian Kernel Machine Regression were used to evaluate associations between phenols and phthalates (alone or as a mixture) and placental parameters. Effect modification by child sex was also investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

Several phthalate metabolites were negatively associated with placental outcomes. Monobenzyl phthalate (MBzP) concentrations, during the second and third trimesters of pregnancy, were associated with a decrease in both placental weight at birth (β = -20.1 g [95% CI: -37.8; -2.5] and β = -17.4 g [95% CI: -33.2; -1.6], for second and third trimester, respectively) and PFR (β = -0.5 [95% CI: -1, -0.1] and β = -0.5 [95% CI: -0.9, -0.1], for the second and third trimester, respectively). Additionally, MBzP was negatively associated with PVR during the third trimester (β= -0.9 [95% CI: -1.8; 0.1]). Mono-n-butyl phthalate (MnBP), was negatively associated with PVR in both trimesters (β = -1.3, 95% CI: [-2.3, -0.2], and β = -1.2, 95% CI: [-2.4, -0.03], for the second and third trimester, respectively). After stratification for child sex, Σ diisononyl phthalate (DiNP) (either second or third-trimester exposures, depending on the outcomes considered) was associated with decreased PVR in the third trimester, as well as decreased placental weight and PFR in males. No associations were observed for phenol biomarkers.

LIMITATIONS REASONS FOR CAUTION

False positives cannot be ruled out. Therefore, chemicals that were associated with multiple outcomes (MnBP and DiNP) or reported in existing literature as associated with placental outcomes (MBzP) should be considered as the main results.

WIDER IMPLICATIONS OF THE FINDINGS

Our results are consistent with in vitro studies showing that phthalates target peroxisome proliferator-activated receptor γ, in the family of nuclear receptors involved in key placental development processes such as trophoblast proliferation, migration, and invasion. In addition to placental weight at birth, we studied placental parameters during pregnancy, which could provide a broader view of how environmental chemicals affect maternal-fetal exchanges over the course of pregnancy. Our findings contribute to the increasing evidence indicating adverse impacts of phthalate exposure on placental health.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the French Research Agency-ANR (MEMORI project ANR-21-CE34-0022). The SEPAGES cohort was supported by the European Research Council (N°311765-E-DOHaD), the European Community's Seventh Framework Programme (FP7/2007-206-N°308333-892 HELIX), the European Union's Horizon 2020 research and innovation programme (N° 874583 ATHLETE Project, N°825712 OBERON Project), the French Research Agency-ANR (PAPER project ANR-12-PDOC-0029-01, SHALCOH project ANR-14-CE21-0007, ANR-15-IDEX-02 and ANR-15-IDEX5, GUMME project ANR-18-CE36-005, ETAPE project ANR-18-CE36-0005-EDeN project ANR-19-CE36-0003-01), the French Agency for Food, Environmental and Occupational Health & Safety-ANSES (CNAP project EST-2016-121, PENDORE project EST-2016-121, HyPAxE project EST-2019/1/039, PENDALIRE project EST-2022-169), the Plan Cancer (Canc'Air project), the French Cancer Research Foundation Association de Recherche sur le Cancer-ARC, the French Endowment Fund AGIR for chronic diseases-APMC (projects PRENAPAR, LCI-FOT, DysCard), the French Endowment Fund for Respiratory Health, the French Fund-Fondation de France (CLIMATHES-00081169, SEPAGES 5-00099903, ELEMENTUM-00124527). N.J. was supported by a doctoral fellowship from the University Grenoble Alpes. V.M. was supported by a Sara Borrell postdoctoral research contract (CD22/00176), granted by Instituto de Salud Carlos III (Spain) and NextGenerationEU funds. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT02852499.

Lethality of Birth Defects in Live Born Infants Categorized by Gestational Age and Birth Weight

OBJECTIVE

This study aimed to describe lethality of birth defects (BDs) in newborns categorized by gestational age and birth weight and to identify BDs associated with prematurity.

STUDY DESIGN

Live born infants (n = 16,452) with isolated BDs classified by severity, and 42,511 healthy controls were assigned to categories: adequate growth, preterm, or small for gestational age (SGA). Proportion of cases and BDs' lethality rates were obtained by category and compared with controls.

RESULTS

Overall fewer malformed than nonmalformed infants were of adequate growth, while the opposite occurred in the preterm and SGA categories where gastroschisis and esophageal atresia were among the most outstanding defects. For most severe BDs, the early neonatal death rate was higher than control values in all categories; for mild defects, except cleft lip in the preterm category, they did not differ. Diaphragmatic hernia showed the highest lethality values, while those of spina bifida were among the lowest. Talipes, hypospadias, and septal heart defects were mild defects significantly associated with prematurity.

CONCLUSION

Although reasons, such as induced preterm delivery of fetuses with certain anomalies, could partially account for their high prematurity rates, susceptibility to preterm birth might exist through underlying mechanisms related with the defects. The identification of BDs associated with prematurity should serve to improve measures that prevent preterm birth especially of fetuses at risk.

KEY POINTS

· Some BDs predispose to prematurity.. · Prematurity is an additional risk factor for mortality in infants with mild defects.. · Lethality values should be adjusted by gestational age and birth weight..

Structural causal model with expert augmented knowledge to estimate the effect of oxygen therapy on mortality in the ICU

Recent advances in causal inference techniques, more specifically, in the theory of structural causal models, provide the framework for identifying causal effects from observational data in cases where the causal graph is identifiable, i.e., the data generation mechanism can be recovered from the joint distribution. However, no such studies have been performed to demonstrate this concept with a clinical example. We present a complete framework to estimate the causal effects from observational data by augmenting expert knowledge in the model development phase and with a practical clinical application. Our clinical application entails a timely and essential research question, the effect of oxygen therapy intervention in the intensive care unit (ICU). The result of this project is helpful in a variety of disease conditions, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) patients in the ICU. We used data from the MIMIC-III database, a widely used health care database in the machine learning community with 58,976 admissions from an ICU in Boston, MA, to estimate the oxygen therapy effect on morality. We also identified the model's covariate-specific effect on oxygen therapy for more personalized intervention.

Hypospadias: A Comprehensive Review Including Its Embryology, Etiology and Surgical Techniques

Hypospadias is among the most prevalent urogenital malformations in male newborns. It is characterized by the displacement of the urethral meatus to the ventral side of the penis, an aberrant ventral curve of the penis referred to as "chordee," and an abnormally arranged foreskin with a "hood" found dorsally and lacking foreskin ventrally. Patients may have an extra genitourinary abnormality based on the area of the lesion. In around 70% of cases, the urethral meatus is positioned distally to the shaft, representing a milder form of the disease. The remaining 30% of cases are located proximally, are more complicated, and require further evaluation. Although the origin of hypospadias is mostly obscure, several suggestions exist about genetic susceptibility and hormonal factors. The objective of hypospadias restoration is to restore aesthetic and functional regularity, and surgery is currently advised at a young age, mostly between six and 18 months. At any age, hypospadias can be repaired with an equivalent risk of complications, functional outcomes, and aesthetic outcomes. However, the best age of treatment is still undetermined. Even though the long-term effects on appearance and sexual function are usually good, males may be less likely to make the first move after rectification. Also, people who have hypospadias treated are twice as likely to have problems with their lower urinary tract. These problems can last for years after the initial repair.

Elevated prenatal maternal sex hormones, but not placental aromatase, are associated with child neurodevelopment

Fetal exposure to testosterone may contribute to vulnerability for autism spectrum disorder (ASD). It is hypothesized that placental aromatase prevents fetal exposure to maternal testosterone, however, this pathway and the implications for child neurodevelopment have not been fully explored. We examined the relationships between prenatal maternal testosterone and estradiol at 19.2 ± 1.3 weeks, cord blood testosterone and estradiol at birth, placental aromatase mRNA expression, and neurodevelopment using the Social Communication Questionnaire (SCQ), the Behavioral Assessment System for Children, 3rd Edition (BASC-3), and the Empathizing Quotient for Children (EQ-C) at 4.5-6.5 years of age in a sample of 270 Nulliparous-Mothers-to-be (nuMoM2b) study participants. Maternal testosterone levels were positively associated with SCQ scores, but the association was not significant after adjusting for maternal age at delivery, nor was there a significant interaction with sex. Maternal estradiol levels were negatively associated with BASC-3 Clinical Probability scores among males (n = 139). We report a significant interaction effect of cord blood testosterone and fetal sex on both total SCQ scores and t-scores on the Developmental Social Disorders subscale. Placental aromatase was not associated with any neurodevelopmental or hormone measure, but under conditions of low placental aromatase expression, high maternal testosterone was positively associated with SCQ scores in males (n = 46). No other associations between hormone levels and neurodevelopment were significant. Our findings provide a foundation for further investigation of the mechanisms through which maternal sex hormones and placental steroidogenesis may affect fetal hormone production and neurobehavior.

Abnormal placental cord insertion, hypertensive disorders of pregnancy and birth length may be involved in development of hypospadias in male fetuses

Objectives

Hypospadias is a congenital disease characterized by morphological abnormalities of the penis, including abnormal urethral opening and penile flexion, which cause urination disorders and/or sexual intercourse difficulty. Various factors have been suggested to cause this anomaly, but evidence concerning risk factors causing this anomaly is insufficient. We evaluated the etiology of hypospadias in Japan using the Common Database of the National Hospitals' Neonatal study group.

Study design

We retrospectively evaluated 7,865 male neonates registered in the NICU Common Database of the National Hospitals' Neonatal study group. The subjects were divided into two groups by the presence (n = 43) or absence (n = 7,822) of hypospadias. Statistical analyses were performed to compare nominal variables between the groups by Fisher's direct establishment calculation method and logistic regression analyses.

Results

A univariate analysis showed significant between‐group differences in hypertensive disorders in pregnancy (odds ratio [OR]: 4.02, 95% confidence interval [CI]: 1.95–7.90), placental weight <−1.28 standard deviation (SD; OR: 5.06, 95% CI: 2.45–10.32), abnormal placental cord insertion (OR: 4.7, 95% CI: 2.62–9.76), birth length <−2SD (OR: 10.56, 95% CI: 5.00–21.1) and birth weight <−2SD (OR: 8.17, 95% CI: 4.17–15.68). A multivariate analysis showed a significant between‐group difference in hypertensive disorders of pregnancy (adjusted OR [AOR]: 2.30, 95% CI: 1.09–4.85), abnormal placental cord insertion (AOR: 3.69, 95% CI: 1.83–7.44) and birth length <−2SD (AOR: 3.44, 95% CI: 1.26–9.42).

Conclusion

Abnormal placental cord insertion, hypertensive disorders of pregnancy and birth length may be involved in hypospadias development in male neonates in conjunction with placental dysfunction in early pregnancy.

Placental weight Z-score and pubertal timing: A population-based cohort study

BACKGROUND

The placenta provides nutrients, oxygen, and hormonal support for adequate fetal growth and development of the hormonal axes, which are important for pubertal timing later in life.

OBJECTIVES

We investigated if an indicator of poor placental function, low gestational age-specific Z-score for placental weight at birth, was associated with earlier pubertal timing.

METHODS

The study is based on a population-based cohort of 15 195 singleton boys and girls (68% of 22 439 invited) born 20 to 43 weeks of gestation (2000-2003) nested within the Danish National Birth Cohort. Placental Z-score was estimated from data collected at birth. Between 2012 and 2018, the children returned half-yearly web-based questionnaires from age of 11 years on status of the pubertal milestones: Tanner stages, voice break, first ejaculation, menarche, acne, and axillary hair. We estimated adjusted monthly differences in mean age at attaining the pubertal milestones and pubertal timing overall with placental Z-score continuously and as restricted cubic splines. Further, we explored whether growth by birthweight Z-score and body mass index Z-score around 7 years mediated the associations.

RESULTS

Placental Z-score was positively associated with age at attaining most of the pubertal milestones in girls, particularly for age at menarche, but not in boys. Effect sizes were modest, and when combining all pubertal milestones, one standard deviation increase in placental Z-score was associated with 0.5 months (95% confidence interval [CI] 0.2, 0.9) later pubertal timing overall in girls. The associations in girls were largely mediated through fetal growth.

CONCLUSIONS

Assuming that placental Z-score correlates with placental function, these findings suggest that placental dysfunction (low placental Z-score) advances pubertal timing in girls slightly by reducing fetal growth. Future studies need to evaluate whether placental weight sufficiently captures intrauterine growth of importance for pubertal development and search for other potential candidates reflecting placental function.

Occupational exposure to endocrine-disrupting chemicals and other parental risk factors in hypospadias and cryptorchidism development: a case-control study

AIM OF THE STUDY

Endocrine-disrupting chemicals (EDCs) are exogenous agents that are capable of altering the endocrine system functions, including the regulation of developmental processes. The aim of this study was to investigate the association between EDC exposure and other parental factors in the etiology of hypospadias and cryptorchidism.

METHODS

A case-control study was conducted. Cases (n = 210) were infants aged between 6 months and 14 years diagnosed with hypospadias or cryptorchidism who attended the authors' hospital over a period of 18 months, and controls (n = 210) were infants within the same range of age and without any urological disorders who attended the outpatient clinic of the same hospital during the same time period. Their selection was independent of exposures. Data on parental occupational exposure to EDCs and other sociodemographic variables were collected through face-to-face interviews and systematically for both cases and controls. Crude and adjusted odds ratios (ORs) were estimated to control for confounding with their 95% confidence interval (CI) by means of logistic regressions. Specifically, three final models of a dichotomous outcome were constructed: one for cryptorchidism, one for hypospadias, and the third considering both malformations together. The Hosmer-Lemeshow test was used to assess the goodness of fit of the models. Their discriminatory accuracy (DA) was ascertained by estimating their areas under the receiver operating characteristic curves area under the curve (AUC) along with their 95% CI.

RESULTS

Associations were found between advanced maternal age (OR adjusted = 1.82; 95% CI: 1.14-2.92), mother's consumption of anti-abortives (OR = 5.40; 95% CI: 1.40-38.5) and other drugs (OR = 2.02; 95% CI: 1.31-3.16) during pregnancy, maternal and paternal occupational exposure to EDCs (OR = 4.08; 95% CI: 2.03-8.96 and OR = 3.90; 95% CI: 2.41-6.48, respectively), fathers smoking (OR = 2.0; 95% CI: 1.33-2.99), and fathers with urological disorders (OR = 2.31; 95% CI: 1.15-4.90). Maternal and paternal high educational level could be protective of cryptorchidism (OR = 0.47; 95% CI: 0.28-0.76 and OR = 0.63; 95% CI: 0.42-0.93, respectively). The DA of the models for the whole sample (AUC = 0.75; 95% CI: 0.70-0.79) for cryptorchidism (AUC = 0.76; 95% CI: 0.71-0.82) and for hypospadias (AUC = 0.75; 95% CI: 0.69-0.81) was moderately high.

CONCLUSIONS

Advanced age, some parental occupational exposure to EDCs, some drug consumption, smoking, and the father's history of urological disorders may increase risk and predict the developments of these malformations. Studies with higher samples sizes are needed to assess associations between individual EDC occupational exposures and drugs and these malformations.

Fetal Heart Defects and Measures of Cerebral Size

OBJECTIVES

To estimate the association between fetal congenital heart defects (CHDs) and measures of brain size throughout pregnancy, from the end of the first trimester to birth.

STUDY DESIGN

The cohort consisted of all fetuses scanned in Western Denmark in 2012 and 2013. Anthropometric measures in fetuses with isolated CHDs diagnosed within 12 months after birth were compared with those in the fetuses without CHDs. Z-scores standardized to gestational age were calculated for first trimester biparietal diameter, second trimester head circumference, fetal weight, birthweight, head circumference, and placental weight.

RESULTS

We obtained data from 63 349 pregnancies and identified 295 fetuses with isolated CHDs (major n = 145; minor n = 150). The first trimester mean biparietal diameter Z-scores were not different between those with and those without CHDs. The head circumference mean Z-score difference was -0.13 (95% CI, -0.24 to -0.01; P = .03) in the second trimester and -0.22 (95% CI, -0.35 to -0.09; P < .001) at birth. Fetuses with univentricular physiology or tetralogy of Fallot showed the most pronounced compromise in cerebral size.

CONCLUSIONS

Our results suggest that the brain alterations inducing an increased risk of impaired neurodevelopment in children with CHDs begin during pregnancy. Although fetuses with univentricular physiology or tetralogy of Fallot exhibited the most pronounced compromise in cerebral size, we recommend neurodevelopmental follow-up for all children with CHDs.

Impaired serum inhibin-B and number of germ cells in boys with cryptorchidism following heavily gestational maternal smoking

PURPOSE

A meta-analysis including 11,900 cases showed that maternal gestational smoking was associated with increased risk of cryptorchidism. The aim of study was to investigate whether a hormone profile of cryptorchid boys and a supplementing histopathological evaluation of testicular biopsies could add detailed knowledge to the impact of maternal gestational smoking on pathogenesis of cryptorchidism.

METHODS

601 cryptorchid boys aged 4 months to 14 years old were included. Because normal hormones have a pronounced age dependency, we compared results from boys whose mothers had smoked heavily (>10 cigarettes/day) during pregnancy with age matched cryptorchid controls of nonsmoking mothers (1:6). We studied: birthweight, germ-cell number/tubular cross section, frequency of germ cells positive for placental-like alkaline phosphatase (PLAP), gonadotropins and inhibin-B.

RESULTS

501 boys were sons of nonsmokers, 72 boys of intermittent smokers and 28 boys of heavy smokers. 39%, 44% and 61% respectively had bilateral cryptorchidism. Compared to age-matched cryptorchid controls of nonsmoking mothers, sons of heavy smokers had lower birthweight (p = 0.006), germ-cell number/tubular cross section (p = 0.009), frequency of germ cells positive for PLAP (p = 0.037) and inhibin-B (p = 0.042).

CONCLUSIONS

All findings could be associated with placental dysfunction with altered human chorionic gonadotropin production well described in women smoking during pregnancy.

TYPE OF STUDY

Prognosis study (prospective cohort study with >80% follow-up).

LEVEL OF EVIDENCE

Level 1.

Maternal Diabetes Mellitus and Genital Anomalies in Male Offspring: A Nationwide Cohort Study in 2 Nordic Countries

BACKGROUND

Pre-existing diabetes has been associated with an increased risk of congenital malformations overall, but studies on genital anomalies in boys are conflicting and possible causal mechanisms are not well understood. Previous studies have mainly assessed pregestational and gestational diabetes in combination. Yet considering the vulnerable time windows for the genital anomalies, associations could well differ between types of diabetes and between the 2 genital anomalies and we therefore aimed to study this further.

METHODS

A population-based cohort study of 2,416,246 singleton live-born boys from Denmark (1978-2012) and Sweden (1987-2012) was carried out using Danish and Swedish register-based data. Using Cox regression models, we estimated hazard ratios for hypospadias and cryptorchidism according to maternal diabetes. We considered type and severity of diabetes, as well as timing of diagnosis in relation to birth.

RESULTS

Pregestational type 1 diabetes was associated with a higher risk of both genital anomalies. The highest risks were seen for boys of mothers with diabetic complications (hazard ratio for hypospadias = 2.33 [95% confidence interval, 1.48, 3.66] and hazard ratio for cryptorchidism = 1.92 [95% confidence interval, 1.39, 2.65]). Gestational diabetes was associated with slightly increased risks of both genital anomalies.

CONCLUSIONS

These results are consistent with the hypothesis that poor glycemic control may interfere with fetal genital development in the critical early period of organogenesis. Given the widespread and increasing occurrence of diabetes, these results are of public health importance.

Prenatal Exposure to Select Phthalates and Phenols and Associations with Fetal and Placental Weight among Male Births in the EDEN Cohort (France)

BACKGROUND

The placenta performs crucial physiological functions to ensure normal fetal development. Few epidemiological studies investigated placental weight sensitivity to phthalates and phenols.

OBJECTIVE

Our goal was to explore whether maternal exposure to select phthalates and phenols is associated with changes in placental weight at birth and in placental–to–birth weight ratio (PFR).

METHODS

Placental weight and birth weight were available for 473 mother–son pairs in the EDEN (Etude des Déterminants pré et postnatals du développement et de la santé de l'Enfant) cohort for whom 9 phenols (4 parabens, 2 dichlorophenols, triclosan, benzophenone-3, bisphenol A) and 11 phthalate metabolites were measured in spot urine samples collected between weeks 23 and 29 of gestation. We used adjusted Elastic Net penalized regression models (ENET) to select biomarkers associated with placental weight, birth weight and PFR. Unpenalized effect estimates were then obtained by fitting linear regression models simultaneously adjusted for the ENET-selected biomarkers and a priori chosen confounders.

RESULTS

The multipollutant ENET model for placental weight retained four biomarkers: triclosan and monocarboxy-isononyl phthalate (MCNP), which were negatively associated with placental weight, and benzophenone-3 and the sum of parabens, which were positively associated with this outcome. The ENET model for PFR retained two phthalate metabolites [MCNP and monocarboxy-isooctyl phthalate (MCOP)], which were negatively associated with this outcome.

DISCUSSION

The positive association between the sum of parabens and placental weight was consistent with results of a previous study among 49 male births. Our results provide preliminary evidence of possible associations between other compounds such as triclosan, benzophenone-3, MCNP, and MCOP and both placental weight and PFR. These associations were not reported in previous studies and should be seen as hypothesis generating. Studies relying on repeated assessments of exposure in prospective mother–child cohorts are needed to substantiate the plausibility of the hypotheses generated by our results. https://doi.org/10.1289/EHP3523.

Relationship between birth weight to placental weight ratio and major congenital anomalies in Japan

Recent studies have indicated that birth weight to placental weight (BW/PW) ratio is related to perinatal outcomes, but the effect of congenital abnormalities on BW/PW ratio remains unclear. We performed this study to elucidate correlations between BW/PW ratio and congenital abnormalities. Subjects were 735 singleton infants born at 34–41 weeks of gestation admitted to our center between 2010 and 2016. Of these, 109 infants (15%) showed major congenital anomalies. Major congenital anomalies and subgroups were diagnosed according to European Surveillance of Congenital Anomalies criteria. The primary outcome was the association between BW/PW ratio and major congenital anomaly, and secondary outcomes were the distribution pattern of BW/PW ratio with major anomalies and by major anomaly subgroups in each categorization (<10th percentile, 10–90th percentile, or >90th percentile) of BW/PW ratio. BW/PW ratio was not associated (P = 0.20) with presence (adjusted mean BWPW ratio = 5.02, 95% confidence interval [CI] 4.87–5.18) or absence (adjusted mean BW/PW ratio = 4.91, 95%CI 4.85–4.97) of major anomalies, after adjusting for gestational age and sex. Proportions of infants with major anomalies according to BW/PW ratio categories were as follows: 12% in <10th percentile, 15% in 10–90th percentile, and 25% in >90th percentile of BW/PW ratio. Among major anomalies of the nervous system, congenital heart defects, and orofacial clefts, BW/PW ratio showed equally distributed trend across the three BW/PW ratio categories, but showed unequally distributed trend for anomalies of the digestive system, other anomalies/syndromes, or chromosomal abnormalities. BW/PW ratio was not associated with major congenital anomaly, and was distributed diffusely according to major anomaly subgroups. Major anomalies may tend to aggregate in the 90th percentile of the BW/PW ratio.

Placental Weight and Risk of Cryptorchidism and Hypospadias in the Collaborative Perinatal Project

Cryptorchidism and hypospadias are the most common congenital anomalies of the genitourinary tract in males, but their etiology remains unclear. Placental insufficiency has been suggested to be linked to both conditions. Placental weight is a commonly used proxy measure for placental insufficiency; thus, we examined placental weight and other placental characteristics in relation to cryptorchidism and hypospadias in the Collaborative Perinatal Project, a US mother-child cohort study. Pregnant women were recruited between 1959 and 1965. The analysis contrasted boys with cryptorchidism (n = 413) and boys with hypospadias (n = 145) with boys without cryptorchidism (n = 23,799) and boys without hypospadias (n = 22,326). Odds ratios and 95% confidence intervals were calculated using unconditional logistic regression. In categorical analyses in which the middle tertile was the referent, cryptorchidism was inversely associated with placental weight (odds ratio = 0.66, 95% confidence interval: 0.46, 0.95) among white boys and positively associated with the lowest tertile of placental weight among black boys (odds ratio = 1.70, 95% confidence interval: 1.11, 2.59). We conclude that lower placental weight may be related to risk of cryptorchidism. Further investigation of placental functioning may offer insights into the etiology of cryptorchidism.

Accuracy of the hypospadias diagnoses and surgical treatment registrations in the Danish National Patient Register

Purpose

The Danish National Health registers provide a valuable data source that offers unique opportunities for observational research, including studies on the congenital anomaly hypospadias. The accuracy of the diagnosis and surgical treatment registration of hypospadias in the Danish National Patient Register (DNPR) remains unknown.

Patients and methods

We randomly sampled 500 patients diagnosed with hypospadias in the DNPR from January 1, 1995 to December 31, 2012. Among these, 384 patients were also registered with surgical treatment for hypospadias. Medical records were collected and reviewed independently by two investigators. Any classification disagreements were resolved by consensus. Using the medical records as the gold standard, we estimated positive predictive values (PPVs) with 95% confidence intervals (CIs) for the hypospadias diagnoses and surgical treatment registrations overall, as well as for the clinical subtypes.

Results

We were able to retrieve medical records for 463 (92.6%) patients with hypospadias diagnoses and for 329 (85.7%) patients registered with surgical treatment. Presence of hypospadias was confirmed in 450 of 463 patients, yielding an overall PPV (95% CI) of 97.6% (95.8%–98.7%). For subtypes of hypospadias, the PPVs ranged between 37.5% and 72.7%. For surgical treatment of hypospadias, the overall PPV was 99.7% (97.9%–99.9%).

Conclusion

The validity of the registration of hypospadias diagnoses as well as surgical treatment for hypospadias in the DNPR is overall very high. For the specific subtypes of hypospadias diagnoses codes and the specific surgical treatment codes, the PPVs are lower and cautious use is warranted. However, the DNPR remains a valuable tool for future observational research on hypospadias.

Maternal endometriosis and genital malformations in boys: a Danish register-based study

OBJECTIVE

To investigate the association between maternal endometriosis and occurrence of the genital anomalies cryptorchidism and hypospadias in sons.

DESIGN

Population-based cohort study.

SETTING

Not applicable.

PATIENT(S)

All live-born singleton boys born from 1978 to 2012.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Cryptorchidism and hypospadias in boys based on information from the Danish National Patient Register.

RESULT(S)

The study included 1,073,026 live-born singleton boys. A total of 6,443 boys were sons of women diagnosed with endometriosis before pregnancy. Altogether, 27,342 boys were diagnosed with cryptorchidism, of whom 16,446 had corrective surgery. Hypospadias was diagnosed in 4,853 boys. As compared with unexposed boys, a tendency towards a slightly higher occurrence of cryptorchidism was observed among boys of women with endometriosis (adjusted hazard ratio [aHR] 1.18; 95% confidence interval [CI], 0.97, 1.44). When stratified by medically assisted reproduction (MAR) technologies, the association was slightly stronger among boys born to women with endometriosis who had conceived via MAR, yet it remained moderate and statistically insignificant (aHR 1.27; 95% CI, 0.86; 1.88). When women who conceived with MAR were excluded, the association between endometriosis and cryptorchidism disappeared. For hypospadias, we observed no association, either in the main analysis or the stratified analysis.

CONCLUSION(S)

The findings from this register-based study do not provide strong evidence for a higher occurrence of the studied genital anomalies among boys of women with endometriosis.

Maternal Overweight and Obesity and Genital Anomalies in Male Offspring: A Population-Based Swedish Cohort Study

BACKGROUND

Overweight and obese pregnant women face higher risk of several critical birth outcomes, including an overall increased risk of congenital abnormalities. Only few studies have focused on associations between maternal overweight and the genital anomalies in boys, cryptorchidism and hypospadias, and results are inconclusive.

METHODS

We performed a population-based cohort study and assessed the associations between maternal body mass index (BMI) in early pregnancy and occurrence of cryptorchidism and hypospadias. All live-born singleton boys born in Sweden from 1992 to 2012 were included. From the Swedish Patient Register, information on cryptorchidism and hypospadias was available. Data were analysed using Cox proportional hazards regression adjusted for potential confounders. Mediation analyses were performed to estimate how much of the association between BMI and genital anomalies were mediated through obesity-related diseases.

RESULTS

Of the 1 055 705 live-born singleton boys born from 1992 to 2012, 6807 (6.4 per 1000) were diagnosed with hypospadias and 16 469 (15.6 per 1000) were diagnosed with cryptorchidism, of which 9768 (9.3 per 1000) underwent corrective surgery for cryptorchidism. We observed dose-response associations between maternal BMI and hypospadias and cryptorchidism. Boys of mothers with BMI ≥40.0 kg/m² had the highest adjusted hazard ratios for hypospadias (HR 1.35, 95% confidence interval [CI] 1.04, 1.76) and cryptorchidism (HR 1.25, 95% CI 1.00, 1.58). A substantial proportion of the associations between BMI and the genital anomalies were mediated through preeclampsia.

CONCLUSION

This large register-based study adds to the current literature and indicates that the occurrence of hypospadias and cryptorchidism increase with maternal overweight and obesity severity.

Placental pathology and hypospadias

BACKGROUND

Studies have shown that hypospadias is associated with placenta-mediated pregnancy complication (PMPC). The role of placental lesions is still unclear. We aimed to examine the association between hyposadias and placental pathology, and the effect of PMPC.

METHODS

Using data from the US Collaborative Perinatal Project in 1959-1966, we identified 15,780 male subjects (167 hypospadias) for analysis. Detailed placental examinations were conducted following a standard protocol. Subjects were divided into two groups according to whether they had PMPC, including small-for-gestational-age, pre-eclampsia/eclampsia or placental abruption. Logistic regression models were used to explore the association.

RESULTS

The prevalence of hypospadias was two times higher in subjects with PMPC than those without. Compared to pregnancies with PMPC but no hypospadias, those with both PMPC and hypospadias had significant higher prevalence of placental lesions, such as low placental weight, vascular lesions, villous lesions, and membranous insertion of cord (adjusted odds ratio (OR) ranging from 2.6 to 5.2) after adjusting for potential confounders. In subjects without PMPC, no significant difference of placental pathology was found between those with or without hypospadias.

CONCLUSION

About one third of hypospadias cases were complicated with PMPC and had a higher risk of placental lesions, suggesting heterogeneity of hypospadias etiology and mechanisms.