Epidemiological Assessment of Hypospadias by Degree of Severity

Efficacy comparison between Mathieu combined urethral plate incision and onlay island flap urethroplasty for distal hypospadias in patients with urethral plate stenosis

ABSTRACT

The aim of the study was to compare the efficacy of Mathieu combined urethral plate incision (Mathieu-IP) versus onlay island flap urethroplasty in patients with distal hypospadias complicated by urethral stenosis. The clinical data of 70 patients with distal hypospadias complicated by urethral plate stenosis treated in the Department of Urology, Anhui Provincial Children's Hospital (Hefei, China), from May 2019 to May 2022, were retrospectively analyzed. Thirty-eight patients underwent Mathieu-IP (Mathieu-IP group) and 32 underwent onlay island flap urethroplasty (Onlay group). Follow-ups at 1 month, 6 months, and 12 months postoperatively assessed operative time, complications, urethral meatus morphology, and family satisfaction. The Mathieu-IP group had significantly shorter operative time (mean ± standard deviation [s.d.]: 81.58 ± 5.18 min) versus the Onlay group (mean ± s.d.: 110.75 ± 6.05 min; P < 0.05). Surgical success rates were 78.9% (Mathieu-IP group) and 75.0% (Onlay group), with no significant difference (P > 0.05). Complications were comparable between the groups. The Mathieu-IP group resulted in a vertical slit-shaped urethral meatus in 89.5% versus 13.8% in the Onlay group (P < 0.05). Family satisfaction with general penile appearance and skin shape showed no significant differences, but the Mathieu-IP group had higher satisfaction with meatal position (P < 0.05). Mathieu-IP offers simplicity, safety, and shorter operative time compared to Onlay. Both the techniques effectively treat urethral plate stenosis in distal hypospadias, with reduced postoperative complications compared to tubularized incised plate urethroplasty. Mathieu-IP results in a vertical slit-shaped urethral meatus which enhances urinary stream, indicating its potential for broader adoption.

Hypospadias prevalence by severity and associated risk factors: A population-based active surveillance analysis

INTRODUCTION

Hypospadias is one of the most common congenital anomalies. Trends of hypospadias prevalence by severity are not well reported. Most prevalence studies consist of pooled data from different countries or states suffer from low data quality due to inconsistent methodologies, limited variables, and lack of categorization of hypospadias severity.

OBJECTIVE

The objective of this study is to examine the prevalence of hypospadias by degrees of severity and associated risk factors using combined data sources from a stable and well-defined population.

STUDY DESIGN

The study population includes infants born with hypospadias to mothers residing in Arkansas from 1997 to 2016. Cases were identified from an active population-based surveillance program of birth defects. Identified hypospadias cases from surveillance data were linked to birth certificate and to a clinical database. These two data sources provide more details on the location of the defect and maternal and infant characteristics. The prevalence and 95% confidence intervals were calculated using total male live births as denominator. Chi-square test was used to assess the association of nominal variables. Logistic regression was used to calculate adjusted odds ratio.

RESULTS

A total 3230 hypospadias cases were identified from 1997 to 2016. The overall prevalence is 83.0 per 10,000 male births. A majority of cases (56.7%) were classified as first degree with the others having second degree (22.8%), third degree (4.7%) or not otherwise specified (15.6%). The highest prevalence of hypospadias was observed among Non-Hispanic whites. Higher prevalence also was observed among mothers in the older age group with no prenatal care in the first trimester and with gestational hypertension or diabetes. Premature or small for gestational age infants tend to have higher prevalence across all levels of severity. The number of hypospadias cases increased over time. After maternal age, race and education were adjusted, higher risk persisted for infants of restricted fetal growth, mothers with gestational hypertension or diabetes and the cohort of 2013-2016.

CONCLUSION

There is an increase of hypospadias cases in Arkansas. Several maternal and infant characteristics associated with higher prevalence for all levels of severity are worth further investigation.

Prevalence and Clustering of Congenital Heart Defects Among Boys With Hypospadias

IMPORTANCE

Hypospadias is a common birth defect of the male urinary tract that may be isolated or may co-occur with other structural malformations, including congenital heart defects (CHDs). The risk for co-occurring CHDs among boys with hypospadias remains unknown, which limits screening and genetic testing strategies.

OBJECTIVE

To characterize the risk of major CHDs among boys born with hypospadias.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from population-based birth defect surveillance programs on all male infants born in 11 US states from January 1, 1995, to December 31, 2014. Statistical analysis was performed from September 2, 2020, to March 25, 2022.

EXPOSURE

Hypospadias.

MAIN OUTCOMES AND MEASURES

Demographic and diagnostic data were obtained from 2 active state-based birth defect surveillance programs for primary analyses, the Texas Birth Defects Registry and the Arkansas Reproductive Health Monitoring System, with validation among 9 additional states in the National Birth Defects Prevention Network (NBDPN). Birth defect diagnoses were identified using the British Pediatric Association coding for hypospadias (exposure) and major CHDs (primary outcomes). Maternal covariates and birth year were also abstracted from the vital records. Poisson regression was used to estimate adjusted prevalence ratios and 95% CIs for major CHDs within Texas and Arkansas and combined using inverse variance-weighted meta-analysis. Findings were validated using the NBDPN.

RESULTS

Among 3.7 million pregnancies in Texas and Arkansas, 1485 boys had hypospadias and a co-occurring CHD. Boys with hypospadias were 5.8 times (95% CI, 5.5-6.1) more likely to have a co-occurring CHD compared with boys without hypospadias. Associations were observed for every specific CHD analyzed among boys with hypospadias, occurred outside of chromosomal anomalies, and were validated in the NBDPN. An estimated 7.024% (95% CI, 7.020%-7.028%) of boys with hypospadias in Texas and 5.503% (95% CI, 5.495%-5.511%) of boys with hypospadias in Arkansas have a co-occurring CHD. In addition, hypospadias severity and maternal race and ethnicity were independently associated with the likelihood for hypospadias to co-occur with a CHD; boys in Texas with third-degree (ie, more severe) hypospadias were 2.7 times (95% CI, 2.2-3.4) more likely than boys with first-degree hypospadias to have a co-occurring CHD, with consistent estimates in Arkansas (odds ratio, 2.7; 95% CI, 1.4-5.3), and boys with hypospadias born to Hispanic mothers in Texas were 1.5 times (95% CI, 1.3-1.8) more likely to have a co-occurring CHD than boys with hypospadias born to non-Hispanic White mothers.

CONCLUSIONS AND RELEVANCE

In this cohort study, boys with hypospadias had a higher prevalence of CHDs than boys without hypospadias. These findings support the need for consideration of additional CHD screening programs for boys born with hypospadias.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Endocrine-Disrupting Chemicals and Disorders of Penile Development in Humans

This paper reviews the current knowledge on the environmental effects on penile development in humans. The specific focus is on endocrine-disrupting chemicals (EDCs), a heterogeneous group of natural or manmade substances that interfere with endocrine function, and whether they can induce hypospadias and micropenis in male neonates. Epidemiological data and animal observations first raised suspicions about environmental effects, leading to the testis dysgenesis syndrome (TDS) hypothesis. More recent research has provided stronger indications that TDS may indeed be the result of the direct or indirect effects of EDCs. Drawing on epidemiological and toxicological studies, we also report on the effects of maternal diet and substances like pesticides, phthalates, bisphenol A, and polychlorinated biphenyls. Proximity to contamination hazards and occupational exposure are also suspected to contribute to the occurrence of hypospadias and micropenis. Lastly, the cumulative effects of EDCs and the possibility of transgenerational effects, with the penile development of subsequent generations being affected, raise concerns for long-term public health.

Expression of Mafb is down-regulated in the foreskin of children with hypospadias

BACKGROUND

Hypospadias is the second most common congenital malformation in males. Although the aetiology of hypospadias is not clear, it is generally thought to be affected by both genetic and environmental endocrine-disrupting factors that affect the development of the urethra, leading to deformity.

OBJECTIVE

To investigate the difference in expression of the transcription factor Mafb in hypospadias and normal penile tissues and to assess whether it is related to the occurrence of hypospadias.

STUDY DESIGN

Penile tissue was obtained from children with hypospadias who underwent surgical repair at the Children's Hospital of Chongqing Medical University. Patients diagnosed with undescended testicles, intersex status or endocrine abnormalities were excluded from the study. Twenty-five cases with hypospadias (average 3.5 years old) and 15 cases with circumcisions (as control) (average 5 years old) were included in this study. Real-time quantitative polymerase chain reaction, Immunochemistry and Western blot were used to detect the expression of Mafb.

RESULTS

Mafb mRNA expressions in the prepuce of cases with hypospadias was significantly reduced compared with that in the controls [(1.179 ± 0.1275), (0.6652 ± 0.07506), p < 0.05)]. Hypospadias cases also showed decreased Mafb protein expression in the preputial subcutaneous mesenchymal cell layer. Mafb protein levels were significantly decreased in those with hypospadias compared with controls [(1.932 ± 0.1139), (1.006 ± 0.03312), p < 0.05]. However, no such differences were found in Mafb expression between subjects with mild and severe hypospadias.

DISCUSSION

Compared to the normal foreskin, expression of the Mafb gene was down-regulated at both mRNA and protein levels, which was consistent with our RNA-seq sequencing results in Diethylhexyl phthalate (DEHP)-induced hypospadias rats. This study is the first to report abnormal expression of Mafb in the preputial tissue of hypospadias cases. An in-depth study of the relationship between Mafb and cell proliferation, apoptosis, and urethra development may reveal the pathogenesis of hypospadias.

CONCLUSION

Expression of the Mafb gene and protein in the foreskin of children with hypospadias is lower than that in normal foreskin. We postulate that such abnormal expression of the Mafb gene may be related to the occurrence of hypospadias and that this abnormal expression may affect the development of the urethra during the embryonic period.

Altered mechanisms of genital development identified through integration of DNA methylation and genomic measures in hypospadias

Hypospadias is a common birth defect where the urethral opening forms on the ventral side of the penis. We performed integrative methylomic, genomic, and transcriptomic analyses to characterize sites of DNA methylation that influence genital development. In case–control and case-only epigenome-wide association studies (EWAS) of preputial tissue we identified 25 CpGs associated with hypospadias characteristics and used one-sample two stage least squares Mendelian randomization (2SLS MR) to show a causal relationship for 21 of the CpGs. The largest difference was 15.7% lower beta-value at cg14436889 among hypospadias cases than controls (EWAS P = 5.4e−7) and is likely causal (2SLS MR P = 9.8e−15). Integrative annotation using two-sample Mendelian randomization of these methylation regions highlight potentially causal roles of genes involved in germ layer differentiation (WDHD1, DNM1L, TULP3), beta-catenin signaling (PKP2, UBE2R2, TNKS), androgens (CYP4A11, CYP4A22, CYP4B1, CYP4X1, CYP4Z2P, EPHX1, CD33/SIGLEC3, SIGLEC5, SIGLEC7, KLK5, KLK7, KLK10, KLK13, KLK14), and reproductive traits (ACAA1, PLCD1, EFCAB4B, GMCL1, MKRN2, DNM1L, TEAD4, TSPAN9, KLK family). This study identified CpGs that remained differentially methylated after urogenital development and used the most relevant tissue sample available to study hypospadias. We identified multiple methylation sites and candidate genes that can be further evaluated for their roles in regulating urogenital development.

Megameatus intact prepuce treated with urethral plate-preserving surgery: a retrospective study of an unusual hypospadias variant

BACKGROUND

Megameatus intact prepuce (MIP) is a unique variant of hypospadias and is a clinically rare condition. Due to the anatomical characteristics of the MIP hypospadias variant presenting a unique challenge to surgeons, no single urethroplasty method provides a universal solution for all patients. The purpose of this study was to evaluate the outcomes of hypospadias after MIP repair by urethral plate-preserving urethroplasty.

METHODS

A retrospective study was performed on 25 coronal or distal MIP patients, with a median age of 8, with most deficiencies being discovered during their first hospital visit for phimosis. Correction with urethroplasty was performed for all patients; 5 underwent the Mathieu procedure, 13 underwent the tubularized incised plate (TIP) procedure, and 7 underwent the Duplay procedure. The 25 patients were followed up for 6 to 36 months to evaluate the surgical outcomes.

RESULTS

There were no significant differences in intraoperative bleeding, hospital stays, postoperative analgesia rate, and cure rate among the three surgical procedures. The operative time for the Mathieu procedure was longer than that for the TIP and Duplay procedures, which did not differ. Complications occurred in 4 of the 25 patients (16.0%), and the overall complication-free survival rate at 1 year after surgery was 80.5%. The age at the time of surgery, urethral plate width, urethroplasty length, surgical procedures, or meatal location (coronal or distal penis) were not independently predictive of complications.

CONCLUSIONS

The clinical manifestations of MIP are often concealed and then accidentally discovered during hospital visits for phimosis; thus, the actual incidence of MIP might be higher. The urethral plate should be preserved during MIP-correcting treatment, especially for coronal or distal MIP. The same satisfactory outcomes can be obtained with Mathieu, TIP, or Duplay urethroplasty.

The role of genetic variation in DGKK on moderate and severe hypospadias

BACKGROUND

Recent genome-wide association studies of hypospadias have implicated the role of genetic variants in or near the diacylglycerol kinase kappa (DGKK) gene. However, these variants are largely identified among samples of mild and moderate hypospadias cases. Therefore, we evaluated previously identified DGKK variants among second- and third-degree hypospadias cases and controls recruited in Arkansas, a state characterized by a high birth prevalence of hypospadias.

METHODS

Second- and third-degree hypospadias non-Hispanic white cases (n = 36 and n = 9, respectively) and controls (n = 45) were recruited at Arkansas Children's Hospital. Preputial tissue was collected on cases and controls between 2013 and 2017. Cases and controls were genotyped using the Illumina Infinium Global Screening Array. We used logistic regression models to assess the association of genotyped and imputed genetic variants mapped to the DGKK region with second- and third-degree hypospadias.

RESULTS

All families self-reported as non-Hispanic white and genetic principal component analyses did not demonstrate evidence of population stratification. Five DGKK variants previously reported as associated with hypospadias were identified in the genotype data. None of the variants were associated with second- or third-degree hypospadias (range of odds ratios = 0.7-0.9, all p > .05).

CONCLUSIONS

In our analyses, genetic variation in DGKK does not play a role in the development of moderate and severe hypospadias. Our findings provide support to the etiologic heterogeneity of hypospadias by all classifications of severity.

Hypospadias Risk from Maternal Residential Exposure to Heavy Metal Hazardous Air Pollutants

Objective: Investigate whether residential prenatal exposure to heavy metal hazardous air pollutants (HMHAPs) is associated with an increased risk of hypospadias. Methods: Data on non-syndromic hypospadias cases (n = 8981) and control patients delivered in Texas were obtained from the Texas Birth Defects Registry and matched 1:10 by birth year. Average exposure concentrations of HMHAPs were obtained from the 2005 U.S. Environmental Protection Agency National-Scale Air Toxics Assessment and categorized into quintiles. Odds ratios and 95% confidence intervals were estimated. STROBE reporting guidelines were followed. Results: We observed associations between hypospadias and prenatal HMHAP exposure. Manganese demonstrated significant increased risk of hypospadias at the medium, medium-high and high exposure quintiles; lead in the medium-high and high exposure quintiles. Cadmium, mercury and nickel demonstrated a significant inverted "U-shaped" association for exposures with significant associations in the medium and medium-high quintiles but not in the medium-low and high quintiles. Arsenic and chromium demonstrated a significant bivalent association for risk of hypospadias in a lower quintile as well as a higher quintile with non-significant intermediate quintiles. Conclusions: Using data from one of the world's largest active surveillance birth defects registries, we identified significant associations between hypospadias and HMHAP exposures. These results should be used in counseling for maternal demographic risk factors as well as avoidance of heavy metals and their sources.

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.

Epithelial-mesenchymal transformation and apoptosis in rat urethra development

BackgroundTo examine the mechanism of urethral seam formation during embryonal development of rat urethra.MethodsTime-mated Sprague-Dawley rats were killed and the genital tubercles of male pups harvested on embryonic day (ED) 15, 16, 18, and 19. External morphology was observed under scanning electron microscope. Serial transverse sections were prepared to examine dynamic changes in the urethral seam morphology with hematoxylin-eosin staining, immunohistochemistry, transmission electron microscopy, and double immunofluorescence.ResultsBilateral outgrowth of urethral swelling followed by urethral plate fusion in the midline to form urethral seam was observed from ED 16 onwards. Coexpression of epithelial and mesenchymal markers was observed in several cells at the urethral seam; a few cells with coexpression of epithelial and apoptotic markers were also observed. Mesenchymal transformation of epithelial cells and apoptotic epithelial cells was observed under transmission electron microscope.ConclusionUrethral formation occurs by tubulogenesis, which initiates proximally and progresses distally. This is the first study to demonstrate epithelial-mesenchymal transformation and epithelial cell apoptosis in the urethral seam cells of fetal rats. These findings provide new insights into the mechanisms involved in embryonal development of the urethra.

In pursuit of the perfect penis: Hypospadias repair outcomes

Hypospadias is commonly assessed and repaired by pediatric urologists. Mild, distal hypospadias is generally more a cosmetic problem than a functional one and is more frequently encountered than severe, proximal hypospadias. Outcomes following repair, especially of mild phenotypes, are important to understand, but range widely in timing and measurability. Surgical complications, postoperative satisfaction of parents, patients, surgeons and even lay observers, urinary function, sexual function, and quality of life all may be considered as relevant outcomes of hypospadias repair. Existing studies examining these outcomes are diverse in their conclusions, but are important to understand when counseling parents and patients prior to any surgical intervention.

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.

Shorter anogenital and anoscrotal distances correlate with the severity of hypospadias: A prospective study

INTRODUCTION

Anogenital distance (AGD) is a recognised marker of in utero androgen action.

OBJECTIVE

This study aimed to evaluate the relationship between severity of hypospadias and AGD.

STUDY DESIGN

Boys undergoing hypospadias repair in a single tertiary centre between May 2012 and February 16 were included in the study. Anogenital distance was measured from the centre of the anus to the base of the penis, and anoscrotal distance (ASD) from the centre of the anus to the junction between the smooth perineal skin and scrotal skin. Trained paediatric urologists made all measurements using digital callipers.

RESULTS

Fifty-nine boys with hypospadias and 31 age-matched controls undergoing circumcision (median age 1.37 years, range 1.01-1.96) had AGD and ASD measured under anaesthetic. The patients were divided into two groups, according to hypospadias severity: group 1 - distal penile/subcoronal/glandular (n = 40); and group 2 - perineal/penoscrotal/midshaft (n = 19). The median AGD for controls was 74.0 mm (range 53.2-87.8) and for hypospadias it was 72.3 mm (range 50.7-90.0) (P = 0.816). The median ASD for controls was 42.3 mm (range 31.0-56.1) and for hypospadias it was 39.4 mm (range 20.7-77.0) (P = 0.224). Considering severity of hypospadias, the median AGD for group 1 and group 2 was 73.7 mm (range 50.7-90.0) and 63.3 mm (range 53.6-77.0), respectively (P < 0.001). The median ASD was also higher in group 1, at 41.3 mm (range 20.7-65.0), compared to 35.2 mm (range 23.5-77.0) in group 2 (P = 0.119) (Summary Fig.).

DISCUSSION

This study showed that more severe forms of hypospadias are associated with shorter AGD and ASD. These findings agree with two previous studies that identified reduced AGD in boys with hypospadias. However, these studies did not investigate an association with severity of hypospadias. As hypospadias is multifactorial, only a small proportion of cases are thought to be associated with impaired in utero androgen exposure. The shorter AGD in boys with severe hypospadias compared with mild hypospadias would indicate that AGD is a marker of the severity of androgen production. This may also suggest that less severe forms of hypospadias have a different aetiology involving a later stage of development, and that they are not the result of reduced androgen exposure in the male programming window between the 8-14 weeks gestation.

CONCLUSION

This study identified that boys with more severe hypospadias are more likely to have a shorter AGD and ASD than boys with mild hypospadias. This may indicate that there is a more profound impairment of in utero androgen action in severe hypospadias.

Prevalence, repairs and complications of hypospadias: an Australian population-based study

OBJECTIVE

To investigate hypospadias' prevalence and trends, rate of surgical repairs and post-repair complications in an Australian population.

METHODS

Hypospadias cases were identified from all live-born infants in New South Wales, Australia, during the period 2001-2010, using routinely collected birth and hospital data. Prevalence, trends, surgical procedures or repairs, hospital admissions and complications following surgery were evaluated. Risk factors for reoperation and complications were assessed using multivariate logistic regression.

RESULTS

There were 3186 boys with hypospadias in 2001-2010. Overall prevalence was 35.1 per 10,000 live births and remained constant during the study period. Proportions of anterior, middle, proximal and unspecified hypospadias were 41.3%, 26.2%, 5.8% and 26.6%, respectively. Surgical procedures were performed in 1945 boys (61%), with 1718 primary repairs. The overall post-surgery complication rate involving fistulas or strictures was 13%, but higher (33%) for proximal cases. Complications occurred after 1 year post-repair in 52.3% of cases and up to 5 years. Boys with proximal or middle hypospadias were at increased risk of reoperation or complications, but age at primary repair did not affect the outcome.

CONCLUSION

One in 285 infants were affected with hypospadias, 60% required surgical repair or correction and one in eight experienced complications. The frequency of late complications would suggest that clinical review should be maintained for >1 year post-repair.

A modified onlay island flap vs. Mathieu urethroplasty for distal hypospadias repair: A prospective randomised study

OBJECTIVE

To compare the outcome of a modified onlay island flap (MOIF) with that of the Mathieu urethroplasty for distal hypospadias repair.

PATIENTS AND METHODS

In a prospective randomised study, 60 patients with coronal, subcoronal and distal penile hypospadias, with a urethral plate width of ⩽6 mm, and minimal or no chordee, underwent either MOIF using a midline longitudinal outer preputial skin flap passed ventrally by penile buttonholing through dartos fascia incision, or a Mathieu urethroplasty. Closed envelopes were used for randomly selecting patients for each procedure. The operative duration, complications, cosmetic outcome, urinary stream and relatives' satisfaction were reported for each procedure.

RESULTS

Preoperative data (patients' age and site of urethral meatus) and operative duration were insignificantly different between the groups (P = 0.653, 0.786 and 0.710, respectively). There were no intraoperative complications in either group. The duration of follow-up was insignificantly different between the groups. Patients treated with the MOIF had a statistically significant lower complication rate (P = 0.036), and a better cosmetic outcome, urinary stream and relatives' satisfaction (P < 0.001 for all).

CONCLUSIONS

The MOIF urethroplasty seemed to be better than the Mathieu urethroplasty in patients with distal hypospadias and narrow urethral plates. Further studies including more patients, and a longer follow-up with an objective evaluation of functional outcome should be encouraged to confirm these early results.

Epidemiology of hypospadias in Europe: a registry-based study

Background

Hypospadias is a common congenital malformation. The prevalence of hypospadias has a large geographical variation, and recent studies have reported both increasing and decreasing temporal trends. It is unclear whether hypospadias prevalence is associated with maternal age.

Aim

To analyze the prevalence and trends of total hypospadias, isolated hypospadias, hypospadias with multiple congenital anomalies, hypospadias with a known cause, and hypospadias severity subtypes in Europe over a 10-year period and to investigate whether maternal age is associated with hypospadias.

Methods

We included all children with hypospadias born from 2001 to 2010 who were registered in 23 EUROCAT registries. Information on the total number of births and maternal age distribution for the registry population was also provided. We analyzed the total prevalence of hypospadias and relative risks by maternal age.

Results

From 2001 to 2010, 10,929 hypospadias cases were registered in 5,871,855 births, yielding a total prevalence of 18.61 per 10,000 births. Prevalence varied considerably between different registries, probably due to differences in ascertainment of hypospadias cases. No significant temporal trends were observed with the exceptions of an increasing trend for anterior and posterior hypospadias and a decreasing trend for unspecified hypospadias. After adjusting for registry effects, maternal age was not significantly associated with hypospadias.

Conclusions

Total hypospadias prevalence was stable in 23 EUROCAT registries from 2001 to 2010 and was not significantly influenced by maternal age.

Intrauterine growth restriction and hypospadias: is there a connection?

Hypospadias is one of the most common congenital malformations of the genitourinary tract in males. It is an incomplete fusion of urethral folds early in fetal development and may be associated with other malformations of the genital tract. The etiology is poorly understood and may be hormonal, genetic, or environmental, but most often is idiopathic or multifactorial. Among many possible risk factors identified, of particular importance is low birth weight, which is defined in various ways in the literature. No mechanism has been identified for the association of low birth weight and hypospadias, but some authors propose placental insufficiency as a common inciting factor. Currently, there is no standardized approach for evaluating children with hypospadias in the setting of intrauterine growth restriction. We reviewed the available published literature on the association of hypospadias and growth restriction to determine whether it should be considered a separate entity within the category of disorders of sexual differentiation.

Long-term followup of men born with hypospadias: urological and cosmetic results

PURPOSE

We present data on long-term functional and cosmetic results after hypospadias surgery.

MATERIALS AND METHODS

Males older than 18 years with hypospadias treated in Sweden were asked to participate in the study, as well as age matched controls and circumcised men. All participants answered questionnaires, and a subgroup was examined during an outpatient visit. Relationships with outcome were analyzed using analysis of variance and regression analysis.

RESULTS

A total of 167 patients with a mean age of 34 years and 169 controls with a mean age of 33 years answered the questionnaire. Of the patients 63% had distal, 24% mid and 13% proximal hypospadias. A total of 46 patients and 49 controls presented for physical examination. Patients were significantly less satisfied with the penile cosmetic outcome regarding all parameters of the Penile Perception Score. There was a difference in penile length between patients and controls (mean 9.7 vs 11.6 cm, p <0.001). More patients than controls reported voiding dysfunction symptoms (p = 0.003). Patients had a lower maximum urinary flow rate than controls (p = 0.001). These differences were most prominent between patients with proximal hypospadias and controls.

CONCLUSIONS

Men operated on for hypospadias were less satisfied with the cosmetic result than controls, and had a shorter penile length. Patients presented with more symptoms of voiding dysfunction and displayed a lower maximum urinary flow rate. Patients with proximal hypospadias were more affected than those with milder hypospadias. Our results indicate that patients with hypospadias can be subgrouped and that those with severe phenotypes should be followed more closely during childhood as well as later in adulthood.

Genetic and environmental origins of hypospadias

PURPOSE OF REVIEW

The purpose of this study was to review and comment on recent original presentations dealing with genetic and environmental factors in the cause of hypospadias.

RECENT FINDINGS

The heritability is definitely high and having an affected family member is the highest identified risk factor so far. Many candidate genes and polymorphisms have been suggested for hypospadias. Some associations with hypospadias were found, and many of these were replicated inconsistently as would be expected in a complex disorder affected by both genes and environment. The consistent association of hypospadias with low birth weight, maternal hypertension, and preeclampsia suggests that placental insufficiency is a major risk factor. Maternal exposure to chemical pollutants or endocrine disruptors in high concentrations related to selected occupations or geographic areas may be additional risk factors for hypospadias, especially in genetically predisposed individuals. So far, however, no environmental chemical pollutants or endocrine disruptor with a general common impact on the risk for hypospadias in most societies has been demonstrated.

SUMMARY

A major point that should be considered regarding the action of environmental toxicants in inducing hypospadias is the cumulative effects of multiple low-dose exposures. Furthermore, interactions between genetic and environmental factors may help to explain nonreplication in genetic studies of hypospadias.

Epidemiologic features of male genital malformations and subtypes in Texas

Although distinct categories of male genital malformations share some common risk factors, few studies have systematically compared epidemiologic features across phenotypes. We evaluated the relationship between several maternal and infant characteristics and five categories of male genital malformations: second- or third-degree hypospadias, hypospadias (regardless of degree), small penis, cryptorchidism, and any male genital malformation. Data for 16,813 cases with isolated male genital malformations and 1,945,841 male live births delivered from 1999 to 2008 were obtained from the Texas Birth Defects Registry. For each phenotype category, 13 maternal and infant variables were assessed, and adjusted prevalence ratios were estimated based on the same multivariable Poisson regression model. A significant negative association was observed between previous live births versus no previous live births and four phenotypes (e.g., adjusted prevalence ratio [aPR] for any male genital malformation: 0.78, 95% confidence interval [CI]: 0.75-0.81). The prevalence of 4 of the phenotypes was significantly higher among multiple versus singleton pregnancies (e.g., aPR for any male genital malformation: 1.35, 95% CI: 1.25-1.47). We also observed significant associations between multiple phenotypes and residential region at delivery, delivery year, month of conception, and maternal age, race/ethnicity, education, and birthplace, including significant associations for trends (maternal age, maternal education, and birth year modeled ordinally). Our results allow for comparison of characteristics across phenotypes and suggest that there may be some common risk factors for multiple male genital malformations (e.g., characteristics related to maternal estrogen levels), while other risk factors may be unique to specific defects.