Cryptorchidism and hypospadias in a cohort of 934,538 Danish boys: the role of birth weight, gestational age, body dimensions, and fetal growth

The epidemiology of cryptorchidism and potential risk factors, including endocrine disrupting chemicals

Congenital cryptorchidism, also known as undescended testis, is the condition where one or both testes are not in place in the scrotum at birth and is one of the most common birth defects in boys. Temporal trends and geographic variation in the prevalence of cryptorchidism from 1% to 9% have been reported in prospective cohort studies. The testes develop in the abdominal cavity and descend to the scrotum in two phases, which should be completed by gestational week 35. Thus, the risk of cryptorchidism is higher in preterm boys. In many cases a spontaneous descent occurs during the first months of life during the surge of gonadotropins and testosterone. If not, the testis is usually brought down to the scrotum, typically by surgery, to increase future fertility chances and facilitate cancer surveillance. The increasing frequency of impaired semen quality and testicular cancer, with which cryptorchidism is associated, represents a concern for male reproductive health in general and a need to understand its risk factors. The risk of cryptorchidism is closely related to gestational factors (preterm birth, low birth weight and intrauterine growth restriction), and especially maternal smoking seems to be a risk factor. Evidence is accumulating that the increasing prevalence of cryptorchidism is also related to prenatal exposure to environmental chemicals, including endocrine disrupting compounds. This association has been corroborated in rodents and supported by ecological studies. Conducting human studies to assess the effect of endocrine disrupting chemicals and their interactions is, however, challenged by the widespread concomitant exposure of all humans to a wide range of chemicals, the combined effect of which and their interactions are highly complex.

The Androgen Metabolome of Preterm Infants Reflects Fetal Adrenal Gland Involution

CONTEXT

The human adrenal cortex changes with fetal-neonatal transition from the fetal to the adult organ, accompanied by changes in the steroid metabolome.

OBJECTIVE

As it is unclear how the observed developmental changes differ between preterm and full-term neonates, we investigated whether the involution of the fetal adrenals is following a fixed time course related to postmenstrual age or whether it is triggered by birth. Furthermore, the fetal and postnatal androgen metabolome of preterm infants was characterized in comparison to term babies.

METHODS

This was a prospective, longitudinal, 2-center study collecting spot urines of preterm and term infants during the first 12 to 18 months of life. Steroid metabolites were measured from spot urines by gas chromatography-mass spectrometry. Data relating were modeled according to established pre- and postnatal pathways.

RESULTS

Fetal adrenal involution occurs around term-equivalent age in preterm infants and is not triggered by premature birth. Testosterone levels are higher in preterm infants at birth and decline slower until term compared to full-term babies. Dihydrotestosterone levels and the activity of the classic androgen biosynthesis pathway are lower in premature infants as is 5α-reductase activity. No difference was found in the activity of the alternate backdoor pathway for androgen synthesis.

CONCLUSION

Human adrenal involution follows a strict timing that is not affected by premature birth. By contrast, prematurity is associated with an altered androgen metabolome after birth. Whether this reflects altered androgen biosynthesis in utero remains to be investigated.

Being born small for gestational age (SGA) might be associated with a higher reoperation rate in proximal hypospadias

PURPOSE

Being born small for gestational age (SGA) is associated with a higher frequency and more severe forms of hypospadias as well as with potential developmental differences. This study aims to characterize operative outcomes in SGA boys compared to boys born with normal weight and length for gestational age (appropriate/large for gestational age, AGA/LGA).

METHODS

Demographic data, hypospadias characteristics, associated pathologies and operative outcomes of boys who underwent hypospadias repair at a single center (10/2012-10/2019) were evaluated. Boys were categorized into SGA and non-SGA, which were then compared using unpaired t-tests and chi square tests. To examine the effect of SGA on reoperative risk, a logistic regression model was applied integrating surgical technique, meatal localization and complex hypospadias (narrow glans/plate, curvature, micropenis, bilateral cryptorchidism).

RESULTS

SGA boys accounted for 13.7% (n = 80) of the total cohort (n = 584) and 33% of all proximal hypospadias (n = 99, SGA vs. non-SGA 41.3% vs. 13%, p < 0.001). After a mean follow-up of 18.6 months the reoperation rate for all hypospadias was 17.9% (n = 105). In distal hypospadias there was no difference in reoperation rate between SGA and AGA/LGA boys (p = 0.548, multivariate regression model). For each meatal localization in proximal hypospadias SGA was a significant, independent factor predicting higher reoperation rates (p = 0.019, OR 3.21) in a logistic regression model (Figure ROC).

DISCUSSION

Hypospadias surgery carries a substantial risk for unplanned reinterventions. Apart from meatal localization, there are only a few factors (urethral plate quality, glandular diameter, curvature) reported in literature to be associated with reoperative risk. Intrauterine growth retardation associated with SGA might lead to not only a higher probability of proximal hypospadias but also contribute to a higher risk for complications mediated by developmental differences. Whether these findings could help to tailor surgical strategies or adjuvant measures, as for example the application of preoperative hormonal stimulation remains to be determined in future studies. This study is limited by being a single-center series with limited follow-up resulting in some complications probably not yet detected - however, in the same extent in both groups.

CONCLUSION

Based on this study, 33% of all proximal hypospadias cases occur in boys born SGA. While the reoperation rate in boys with distal hypospadias was not influenced by SGA status, SGA proved to be an independent predictor of a higher risk of reoperation in those with proximal hypospadias. After validation of these findings in other centers, this could be integrated into counseling and risk-stratification.

Maternal Cigarette Smoking During Pregnancy and Genital Anomalies in Boys: A Register-Based Cohort and Sibling-Matched Design Study

Purpose

Cryptorchidism and hypospadias share several prenatal risk factors. However, in published studies, boys exposed to cigarette smoking during pregnancy have a higher risk of cryptorchidism and a lower risk of hypospadias. Using Danish register-based data, we revisited these findings with a cohort and sibling-matched design to investigate the potential effect of shared time-stable factors.

Patients and Methods

For the cohort study, we included 823,670 live-born, singleton boys born from 1991 to 2016. Crude and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox regression models for each genital anomaly according to maternal cigarette smoking during pregnancy. For the sibling-matched design, we included 399,258 brothers and used a stratified Cox regression model creating family-adjusted results.

Results

In the cohort study, we found a higher risk of cryptorchidism (aHR = 1.18, 95% CI: 1.12, 1.24) and a lower risk of hypospadias (aHR = 0.84, 95% CI: 0.76, 0.93) when comparing boys exposed to cigarette smoking with non-exposed, and for increasing numbers of cigarettes smoked. In comparison, the sibling-matched analyses suggested a slightly weaker association for cryptorchidism and an association of similar magnitude for hypospadias, both in the same direction as in the cohort study.

Conclusion

Shared, familial confounding does not seem to explain earlier findings of higher risk of cryptorchidism and lower risk of hypospadias.

Lifestyle in Pregnancy and Hypospadias in Sons: A Study of 85,923 Mother-Son Pairs from Two Danish Pregnancy Cohorts

Purpose

Hypospadias is one of the most frequent male congenital malformations. It remains controversial whether maternal lifestyle during pregnancy may affects the risk of having a son with hypospadias, especially for smoking with many suggesting lower risk. We assessed the individual and joint associations between maternal cigarette smoking, pre-pregnancy body mass index (BMI), alcohol consumption, binge drinking, and caffeine consumption and occurrence of hypospadias in sons.

Patients and Methods

This cohort study utilized the Danish National Birth Cohort and the Aarhus Birth Cohort, holding detailed information on lifestyle factors in early pregnancy between 1989 and 2012. The Danish health registers were used to identify boys with hypospadias, according to International Classification of Diseases. Potential confounders and covariates were identified by literature search and use of directed acyclic graphs. Missing data were handled by multiple imputation and Cox proportional hazards models were applied to analyse data.

Results

In total, 85,923 live-born singleton boys were included in the study of whom 502 (0.6%) were diagnosed with hypospadias. Maternal smoking in early pregnancy was associated with lower occurrence of hypospadias. An increase of one cigarette smoked per day was associated with lower risk of having a son with hypospadias (adjusted hazard ratio (HR) 0.97 (95% confidence interval (CI) 0.94, 1.00)). However, sub-analyses suggested that the results may be prone to unadjusted confounding. We found no association between pre-pregnancy BMI, alcohol consumption, binge drinking, or caffeine consumption and hypospadias.

Conclusion

Maternal smoking during pregnancy was associated with lower occurrence of hypospadias but we cannot exclude uncontrolled confounding. The other investigated maternal lifestyle factors were not associated with hypospadias in sons.

Sonographic evaluation of fetal scrotum, testes and epididymis

External male genitalia have rarely been evaluated on fetal ultrasound. Apart from visualization of the penis for fetal sex determination, there are no specific instructions or recommendations from scientific societies. This study aimed to review the current knowledge about prenatal diagnosis of the scrotum and internal structures, with discussion regarding technical aspects and clinical management. We conducted an article search in Medline, EMBASE, Scopus, Google Scholar, and Web of Science databases for studies in English or Spanish language that discussed prenatal scrotal pathologies. We identified 72 studies that met the inclusion criteria. Relevant data were grouped into sections of embryology, ultrasound, pathology, and prenatal diagnosis. The scrotum and internal structures show a wide range of pathologies, with varying degrees of prevalence and morbidity. Most of the reported cases have described incidental findings diagnosed via striking ultrasound signs. Studies discussing normative data or management are scarce.

Androgens and the masculinization programming window: human-rodent differences

Human male reproductive disorders are common and may have a fetal origin - the testicular dysgenesis syndrome (TDS) hypothesis. In rats, experimentally induced TDS disorders result from disruption of fetal androgen production/action specifically in the masculinization programming window (MPW). MPW androgen action also programs longer anogenital distance (AGD) in male versus female rats; shorter male AGD is correlated with risk and severity of induced TDS disorders. AGD thus provides a lifelong, calibrated readout of MPW androgen exposure and predicts likelihood of reproductive dysfunction. Pregnant rat exposure to environmental chemicals, notably certain phthalates (e.g. diethyl hexl phthalate, DEHP; dibutyl phthalate, DBP), pesticides or paracetamol, can reduce fetal testis testosterone and AGD and induce TDS disorders, provided exposure includes the MPW. In humans, AGD is longer in males than females and the presumptive MPW is 8-14 weeks' gestation. Some, but not all, epidemiological studies of maternal DEHP (or pesticides) exposure reported shorter AGD in sons, but this occurred at DEHP exposure levels several thousand-fold lower than are effective in rats. In fetal human testis culture/xenografts, DEHP/DBP do not reduce testosterone production, whereas therapeutic paracetamol exposure does. In humans, androgen production in the MPW is controlled differently (human chorionic gonadotrophin-driven) than in rats (paracrine controlled), and other organs (placenta, liver, adrenals) contribute to MPW androgens, essential for normal masculinization, via the 'backdoor pathway'. Consequently, early placental dysfunction, which is affected by maternal lifestyle and diet, and maternal painkiller use, may be more important than environmental chemical exposures in the origin of TDS in humans.

Birth weight for gestational age and the risk of infertility: a Danish cohort study

STUDY QUESTION

Is birth weight for gestational age associated with infertility in adulthood among men and women?

SUMMARY ANSWER

Being born small for gestational age (SGA) was associated with infertility in adulthood among men.

WHAT IS KNOWN ALREADY

Fetal growth restriction may affect fertility, but results from previous studies have been inconsistent.

STUDY DESIGN, SIZE, DURATION

In this population-based cohort study, we used data from a Danish birth cohort, including 5594 men and 5342 women born between 1984 and 1987. Information on infertility was obtained from Danish health registers during the period from the participants' 18th birthday and up until 31 December 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were men and women born in two Danish municipalities, Aalborg and Odense. Information on birth weight and gestational age was obtained from birth records, and information on infertility diagnoses and fertility treatment was retrieved from the Danish National Patient Registry (NPR) and the Danish In Vitro Fertilisation (IVF) registry. Information on potential maternal confounders was obtained from questionnaires during pregnancy and was included in adjusted analyses. Logistic regression analysis was used to estimate crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for infertility according to birth weight for gestational age.

MAIN RESULTS AND THE ROLE OF CHANCE

Men born SGA had a 55% higher risk of being diagnosed with or treated for infertility compared to men born appropriate for gestational age (AGA) (adjusted OR = 1.55, 95% CI: 1.09-2.21). The association attenuated after exclusion of men born with hypospadias or cryptorchidism (OR = 1.37, 95% CI: 0.93-2.01). No association was found between women's birth weight for gestational age and risk of infertility (adjusted OR = 1.00, 95% CI: 0.73-1.37).

LIMITATIONS, REASONS FOR CAUTION

Estimation of gestational age is associated with some uncertainty and might have caused non-differential misclassification. The study design implicitly assumed similar distribution of reproductive and health-seeking behaviour across the groups that were compared.

WIDER IMPLICATIONS OF THE FINDINGS

Men born SGA had a higher risk of infertility. Genital malformations may account for part of the observed association, but this must be explored further.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Health, Aarhus University. No competing interests are declared.

TRIAL REGISTRATION NUMBER

N/A.

Role of Imprinting Disorders in Short Children Born SGA and Silver-Russell Syndrome Spectrum

BACKGROUND

(Epi)genetic disorders associated with small-for-gestational-age with short stature (SGA-SS) include imprinting disorders (IDs). Silver-Russell syndrome (SRS) is a representative ID in SGA-SS and has heterogenous (epi)genetic causes.

SUBJECTS AND METHODS

To clarify the contribution of IDs to SGA-SS and the molecular and phenotypic spectrum of SRS, we recruited 269 patients with SGA-SS, consisting of 103 and 166 patients referred to us for genetic testing for SGA-SS and SRS, respectively. After excluding 20 patients with structural abnormalities detected by comparative genomic hybridization analysis using catalog array, 249 patients were classified into 3 subgroups based on the Netchine-Harbison clinical scoring system (NH-CSS), SRS diagnostic criteria. We screened various IDs by methylation analysis for differentially methylated regions (DMRs) related to known IDs. We also performed clinical analysis.

RESULTS

These 249 patients with SGA-SS were classified into the "SRS-compatible group" (n = 148), the "non-SRS with normocephaly or relative macrocephaly at birth group" (non-SRS group) (n = 94), or the "non-SRS with relative microcephaly at birth group" (non-SRS with microcephaly group) (n = 7). The 44.6% of patients in the "SRS-compatible group," 21.3% of patients in the "non-SRS group," and 14.3% in the "non-SRS with microcephaly group" had various IDs. Loss of methylation of the H19/IGF2:intergenic-DMR and uniparental disomy chromosome 7, being major genetic causes of SRS, was detected in 30.4% of patients in the "SRS-compatible group" and in 13.8% of patients in the "non-SRS group."

CONCLUSION

We clarified the contribution of IDs as (epi)genetic causes of SGA-SS and the molecular and phenotypic spectrum of SRS. Various IDs constitute underlying factors for SGA-SS, including SRS.

Association of abnormal placental perfusion with the risk of male hypospadias: a hospital-based retrospective cohort study

BACKGROUND

The effect and extent of abnormal placental perfusion (APP) on the risk of male hypospadias are poorly understood. We compared the prevalence of male hypospadias in the offspring of women with APP and quantify the extent of the APP effect on the anomaly.

METHODS

A hospital-based retrospective analysis of births from 2012 to 2016 was conducted in 2018. Women of singleton pregnancy and male infants born to them were included (N = 21,447). A multivariate analysis was performed to compare the prevalence of male hypospadias in infants exposed to APP with those that were not exposed to APP.

RESULTS

Compared with the infants of women without APP, infants of women with APP showed an increased risk of male hypospadias (odds ratio, 2.40; 95% confidence interval, 1.09-5.29). The male hypospadias cumulative risk increased with the severity of APP. Infants exposed to severe APP had a significantly higher risk of male hypospadias than those without APP exposure (9.2 versus 1.7 per 1000 infants, P < 0.001). A path analysis indicated that 28.18-46.61% of the risk of hypospadias may be attributed to the effect of APP.

CONCLUSIONS

Male hypospadias risk was associated with APP and increased with APP severity, as measured in the second trimester. APP had an important role in the development of the anomaly.

Oral contraceptive use and genital anomalies in sons. A Danish cohort study

Exposure to exogenous sex hormones with estrogenic or anti-androgen properties may influence intrauterine development of male genitals. This population-based cohort study based on data from 44,408 live-born singleton sons in the Danish National Birth Cohort (DNBC) aimed to investigate whether maternal use of oral contraceptives prior to or during early pregnancy increase the risk of cryptorchidism or hypospadias. We found no consistent association between use of oral contraceptives and cryptorchidism or hypospadias, neither in those exposed any time four months prior to conception [cryptorchidism: adjusted Odds Ratio (aOR): 1.06 (95% CI: 0.91; 1.23), hypospadias: 0.74 (95% CI: 0.53; 1.03)] nor in those exposed any time during the first trimester of pregnancy [cryptorchidism: aOR: 0.93 (95% CI: 0.53; 1.62), hypospadias: 1.02 (95% CI: 0.32; 3.23)]. Despite relatively strong exposure levels from oral contraceptive use in pregnancy, this study revealed no evidence of an increased risk of either two genital malformations.

Altered umbilical sex steroids in preterm infants born small for gestational age

Background: Boys born small for gestational age (SGA) are at increased risk of testicular dysgenesis syndrome, and girls born SGA face the risk of polycystic ovary syndrome later in life. Our aim was to study whether neonates born SGA have an altered profile of steroid hormones at birth.Materials and methods: A total of 168 singletons (99 boys, 69 girls) born at 32.0-36.9 gestational weeks were recruited to a population-based, university hospital, single-center study. Of these, 31 infants (17 boys, 14 girls) were born SGA. The concentrations of dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, estrone, estradiol, cortisone, and cortisol were analyzed in umbilical cord serum with mass spectrometry.Results: Girls born SGA had higher levels of androstenedione than girls born appropriate for gestational age (AGA) (4.0 versus 2.6 nmol/L, p = .002). Boys born SGA had lower levels of estrone than boys born AGA (33 822 versus 62 471 pmol/L, p = .038). Infants born SGA had lower levels of cortisone than infants born AGA, both in girls (340 versus 579 nmol/L, p = .010) and in boys (308 versus 521 nmol/L, p = .045). Furthermore, boys born SGA had a higher cortisol/cortisone ratio than boys born AGA (0.41 versus 0.25, p = .028). Gestational age correlated with DHEAS (boys r = 0.48, p = .000, girls r = 0.35, p = .013), and cortisol (boys r = 0.48, p = .000, girls r = 0.29, p = .039).Conclusions: In moderate-to-late preterm infants born SGA, we observed a different steroid hormone profile in cord serum. Girls born SGA show increased levels of androstenedione and boys born SGA show decreased levels of estrone in cord serum, which could be related to placental aromatase deficiency in intrauterine growth restriction.

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.

Risk factors affecting post-pubertal high serum follicle-stimulating hormone in patients with hypospadias

Purpose

The factors affecting spermatogenesis in adulthood in patients with hypospadias (HS) are not clearly understood. In the present study, risk factors affecting post-pubertal high serum follicle-stimulating hormone (FSH) were evaluated in patients with HS.

Materials and methods

Among those with a history of HS surgery, patients in whom endocrinological evaluation regarding pituitary–gonadal axis was performed at 15 years of age or older between March 2004 and April 2018 were enrolled in the present study. High serum FSH was defined as greater than 10 mIU/ml. The severity of HS was divided into mild and severe. Factors affecting the post-pubertal high serum FSH were estimated.

Results

Seventy-nine patients were included in the present study. The severity of HS was mild in 35 and severe in 44. History of undescended testis (UDT) was confirmed in 12. High serum FSH was detected in nine. On logistic regression model analysis, a history of UDT was the only significant factor for high serum FSH. The incidence of high serum FSH in patients with UDT was significantly higher than that in those without UDT (58.3% vs 7.5%, p < 0.01). When stratified by severity of HS and the presence of UDT, high serum FSH was detected in 70% in patients with severe HS and UDT, whereas less than 10% in other groups.

Conclusions

A history of UDT was a significant factor for post-pubertal high serum FSH in patients with HS. Accordingly, the presence of UDT may be a marker for impaired spermatogenesis in patients with HS, especially in severe cases.

Hypertensive Disorders of Pregnancy and Genital Anomalies in Boys: A Danish Nationwide Cohort Study

BACKGROUND

Although congenital abnormalities in the male reproductive tract are common, their causes remain poorly understood. We studied associations between hypertensive disorders of pregnancy (pregestational hypertension, gestational hypertension, and preeclampsia) and the genital anomalies, cryptorchidism (undescended testes), and hypospadias (ventrally displaced urethral meatus).

METHODS

We established a population of 1,073,026 Danish boys born alive between 1 January 1978 and 31 December 2012. By means of Cox regression analyses, we estimated hazard ratios with 95% confidence intervals for cryptorchidism and hypospadias according to type and severity of hypertensive disorder. Further, we used restricted cubic spline analyses to investigate the association between gestational age at onset of severe and moderate preeclampsia and the two genital anomalies.

RESULTS

We found associations between pregestational hypertension and cryptorchidism (HR: 1.3; 95% CI = 1.1, 1.6) and hypospadias (HR: 1.7; 95% CI = 1.3, 2.3), whereas gestational hypertension was only associated with cryptorchidism (HR: 1.2; 95% CI = 1.1, 1.4). Boys of mothers with preeclampsia had the highest occurrence of cryptorchidism and hypospadias, increasing with preeclampsia severity. Women with HELLP syndrome faced the highest risk of having a child with both cryptorchidism (HR: 2.1; 95% CI = 1.4, 3.2) and hypospadias (HR: 3.9; 95% CI = 2.5, 6.1). Further, the occurrence increased with early onset of preeclampsia diagnosis.

CONCLUSIONS

These findings support the hypotheses that preeclampsia and genital anomalies share common etiologic factors and that placental dysfunction and androgen deficiency in early pregnancy are important in the etiology of male genital anomalies.

Family and neighborhood socioeconomic inequality in cryptorchidism and hypospadias: A nationwide study from Sweden

OBJECTIVES

To examine whether there is an association between neighborhood deprivation and incidence of cryptorchidism and hypospadias, after accounting for family-level and individual-level sociodemographic characteristics.

METHODS

All boys born in Sweden between January 1, 2001 and December 31, 2010 were followed. Data were analyzed by multilevel logistic regression, with family-level and individual-level characteristics at the first level and level of neighborhood deprivation at the second level.

RESULTS

During the study period, among a total of 497,584 boys, 8,584 (1.7%) and 3,704 (0.7%) were diagnosed with cryptorchidism and hypospadias, respectively. Cumulative rates for cryptorchidism and hypospadias increased with increasing levels of neighborhood deprivation. In the study population, 1.5 per 100 and 2.0 per 100 boys, in the least and most deprived neighborhoods were diagnosed with cryptorchidism and 0.7 per 100 and 0.9 per 100 boys were diagnosed with hypospadias. Incidence of hospitalization for cryptorchidism and hypospadias increased with increasing neighborhood-level deprivation across all family-level and individual-level sociodemographic categories. The odds ratio (OR) for cryptorchidism and hypospadias for those living in high-deprivation neighborhoods versus those living in low-deprivation neighborhoods was 1.13 (95% confidence interval [CI] = 1.05-1.21) and 1.24 (95% CI = 1.12-1.37). High neighborhood deprivation remained significantly associated with higher odds of hypospadias after adjustment for family-level and individual-level sociodemographic characteristics (OR = 1.20, 95% CI = 1.08-1.35).

CONCLUSIONS

This study is the largest so far on neighborhood influences on cryptorchidism and hypospadias. Our results suggest that neighborhood deprivation is associated with a moderate incidence of hypospadias independent of family-level and individual-level sociodemographic characteristics.

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.

In-utero Exposure to Maternal Stressful Life Events and Risk of Cryptorchidism: The Raine Study

Cryptorchidism, registered at birth or later, is the most common birth defect in males in western countries, estimated to affect around 2-3% of newborn boys, declining to around 2% at 3 months. We have previously described a potential association between stressful life events (SLEs) in pregnancy and reduced semen quality and testosterone levels in adult offspring. Both outcomes are believed to share a common etiology with cryptorchidism thus increased risk of cryptorchidism in boys exposed to prenatal SLEs may be plausible. The risk of cryptorchidism associated with prenatal SLE amongst 1,273 male Generation 2 offspring was estimated using the Western Australian Pregnancy (Raine) Study. SLEs are discrete experiences that disrupt an individual's usual activities causing a life change and readjustment, such as death of a relative or friend, divorce, illness or job loss. Mothers prospectively reported SLEs, during pregnancy at gestational weeks (GW) 18 and 34 using a standardized 10-point questionnaire. A boy was diagnosed as cryptorchid if one or both testes was non-palpable in the scrotum and not able to be manipulated into the scrotum. Twenty-four (2%) cryptorchid boys were identified. Mean (standard deviation) of SLE exposures in GW34 was 1.1 (1.2) for non-cryptorchid boys and slightly higher 1.5 (1.8) for cryptorchid boys, similar differences were observed in GW18. Adjusted odds ratio [OR] and 95% confidence intervals (CI) for risk of cryptorchidism in early (18-weeks) and late gestation (34-weeks) according to prenatal SLE exposures were: 1.06 (95% CI: 0.77-1.45) and 1.18 (95% CI: 0.84-1.67), respectively. This is the first-time report on the possible relationships between exposure to early and late pregnancy SLEs and risk of cryptorchidism in a birth cohort. Prenatal SLE exposure was not associated with a statistically significant increase in the risk of cryptorchidism in male offspring. A small case population limits the statistical power of the study and future larger studies are required to evaluate this potential association.

Molecular genetics of hypospadias and cryptorchidism recent developments

During the last decade, a tremendous amount of work has been devoted to the study of the molecular genetics of isolated hypospadias and cryptorchidism, two minor forms of disorders of sex development (DSD). Beyond the genes involved in gonadal determination and sex differentiation, including those underlying androgen biosynthesis and signaling, new genes have been identified through genome-wide association study and familial clustering. Even if no single genetic defect can explain the whole spectrum of DSD, these recent studies reinforce the strong role of the genetic background in the occurrence of these defects. The timing of signaling disruption may explain the different phenotypes.

Birth prevalence of hypospadias and hypospadias risk factors in newborn males in the United States from 1997 to 2012

BACKGROUND

Hypospadias is a common genitourinary malformation and there are conflicting data on whether its prevalence is increasing. Previous studies have described associations with risk factors including small for gestational age (SGA), multiple gestation birth, environmental influences, and maternal factors.

OBJECTIVE

The objective of this study was to examine birth prevalence of hypospadias and hypospadias risk factors in a large national dataset and to evaluate for changes from 1997 to 2012. We hypothesized that any increase in the birth prevalence of hypospadias would be associated with an increase in risk factors such as SGA, prematurity, or multiple gestation birth.

STUDY DESIGN

The Kids' Inpatient Database was used to generate national estimates for prevalence of males born with hypospadias, SGA, prematurity, or to a multiple gestation and then prevalences were evaluated for association with time. Multivariable logistic regression was used to evaluate whether birth prevalence of hypospadias was associated with increasing year, SGA, prematurity, and multiple gestation birth.

RESULTS

The estimated birth prevalence of hypospadias increased from 6.1 per 1000 births (95% confidence interval [CI] 5.9 to 6.3) to 6.8 per 1000 births (95% CI 6.7 to 7.0), an 11.5% increase from 1997-2012 (P = 0.014). Among male births, the prevalence of SGA increased 74%, multiple gestation increased 25%, and prematurity increased 20% (P < 0.001 for all) (Summary Figure). A risk factor was seen in around 20% of males born with hypospadias. Hypospadias birth prevalence also increased in males without risk factors but was not statistically significant (9.1% increase, P = 0.5). On multivariable logistic regression, being born SGA (odds ratio [OR] = 3.3), to a multiple gestation (OR = 1.1), or premature (OR 1.9) were associated with increased odds of hypospadias (P < 0.01 for all), whereas increasing year was not (P = 0.3).

CONCLUSIONS

The estimated birth prevalence of hypospadias in the United States increased from 6.1 to 6.8 per 1000 births from 1997 to 2012. Known hypospadias risk factors of SGA birth, multiple gestation birth, and premature birth also increased over this time to a higher degree. About 20% of males born with hypospadias had one of these risk factors. The birth prevalence of hypospadias in males without any studied risk factors also increased, but this was not statistically significant. More studies are needed to evaluate whether this increase in hypospadias prevalence is due to increases in known hypospadias risk factors, new environmental exposures, improved diagnosis at birth, some combination, or unrelated causes.

Acquired undescended testis and possibly associated testicular torsion in children with cerebral palsy or neuromuscular disease

INTRODUCTION

Torsion of an undescended testis (UDT) associated with cerebral palsy (CP) and neuromuscular disease (NMD) is an uncommon condition that is not well recognized by primary care physicians or healthcare providers.

OBJECTIVE

The objective of this study was to highlight the clinical importance of torsion of a UDT in children with CP and NMD.

MATERIALS AND METHODS

Eleven children with testicular torsion of a UDT operated on at the study institute between 1991 and 2015 were identified. The records of seven children (63.6%) associated with CP or NMD were retrospectively reviewed. Clinical findings of testicular torsion were assessed along with the treatment outcome and testicular salvageability.

RESULTS

All seven children were not identified with a UDT by public health checkup for infant and young children. No children with CP or NMD had torsion of a descended testis during the present study period. Median age at surgery was 15 years (range, 1-20 years). The testis location was at the external inguinal ring in five patients, in the inguinal canal in one, and in the superficial inguinal pouch in one. Of the contralateral testes, four were a UDT, one was a retractile testis, and two were descended testes. Orchiectomy was performed in six patients (85.7%). In the remaining patients, the testis was preserved but became atrophic.

DISCUSSION

This study demonstrated that children with CP or NMD may be affected with torsion of a UDT with peak at around puberty with the poor salvage rate, even if the testes appear descended in infancy and young children. Shortcomings of this study were the retrospective design and a small series of children undergoing surgery for torsion of a UDT.

CONCLUSION

Pediatric urologists need to educate primary care physicians and healthcare providers in the recognition of acquired UDTs and possibly associated testicular torsion in children with CP and NMD. Genital examination should be continued regularly until adolescence in these children to detect acquired UDT. These children should be referred to pediatric urologists to promote surgery as soon as the diagnosis of acquired UDT is carried out. It is believed that it is perhaps the best approach to prevent loss of the testis in children with CP and NMD.

Lifestyle in pregnancy and cryptorchidism in sons: a study within two large Danish birth cohorts

Purpose

Cryptorchidism is the most frequent congenital malformation in boys and is associated with low sperm count, infertility and testicular cancer. Unhealthy maternal lifestyle during pregnancy such as smoking, high prepregnancy body mass index (BMI) as well as alcohol and caffeine intake may constitute possible risk factors for cryptorchidism, but results from the few previous studies are conflicting. We aimed to explore the association between maternal lifestyle factors and occurrence of cryptorchidism in sons.

Patients and methods

The Danish National Birth Cohort and the Aarhus Birth Cohort provided information on maternal lifestyle from early pregnancy. Data were linked to several Danish health registers, multiple imputation was used to handle missing data and Cox proportional hazards models were used to adjust for potential confounders.

Results

In total, 85,923 boys were included, and of them, 2.2% were diagnosed with cryptorchidism. We observed the strongest associations between maternal tobacco smoking and prepregnancy BMI and cryptorchidism. Sons of women who smoked 10–14 cigarettes/day had the highest hazard ratio (HR) for cryptorchidism (1.37; 95% CI: 1.06–1.76), and for maternal BMI ≥30 kg/m², the HR was 1.32 (95% CI: 1.06–1.65). Binge drinking was associated with an HR <1, if the women had one or two episodes in pregnancy (HR: 0.81; 95% CI: 0.67–0.98). Average maternal alcohol intake and caffeine intake during pregnancy were not significantly associated with a higher occurrence of cryptorchidism detected at birth or later in life.

Conclusion

Maternal tobacco smoking, overweight and obesity in pregnancy were associated with higher occurrence of cryptorchidism in boys in this study.

"The next-generation": Long-term reproductive outcome of adults born at a very low birth weight

BACKGROUND

Preterm birth at very low birth weight (VLBW, <1500g) has a multitude of consequences that extend to various aspects of adult life. Little is known about the long-term reproductive outcome of VLBW that survive to adulthood.

AIMS

To evaluate the reproductive outcome of VLBW infants who survive to adulthood (next-generation).

STUDY DESIGN

Retrospective cohort.

SUBJECTS

Infants born at a single tertiary center between the years 1982-1997 who survived to 18years of age (first-generation).

OUTCOME MEASURES

The number and the birth weight of offspring from adults born with VLBW were compared to those of other birth weight groups born in the same epoch: 1500-2499g, 2500-3799g (reference group) and ≥3800g. We calculated the ratio of actual compared to expected number of children in the next-generation for extreme birth weight parents, using the reference group as a control group and adjusting for birth year. Thereafter, we measured whether first-generation VLBW had an increased risk for a VLBW in the next-generation.

RESULTS

After exclusions, we identified first-generation 67,183 births, including 618 (9.2%) VLBW. There were 193 males and 184 female VLBW infants who survived to adulthood. Both female and male first-generation patients from the VLBW group had half the reproductive rate relative for the normal birth weight group. After adjusting for parental age, male and female VLBW survivors had no significant risk for a VLBW neonate in the next-generation, however, the overall number of are small and may limit any conclusion.

CONCLUSION

VLBW children who reach adulthood may be at a significantly lower reproductive capacity.

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.

Risk factors for cryptorchidism

Undescended testis - known as cryptorchidism - is one of the most common congenital abnormalities observed in boys, and is one of the few known risk factors for testicular cancer. The key factors that contribute to the occurrence of cryptorchidism remain elusive. Testicular descent is thought to occur during two hormonally-controlled phases in fetal development - between 8-15 weeks (the first phase of decent) and 25-35 weeks gestation (the second phase of descent); the failure of a testis to descend permanently is probably caused by disruptions to one or both of these phases, but the causes and mechanisms of such disruptions are still unclear. A broad range of putative risk factors have been evaluated in relation to the development of cryptorchidism but their plausibility is still in question. Consistent evidence of an association with cryptorchidism exists for only a few factors, and in those cases in which evidence seems unequivocal the factor is likely to be a surrogate for the true causal exposure. The relative importance of each risk factor could vary considerably between mother-son pairs depending on an array of genetic, maternal, placental and fetal factors - all of which could vary between regions. Thus, the role of causative factors in aetiology of cryptorchidism requires further research.

Single penile incision for combined hypospadias and inguinal surgery: A comparative study

INTRODUCTION

We sought to compare the surgical outcomes of hypospadias repair with correction of inguinal pathology using a single penile incision vs. conventional approach using two incisions.

METHODS

This is a retrospective study that reviewed all patients who underwent concurrent surgical repair for both hypospadias and inguinal pathologies between January 2003 and November 2015. Patients were classified into Group A, conventional (inguinal or scrotal and penile incision) approach; or Group B, single penile incision approach. Baseline characteristics, including age, degree of hypospadias, type and laterality of inguinal pathology, operative time, and surgical outcomes, were collected. Between groups, variable comparisons were analyzed using Mann-Whitney U-Test and Fisher-exact test. Statistical significant set at <0.05.

RESULTS

Seventy-six patients (Group A: 40; Group B: 36) were eligible for study. Baseline characteristics of both groups were comparable, with no significant statistical difference. Overall mean operative time for Group A was 139.3 ± 56.2 minutes, while Group B was 107.8 ± 46.7 minutes (Z=2.6; U=470.5; p=0.009). Two patients in Group A and two patients in Group B had testicular ascension, all of which also had hypospadias-related complications (p=1.0). Hypospadias-related complications in Group A included seven urethrocutaneous fistulae and two repair dehiscence. Eight urethrocutaneous fistulae, one urethral stricture, and two repair dehiscence occurred in Group B (p=0.448). Surgical outcome appearance in both groups were comparable, with no statistically significant difference (p=0.466).

CONCLUSIONS

Single penile incision for both hypospadias repair and correction of inguinal pathology is a feasible technique and comparable to the conventional approach, with similar surgical outcomes and shorter overall operative time.

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.

Does maternal exposure during pregnancy to higher ambient temperature increase the risk of hypospadias?

INTRODUCTION

The association between ambient temperature that the mother is exposed to during pregnancy and hypospadias has not been investigated by the studies, although the recent studies showed the correlation between some congenital malformations (congenital heart disease, neural tube defect, etc.) and ambient temperature.

OBJECTIVE

The aim was to investigate the relation between hypospadias and the ambient temperatures that the mother is exposed to during her pregnancy.

METHODS

The data of patients with hypospadias that had their gestational periods in Ankara and Istanbul regions, and had other urological treatments (circumcision, urinary tract infection, pyeloplasty, nephrolithotomy, etc.) between January 2000 and November 2015 were analyzed retrospectively. The ambient temperature at 8-14 weeks of gestation was investigated for each patient by reviewing the data of the General Directorate of Meteorology, since this period was risky for development of hypospadias. The data including ambient temperature that the pregnant mother was exposed to, maternal age, parity, economical status, gestational age at birth, and birth weight were compared between two groups. The retrospective nature of the study may be a potential source for selection bias.

RESULTS

The data of 1,709 children that had hypospadias repair and 4,946 children that had other urological treatments between 2000 and 2015 were retrospectively analyzed. There were no differences between the groups for maternal age, parity, economical status, gestational age at birth, and birth weight (Table). Analysis of exposed maximum and average ambient temperatures at 8-14 weeks of gestation revealed that July and August, hot periods in summer time, were more prevalent in the hypospadias group (p = 0.01). The average and maximum monthly ambient temperatures during summer increased the risk for hypospadias (OR, 1.32; 95% CI, 1.08-1.52; and OR, 1.22; 95% CI, 0.99-1.54, respectively.

CONCLUSIONS

In this paper, we evaluated the relation between hypospadias and the ambient temperatures that the mother is exposed during her pregnancy. The results of this study indicated that the high ambient temperatures the mother and fetus are exposed to at 8-14 weeks of gestation increased the risk of hypospadias in the offspring.

Multivariate Analysis of the Factors Associated With Sexual Intercourse, Marriage, and Paternity of Hypospadias Patients

INTRODUCTION

Patients with hypospadias are treated surgically during childhood, which has the intention of enabling a satisfactory sexual life in adulthood. However, it is unclear whether patients with corrected hypospadias can lead a satisfactory sexual life and sustain a marital relationship and produce offspring.

AIM

To evaluate factors associated with achievement of sexual intercourse, marriage, and paternity in patients with hypospadias who have reached adulthood.

METHODS

Self-completion questionnaires were mailed in April 2012 to patients with hypospadias at least 18 years old who had been treated at our institution during childhood from 1973 through 1998 by a single surgeon and the same surgical policy. Assessments included the International Prostate Symptom Score, the International Index for Erectile Function-5, and non-validated questions related to current social and physical status and sexual, marital, and paternity experiences. Candidate factors were extracted from patients' neonatal data, surgical findings and results, and current physical and social status obtained by the questionnaires.

MAIN OUTCOME MEASURES

Candidate factors associated with heterosexual intercourse, marriage, and paternity experiences were analyzed using univariate and multivariate proportional hazard models and log-rank test of Kaplan-Meier curves.

RESULTS

Of the 518 patients contacted, 108 (age = 18-50 years, median = 28 years) met the inclusion criteria. Two- and one-stage repairs were performed as the initial treatment in 79 and 12, respectively, and 17 of the analyzed cases were reoperations for patients initially treated elsewhere. Fifty-seven patients had the milder type (31 glandular, 26 penile), 36 had the proximal type (13 penoscrotal, 23 scrotal-perineal), and 15 had an unknown type. Multivariate analyses by Cox proportional hazard model and log-rank tests confirmed that experience of sexual intercourse was associated with the milder type of hypospadias (P = .025 and .0076 respectively), marriage was associated with stable employment (P = .020 and .026, respectively), and paternity was associated with the absence of additional surgery after completion of the initial repair (P = .013 by multivariate analysis).

CONCLUSION

There was scant overlap of factors associated with the three events. The present findings provide reference information for surgeons and parents regarding future sexual and marriage experiences of children treated for hypospadias.

Anogenital distance as a marker of androgen exposure in humans

Abnormal foetal testis development has been proposed to underlie common disorders of the male reproductive system such as cryptorchidism, hypospadias, reduced semen quality and testicular germ cell tumour, which are regarded as components of a 'testicular dysgenesis syndrome'. The increasing trends and geographical variation in their incidence have been suggested to result from in utero exposure to environmental chemicals acting as endocrine disruptors. In rodents, the anogenital distance (AGD), measured from the anus to the base of genital tubercle, is a sensitive biomarker of androgen exposure during a critical embryonic window of testis development. In humans, several epidemiological studies have shown alterations in AGD associated with prenatal exposure to several chemicals with potential endocrine disrupting activity. However, the link between AGD and androgen exposure in humans is not well-defined. This review focuses on the current evidence for such a relationship. As in rodents, a clear gender difference is detected during foetal development of the AGD in humans which is maintained thereafter. Reduced AGD in association with clinically relevant outcomes of potential environmental exposures, such as cryptorchidism or hypospadias, is in keeping with AGD as a marker of foetal testicular function. Furthermore, AGD may reflect variations in prenatal androgen exposure in healthy children as shorter AGD at birth is associated with reduced masculine play behaviour in preschool boys. Several studies provide evidence linking shorter AGD with lower fertility, semen quality and testosterone levels in selected groups of adults attending andrology clinics. Overall, the observational data in humans are consistent with experimental studies in animals and support the use of AGD as a biomarker of foetal androgen exposure. Future studies evaluating AGD in relation to reproductive hormones in both infants and adults, and to gene polymorphisms, will help to further delineate the effect of prenatal and postnatal androgen exposures on AGD.

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

The most consistently reported risk indicators for the male genital anomalies cryptorchidism and hypospadias are prematurity and low birth weight. Placental dysfunction has been hypothesized as a possible underlying cause, and an association between placental weight at birth and hypospadias has been indicated. In a population-based cohort of 388,422 Danish singleton boys born alive (1997-2008), we studied the association between placental weight and cryptorchidism and hypospadias. Missing data were handled with multiple imputation, and we estimated hazard ratios by means of Cox regression models. During follow-up, 1,713 boys were diagnosed with hypospadias and 6,878 with cryptorchidism (3,624 underwent corrective surgery). We observed an association between low placental weight and risk of both genital anomalies. Boys with a placental weight in the lowest decile (<10%) had higher risks of both cryptorchidism (hazard ratio = 1.52, 95% confidence interval: 1.31, 1.76) and hypospadias (hazard ratio = 1.97, 95% confidence interval: 1.59, 2.45) than boys in the reference decile (50.0-59.9%). In conclusion, we found higher risks of both genital malformations in boys born with a low placental weight. The relationship seemed stronger for hypospadias than for cryptorchidism. Taken together, our data support a role for placental dysfunction in the etiology of these anomalies.

Congenital anomalies in cerebral palsy: where to from here?

Proportions of cases of cerebral palsy (CP) with congenital anomalies recorded in Australian CP registers range from 15% to 40%. The anomalies seen in CP are extremely variable. We have identified that CP registers often do not have quality data on congenital anomalies, necessitating linkage with congenital anomaly registers. However, a lack of unified processes and definitions in congenital anomaly registers and data collections means that linkages are complex, need to be carefully planned, and limitations acknowledged. Historically in CP research, congenital anomalies have been classified by International Classification of Disease codes, then combined into brain and other major and minor anomalies. Systems have been developed to classify congenital anomalies into aetiologically related groups, but such a classification has yet to be trialled in CP. It is anticipated that primary prevention of a small proportion of cases of CP is possible through the primary prevention of congenital anomalies, especially those due to teratogens. Owing to the anticipated low prevalence of each subgroup, global collaboration will be required to further these lines of enquiry.

Ethnic patterns of hypospadias in New Zealand do not resemble those observed for cryptorchidism and testicular cancer: evidence of differential aetiology?

It has been proposed that hypospadias, cryptorchidism, poor semen quality and testicular cancer might share common prenatal causes. We have previously demonstrated similar ethnic patterns for the incidence of testicular cancer and cryptorchidism - a known risk factor for testicular cancer. If the underlying exposure(s) that cause hypospadias, cryptorchidism and testicular cancer are shared, then we would expect the incidence relationship between ethnic groups to follow the same pattern across all three conditions. We followed a birth cohort of 318 345 eligible male neonates born in New Zealand between 2000-2010, and linked routinely collected maternity records with inpatient hospitalization and mortality records through to 2011. We searched hospitalization records for diagnoses of hypospadias, and used mortality records for censoring. We used Poisson regression methods to compare the relative risk of hypospadias between ethnic groups, adjusting for perinatal risk factors and total person time. We observed that European/Other children had the highest risk of hypospadias, with Māori, Pacific and Asian boys having around 40% lower risk of disease compared with this group (adjusted relative risk [RR]: Māori 0.62, 95% CI 0.55-0.70; Pacific 0.62, 95% CI 0.53-0.72; Asian 0.57, 95% CI 0.47-0.69). This contrasts substantially with our previous observations for cryptorchidism and testicular cancer, where Māori males have the greatest risk. Our observations suggest that - at least in New Zealand - the exposures that drive the development of hypospadias may differ to those that that drive the development of cryptorchidism and/or testicular cancer.

Higher Incidence of Hypospadias in Monochorionic Twins

Background:Hypospadias is associated with twinning. The incidence of hypospadias in monochorionic and dichorionic male twins is, however, yet to be determined.Methods:All medical records of monochorionic and dichorionic twins admitted to our neonatal nursery between January 2004 and August 2013 were reviewed for the presence of hypospadias.Results:A total of 350 monochorionic and 303 dichorionic male twins were included in the study. The incidence of hypospadias in monochorionic and dichorionic groups was 4% (14/350) and 1% (3/303) (p= .016) respectively. In 11 of the 15 twin couples, hypospadias occurred in the twin with the lowest birth weight. The rate of hypospadias in twin infants small-for-gestational-age group was 10% (6/60) compared with 2% (11/593) in the appropriate-for-gestational-age group (p= .002). In a multivariate analysis, both monochorionicity and small-for-gestational-age were independently associated with hypospadias, odds ratio 4.1 (95% confidence interval (CI): 1.1–14.7) and 6.1 (95% CI: 2.2–17.2) respectively.Conclusions: The incidence of hypospadias is four-fold higher in monochorionic twins compared with dichorionic twins. Hypospadias is also independently associated with small-for-gestational-age.

Approach to the Infant with a Suspected Disorder of Sex Development

A newborn with genital ambiguity requires careful diagnostic evaluation to identify the underlying etiology in an efficient manner and assign gender without lengthy delay. The infant's family needs comprehensive psychosocial support. Such infants should be referred to a multidisciplinary team with expertise in disorders of sex development.

Maternal bereavement and cryptorchidism in offspring

BACKGROUND

Cryptorchidism (undescended testis) is a common anomaly with largely unexplained etiology. Animal studies have suggested maternal emotional stress as a potential risk factor, but this has not been studied in humans. We aimed to investigate whether maternal bereavement due to the death of a close relative in the antenatal period increases the occurrence of cryptorchidism in the offspring.

METHODS

In a population-based cohort, we studied death of a close relative as the exposure and cryptorchidism entries in nationwide medical registries as the outcome. Danish national registries included 898,961 (23,609 exposed) boys born from 1978 to 2008 with a maximum of 30 years of follow-up.

RESULTS

A total of 20,947 boys had cryptorchidism, of whom 13,524 also underwent corrective surgery. We found no increased occurrence of cryptorchidism in the offspring (hazard ratio = 1.02 [95% confidence interval = 0.92-1.14]). Results were similar when the diagnosis was verified with surgery. We adjusted for maternal and paternal age, birth year, and family history of cryptorchidism.

CONCLUSION

We observed no association between maternal bereavement before and during pregnancy and the occurrence of cryptorchidism in the offspring.

Hypospadias and increased risk for neurodevelopmental disorders

BACKGROUND

Hypospadias (aberrant opening of the urethra on the underside of the penis) occurs in 1 per 300 newborn boys. It has been previously unknown whether this common malformation is associated with increased psychiatric morbidity later in life. Studies of individuals with hypospadias also provide an opportunity to examine whether difference in androgen signaling is related to neurodevelopmental disorders. To elucidate the mechanisms behind a possible association, we also studied psychiatric outcomes among brothers of the hypospadias patients.

METHODS

Registry study within a national cohort of all 9,262 males with hypospadias and their 4,936 healthy brothers born in Sweden between 1973 and 2009. Patients with hypospadias and their brothers were matched with controls by year of birth and county. The following outcomes were evaluated (1) any psychiatric (2) psychotic, (3) mood, (4) anxiety, (5) eating, and (6) personality disorders, (7) substance misuse, (8) attention-deficit hyperactivity disorder (ADHD), (9) autism spectrum disorders (ASD), (10) intellectual disability, and (11) other behavioral/emotional disorders with onset in childhood.

RESULTS

Patients with hypospadias were more likely to be diagnosed with intellectual disability (OR 3.2; 95% CI 2.8-3.8), ASD (1.4; 1.2-1.7), ADHD (1.5; 1.3-1.9), and behavioral/emotional disorders (1.4; 1.2-1.6) compared with the controls. Brothers of patients with hypospadias had an increased risk of ASD (1.6; 1.3-2.1) and other behavioral/emotional disorders with onset in childhood (1.2; 0.9-1.5) in comparison to siblings of healthy individuals. A slightly higher, although not statistically significant, risk was found for intellectual disability (1.3; 1.0-1.9). No relation between other psychiatric diagnosis and hypospadias was found.

CONCLUSIONS

This is the first study to identify an increased risk for neurodevelopmental disorders in patients with hypospadias, as well as an increased risk for ASD in their brothers, suggesting a common familial (genetic and/or environmental) liability.

Hypospadias: Prevalence, birthweight and associated major congenital anomalies

The aim of this study was to determine the prevalence of hypospadias over 24 years in a Danish population and to describe the relation to birthweight and associated major congenital anomalies. It is a population-based study of all cases (live births, fetal deaths and elective terminations of pregnancy) with hypospadias born in the period 1986-2009 in Funen County and reported to the EUROCAT registry of congenital anomalies. Cases were included only if surgery for hypospadias was performed. 223 cases of hypospadias were registered during the period 1986-2009 with an overall prevalence of 16.9 per 10 000 births. The prevalence was significantly higher in 2000-2009 compared to 1986-1999 (P < 0.001). We found a three times higher occurrence of VLBW (very low birthweight) infants among cases with hypospadias. Infants with isolated hypospadias were more likely to have mild hypospadias (68%) while cases with associated major congenital anomalies were less likely to have mild hypospadias (42%) (P < 0.05). Hypospadias was associated with VLBW and the severity of the defect was related to the presence of major congenital anomalies. The prevalence of hypospadias has increased during the study period. The relation to VLBW could indicate a causal relationship for hypospadias or a shared pathogenic factor.

Risk factors, prevalence trend, and clustering of hypospadias cases in Puerto Rico

OBJECTIVE

The aim was to determine the distribution pattern of hypospadias cases across a well-defined geographic space.

MATERIALS AND METHODS

The dataset for this study was produced by the Birth Defects Prevention and Surveillance System of the Department of Health of Puerto Rico (BDSS-PR), which linked the information of male newborns of the Puerto Rico Birth Cohort dataset (PRBC; n=92,285) from 2007 to 2010. A population-based case-control study was conducted to determine prevalence trend and to estimate the potential effects of maternal age, paternal age, birth-related variables, and health insurance status on hypospadias. Two types of geographic information systems (GIS) methods (Anselin Local Moran's I and Getis-Ord G) were used to determine the spatial distribution of hypospadias prevalence.

RESULTS

Birthweight (<2500 g), age of mother (40+years), and private health insurance were associated with hypospadias as confirmed with univariate and multivariate analyses at 95% CI. A cluster of hypospadias cases was detected in the north-central region of Puerto Rico with both GIS methods (p≤0.05).

CONCLUSIONS

The clustering of hypospadias prevalence provides an opportunity to assess the underlying causes of the condition and their relationships with geographical space.

DSDs: genetics, underlying pathologies and psychosexual differentiation

Mammalian sex determination is the unique process whereby a single organ, the bipotential gonad, undergoes a developmental switch that promotes its differentiation into either a testis or an ovary. Disruptions of this complex genetic process during human development can manifest as disorders of sex development (DSDs). Sex development can be divided into two distinct processes: sex determination, in which the bipotential gonads form either testes or ovaries, and sex differentiation, in which the fully formed testes or ovaries secrete local and hormonal factors to drive differentiation of internal and external genitals, as well as extragonadal tissues such as the brain. DSDs can arise from a number of genetic lesions, which manifest as a spectrum of gonadal (gonadal dysgenesis to ovotestis) and genital (mild hypospadias or clitoromegaly to ambiguous genitalia) phenotypes. The physical attributes and medical implications associated with DSDs confront families of affected newborns with decisions, such as gender of rearing or genital surgery, and additional concerns, such as uncertainty over the child's psychosexual development and personal wishes later in life. In this Review, we discuss the underlying genetics of human sex determination and focus on emerging data, genetic classification of DSDs and other considerations that surround gender development and identity in individuals with DSDs.

Epidemiologic methods for investigating male fecundity

Fertility is a couple concept that has been measured since the beginning of demography, and male fecundity (his biological capacity to reproduce) is a component of the fertility rate. Unfortunately, we have no way of measuring the male component directly, although several indirect markers can be used. Population registers can be used to monitor the proportion of childless couples, couples who receive donor semen, trends in dizygotic twinning, and infertility diagnoses. Studies using time-to-pregnancy (TTP) may identify couple subfecundity, and TTP data will correlate with sperm quality and quantity as well as sexual activity and a number of other conditions. Having exposure data available for couples with a fecund female partner would make TTP studies of interest in identifying exposures that may affect male fecundity. Biological indicators such as sperm quality and quantity isolate the male component of fertility, and semen data therefore remain an important source of information for research. Unfortunately, often over half of those invited to provide a sperm sample will refuse, and the study is then subject to a selection that may introduce bias. Because the most important time windows for exposures that impair semen production could be early fetal life, puberty, and the time of ejaculation; longitudinal data over decades of time are required. The ongoing monitoring of semen quality and quantity should continue, and surveys monitoring fertility and waiting TTP should also be designed.

Do ethnic patterns in cryptorchidism reflect those found in testicular cancer?

PURPOSE

There are established variations in testicular cancer incidence between ethnic groups within countries. It is currently unclear whether the occurrence of cryptorchidism-a known risk factor for testicular cancer-follows similar patterns. In New Zealand Māori have unusually high rates of testicular cancer compared to individuals of European ancestry. We hypothesized that ethnic trends in the incidence of cryptorchidism would reflect those for testicular cancer in this setting.

MATERIALS AND METHODS

We followed 318,441 eligible male neonates born in New Zealand between 2000 and 2010 for the incidence of orchiopexy confirmed cryptorchidism and the incidence of known risk factors for cryptorchidism (low birth weight, short gestation, small size for gestational age) using routine maternity, hospitalization and mortality records. Logistic regression was used to calculate odds ratios for the presence of known risk factors for cryptorchidism by ethnic group. Poisson regression was used to calculate relative risk of cryptorchidism by ethnicity, adjusted for risk factors.

RESULTS

Ethnic patterns of cryptorchidism incidence in New Zealand closely mirrored those previously observed for testicular cancer. Māori had higher rates of cryptorchidism than all other ethnic groups (adjusted RR 1.2 [95% CI 1.11-1.3]), with Pacific (0.89 [0.8-0.99]) and Asian groups (0.68 [0.59-0.79]) having the lowest rates (European/other, referent).

CONCLUSIONS

Since the principal risk factors for cryptorchidism are present in utero, the results of the current study strengthen the likelihood that the ethnic patterning of testicular cancer is at least partly due to prenatal risk factors.

The exposome--exciting opportunities for discoveries in reproductive and perinatal epidemiology

Understanding the mechanisms that underlie successful human reproduction and development is an ambitious goal, given the many unique methodological challenges surrounding such study. These challenges are well understood by reproductive and perinatal epidemiologists and include its conditional nature, unobservable yet informative outcomes such as conception, multi-scale missing data, correlated or non-independent outcomes, interval censoring and a hierarchical data structure. Novel methodologies for overcoming these challenges and for answering critical data gaps are needed if we are to better understand the inefficiency that currently characterises human reproduction with the goal of improving population health. The exposome is an emerging paradigm that offers promise for understanding the natural history of human reproduction and development, and its many associated impairments that develop later in child- or adulthood. This novel paradigm recognises the need to identify and measure the totality of environmental (non-genetic) exposures from preconception through sensitive windows, and to identify patterns associated with healthy and adverse outcomes. The exposome accommodates research focusing on unique subpopulations, such as couples undergoing assisted reproductive technologies, so that methodological limitations such as unobservable and conditional outcomes can be better addressed. Reproductive and perinatal epidemiology is uniquely suited for proof-of-concept exposome research, given the intricate relations between fecundity, gravid health and later onset disease and the narrow and interrelated sensitive windows that characterise the conditional nature of human reproduction and development. Bold new conceptual frameworks such as the exposome are needed for designing research that may lead to discovery and improve population health.