The Estimated Prevalence of Hypospadias in Hokkaido, Japan

Identification of a novel candidate HSD3B2 gene variant for familial hypospadias by whole-exome sequencing

Introduction: Hypospadias [MIM: 300633] is one of the most frequent congenital malformations of male external genitalia. The spectrum of genetic variants causing hypospadias is varied, with studies commonly implicating genes critical in the fetal steroidogenic pathway. This is the first genetic study on hypospadias from the Yemen ethnicity and the second to report HSD3B2 mutations in more than one affected individual from the same family. Material and methods: Surgical hypospadias repair was performed on two hypospadias-affected siblings from a consanguineous family. Whole-exome sequencing (WES) was performed to identify the potential pathogenic variant for hypospadias, which was later confirmed by Sanger sequencing. The identified variant was further analyzed for its pathogenicity by using in silico tools such as SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf. Results: We identified a novel missense mutation (Chr1:119964631T>A, c.507T>A, p. N169K) in 3β-hydroxysteroid 2-dehydrogenase (HSD3B2) gene by WES. Sanger sequencing confirmed that the variant segregated the disease in the family between the affected and non-affected individuals. Both patients are homozygous, while parents and two unaffected siblings are heterozygous carriers, indicating an autosomal recessive pattern of inheritance. The in silico analysis by all six in silico tools (SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf) predicted the variant to be pathogenic/deleterious. Discussion: An abnormal fetal steroidogenic pathway due to genetic influences may affect the development of the male genital tract, including the urethral tract closure and morphogenesis of male genitalia. Furthermore, the pathogenicity of the observed variant in this study, confirmed by multiple in silico tools, characterizes the influence HSD3B2 gene variants may have in the etiology of hypospadias. Conclusion: Understanding of pathogenic manifestation and inheritance of confounding genetic variants in hypospadias is a matter of great concern, especially in familial cases.

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

Objectives

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

Study design

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

Results

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

Conclusion

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

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Hypospadias Prevalence and Trends in International Birth Defect Surveillance Systems, 1980-2010

BACKGROUND

Hypospadias is a common male birth defect that has shown widespread variation in reported prevalence estimates. Many countries have reported increasing trends over recent decades.

OBJECTIVE

To analyze the prevalence and trends of hypospadias for 27 international programs over a 31-yr period.

DESIGN, SETTING, AND PARTICIPANTS

The study population included live births, stillbirths, and elective terminations of pregnancy diagnosed with hypospadias during 1980-2010 from 27 surveillance programs around the world.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used joinpoint regression to analyze changes over time in international total prevalence of hypospadias across programs, prevalence for each specific program, and prevalence across different degrees of severity of hypospadias.

RESULTS AND LIMITATIONS

The international total prevalence of hypospadias for all years was 20.9 (95% confidence interval: 19.2-22.6) per 10000 births. The prevalence for each program ranged from 2.1 to 39.1 per 10000 births. The international total prevalence increased 1.6 times during the study period, by 0.25 cases per 10000 births per year (p<0.05). When analyzed separately, there were increasing trends for first-, second-, and third-degree hypospadias during the early 1990s to mid-2000s. The majority of programs (61.9%) had a significantly increasing trend during many of the years evaluated. Limitations include known differences in data collection methods across programs.

CONCLUSIONS

Although there have been changes in clinical practice and registry ascertainment over time in some countries, the consistency in the observed increasing trends across many programs and by degrees of severity suggests that the total prevalence of hypospadias may be increasing in many countries. This observation is contrary to some previous reports that suggested that the total prevalence of hypospadias was no longer increasing in recent decades.

PATIENT SUMMARY

We report on the prevalence and trends of hypospadias among 27 birth defect surveillance systems, which indicate that the prevalence of hypospadias continues to increase internationally.

Current work environments: What problems are being faced by Japanese urologists?

Computer technology has contributed to innovative progress in industrial infrastructures and has had a major influence on various work environments. Evaluations of work environments are routinely carried out in Western countries, but historically there has been resistance to such evaluations in Japan. In this mini-review, we discuss the current work environments of urologists in Japan. The number of urologists has increased each year, and the population density of urologists was 5.4 (per 100 000 people) in 2014. The average age of urologists in Japan was 48.9 years, and the percentage of female urologists was just 5.3%. Additionally, the geographic distribution of urologists was uneven in Japan. From projections based on population dynamics, the need for more urologists in the near future will probably increase. Because medical environments vary depending on the country, it is necessary to understand current work environments in greater detail initially. Furthermore, we should determine original measures for the establishment of satisfactory urological work environments in Japan.

Altitude as a risk factor for the development of hypospadias. Geographical cluster distribution analysis in South America

OBJECTIVE

Hypospadias is the most common congenital anomaly affecting the genitals. It has been established as a multifactorial disease with increasing prevalence. Many risk factors have been identified such as prematurity, birth weight, mother's age, and exposure to endocrine disruptors. In recent decades multiple authors using surveillance systems have described an increase in prevalence of hypospadias, but most of the published literature comes from developed countries in Europe and North America and few of the published studies have involved cluster analysis. Few large-scale studies have been performed addressing the effect of altitude and other geographical aspects on the development of hypospadias. Acknowledging this limitation, we present novel results of a multinational spatial scan statistical analysis over a 30-year period in South America and an altitude analysis of hypospadias distribution on a continent level.

METHOD

A retrospective review was performed of the Latin American collaborative study of congenital malformations (ECLAMC). A total of 4,020,384 newborns was surveyed between 1982 and December 2011 in all participating centers. We selected all patients with hypospadias. All degrees of clinical severity were included in the analysis. Each participating center was geographically identified with its coordinates and altitude above sea level. A spatial scan statistical analysis was performed using Kulldorf's methodology and a prevalence trend analysis over time in centers below and above 2000 m.

RESULTS

During the study period we found 159 hospitals in six different countries (Colombia, Bolivia, Brazil, Argentina, Chile, and Uruguay) with 4,537 cases of hypospadias and a global prevalence rate of 11.3/10,000 newborns. Trend analysis showed that centers below 2000 m had an increasing trend with an average of 10/10,000 newborns as opposed to those centers above 2000 m that showed a reducing trend with an average prevalence of 7.8 (p = 0.1246). We identified clusters with significant increases of prevalence in five centers along the coast at an average altitude of 219.8 m above sea level (p > 0.0000). Reduction in prevalence was found in clusters located in two centers on the Andes mountains. Altitude of 2,000 m was associated with hypospadias (Figure), with an OR 0.59 (0.5-0.69). There are ethnic arguments to support our results supported by protective polymorphism distribution in high lands.

CONCLUSION

Altitude above 2,000 m is suggested to have a protective effect for hypospadias. Specific clusters have been identified with increased risk for hypospadias. Environmental risk factors in these areas need to be further studied given the association seen between altitude and the distribution of more severe cases.

Association between SNP12 in estrogen receptor α gene and hypospadias: a systematic review and meta-analysis

To investigate the association between single nucleotide polymorphism 12 in estrogen receptor α gene and hypospadias, four databases (PubMed, Web of Science, Embase and Cochrane Library) were electronically searched by 2nd November 2015. Finally, four studies were included for our meta-analysis, involving 1379 cases and 1648 controls. A quality assessment was performed using the Newcastle–Ottawa Scale of case–control study. Meta-analysis and publication bias measuring were all done by Stata 12.0. No significant publication bias (P_Begg = 0.296, P_Egger = 0.161) was found. Overall, there was statistically significant association for recessive genetic model (AA vs. GA + GG: OR 3.45, 95 % CI [1.89, 6.30], P = 0.038). Moreover, the positive result was confirmed using trial sequential analysis even only three original studies. For allele model, there was also statistically significant association (allele A vs. G: OR 1.43, 95 % CI [1.23, 1.67], P = 0.034). Meanwhile, A allele as a risk factor turned out to be true positive by trial sequential analysis. In a word, this meta-analysis suggested that the single nucleotide polymorphism 12 definitely increase the risk of 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.

Sequencing of the DKK1 gene in patients with anorectal malformations and hypospadias

Anorectal malformations (ARM) are rare congenital malformations of the gastrointestinal tract. Approximately 60% of the patients have additional congenital malformations, such as hypospadias. A recently published article showed that deletion of one single gene, dickkopf WNT signaling pathway inhibitor-1 (Dkk1), resulted in an imperforate anus with rectourinary fistula and preputial hypospadias in mice. To determine whether DKK1 also plays a role in the etiology of ARM and hypospadias in humans, we sequenced the four exons of the DKK1 gene in 17 patients affected with both ARM and hypospadias. No new potential disease-causing variant was identified. However, we detected a known non-synonymous variant in one patient, which was predicted in silico to be damaging, and the corresponding unaffected amino acid is highly conserved.

CONCLUSION

In this human study, a potential interesting non-synonymous variant was found in the DKK1 gene. Whether this variant plays a contributory role in the genesis of ARM or hypospadias would require a much larger study.

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.

Environmental and genetic contributors to hypospadias: a review of the epidemiologic evidence

This review evaluates current knowledge related to trends in the prevalence of hypospadias, the association of hypospadias with endocrine-disrupting exposures, and the potential contribution of genetic susceptibility to its etiology. The review focuses on epidemiologic evidence. Increasing prevalence of hypospadias has been observed, but such increases tend to be localized to specific regions or time periods. Thus, generalized statements that hypospadias is increasing are unsupported. Owing to the limitations of study designs and inconsistent results, firm conclusions cannot be made regarding the association of endocrine-disrupting exposures with hypospadias. Studies with more rigorous study designs (e.g., larger and more detailed phenotypes) and exposure assessment that encompasses more breadth and depth (e.g., specific endocrine-related chemicals) will be critical to make better inferences about these important environmental exposures. Many candidate genes for hypospadias have been identified, but few of them have been examined to an extent that enables solid conclusions. Further study is needed that includes larger sample sizes, comparison groups that are more representative of the populations from which the cases were derived, phenotype-specific analyses, and more extensive exploration of variants. In conclusion, examining the associations of environmental and genetic factors with hypospadias remain important areas of inquiry, although our actual understanding of their contribution to hypospadias risk in humans is currently limited.

Aetiology of hypospadias: a systematic review of genes and environment

BACKGROUND

Hypospadias is a common congenital malformation of the male external genitalia. Most cases have an unknown aetiology, which is probably a mix of monogenic and multifactorial forms, implicating both genes and environmental factors. This review summarizes current knowledge about the aetiology of hypospadias.

METHODS

Pubmed was used to identify studies on hypospadias aetiology published between January 1995 and February 2011. Reference lists of the selected manuscripts were also searched to identify additional studies, including those published before 1995.

RESULTS

The search provided 922 articles and 169 articles were selected for this review. Studies screening groups of patients with hypospadias for single gene defects found mutations in WT1, SF1, BMP4, BMP7, HOXA4, HOXB6, FGF8, FGFR2, AR, HSD3B2, SRD5A2, ATF3, MAMLD1, MID1 and BNC2. However, most investigators are convinced that single mutations do not cause the majority of isolated hypospadias cases. Indeed, associations were found with polymorphisms in FGF8, FGFR2, AR, HSD17B3, SRD5A2, ESR1, ESR2, ATF3, MAMLD1, DGKK, MID1, CYP1A1, GSTM1 and GSTT1. In addition, gene expression studies indentified CTGF, CYR61 and EGF as candidate genes. Environmental factors consistently implicated in hypospadias are low birthweight, maternal hypertension and pre-eclampsia, suggesting that placental insufficiency may play an important role in hypospadias aetiology. Exogenous endocrine-disrupting chemicals have the potential to induce hypospadias but it is unclear whether human exposure is high enough to exert this effect. Other environmental factors have also been associated with hypospadias but, for most, the results are inconsistent.

CONCLUSIONS

Although a number of contributors to the aetiology of hypospadias have been identified, the majority of risk factors remain unknown.

The association between some endocrine disruptors and hypospadias in biological samples

Hypospadias is a birth defect found in boys in which the urinary tract opening is not at the tip of the penis. The etiology of hypospadias is still unidentified, but endocrine disruptors are considered as one possible cause of hypospadias. In this study, target endocrine disruptor compounds were established for an assay. The target compounds included 5 phthalates (di-(2-ethylhexyl)phthalate (DEHP), di-n-butyl-phthalate (DBP), mono-(2- ethylhexyl) phthalate (MEHP), mono-n-butyl-phthalate (MBP) and phthalic acid (PA)), 2 alkylphenols (n-nonylphenol (n-NP) and t-octylphenol (t-OP)) and bisphenol A. The association between these 8 endocrine disruptors and hypospadias was studied. The levels of endocrine disruptors in the urine and plasma of a control group were compared with those of a patient group. DEHP (P = 0.006) and n-NP (P = 7.26e-6) in the urine samples and PA (P = 0.009) and BPA (P = 7.22e-10) in the plasma samples showed a significant association with hypospadias. The levels of endocrine disruptors in the urine and plasma of the mothers were also compared to those of the patients to investigate the metastasis of the endocrine disruptors from the mother. These levels did not, however, show a relationship with hypospadias (R(2) = 0.001-0.563).

Hypospadias in Istanbul: incidence and risk factors

BACKGROUND

The aim of the present prospective study was to determine the incidence of hypospadias in newborns in one of the busiest teaching hospitals of Istanbul, and to investigate the risk factors.

METHODS

All live-born boys delivered between September 2007 and December 2008 were screened for hypospadias. A questionnaire was given to the parents of the hypospadias and control subjects for investigation.

RESULTS

Out of 1750 boys examined, 34 had hypospadias, that is, the frequency was 19.4 per 1000 male live-births and 93.7 per 10,000 total live-born deliveries. The incidence of additional coexistent anomalies was 29.4%, predominantly urogenital (17.6%), the majority of which were cryptorchidism (14.7%). Twelve (35.3%) of the 34 hypospadiac boys had a second family member with a genital anomaly, nine (26.5%) of whom had hypospadias, three (8.8%) being the fathers. Mean birthweight, length and head circumference were significantly lower in the hypospadiac infants than the control group (P= 0.003, P= 0.025, P= 0.002). Although parity, parental consanguinity, hypospadias in family members, and low birthweight also varied significantly among the groups, logistic regression analysis indicated that maternal age, prematurity, coexistence of cryptorchidism and presence of genital anomaly among family members were independent risk factors for hypospadias (P= 0.016, P= 0.0001, P= 0.041, P= 0.0001, respectively).

CONCLUSIONS

Genetic predisposition and placental insufficiency in early gestation might play a role in the etiology of hypospadias.

Time trends and geographic variations in the prevalence of hypospadias in China

BACKGROUND

Little is known about the main epidemiologic characteristics of hypospadias prevalence in China. We investigated the time trends and geographic variations in the prevalence of hypospadias in China from 1996 to 2008.

METHODS

Data were retrieved from the hospital-based birth defects monitoring system in China from 1996 to 2008. We used prevalence ratios (PRs) to describe the difference in prevalence of hypospadias between urban and rural areas, as well as among different regions. Poisson regression was used to explore the long time trend for the prevalence of hypospadias and its regional disparity.

RESULTS

The prevalences of hypospadias for isolated anomalies, multiple anomalies, and overall cases were 7.64, 1.39, and 9.03 per 10,000 births, respectively. The national PRs (urban vs. rural) of hypospadias for overall and isolated cases were 1.25 (95% confidence interval [CI], 1.16-1.35) and 1.27 (95% CI, 1.17-1.38), respectively. The highest prevalence (12.10 per 10,000 births) was observed in the eastern region. A positive correlation was found between the prevalence of hypospadias and maternal age (p < 0.01). The average annual increase of 7.43% (95% CI, 5.52-9.38%) was observed in the overall prevalence of hypospadias in China; it was 5.28% (95% CI, 4.16-6.43%) in urban areas, 9.79% (95% CI, 7.72-11.90%) in rural areas, 9.08% (95% CI, 6.36-11.86%) in the eastern region, 4.76% (95% CI, 2.93-6.62%) in the central region, and 6.57% (95% CI, 4.44-8.74%) in the western region.

CONCLUSION

The increasing trends and differences of hypospadias prevalence by urban-rural classification and geographical location suggest that environmental exposure and maternal age might have a critical role in the development of hypospadias.

Epidemiologic trends in penile anomalies and hypospadias in the state of California, 1985-2006

PURPOSE

Using statewide data, we evaluated whether the changing incidence of penile anomalies and hypospadias is reflected in the diverse California population of newborn males over the past 20 years.

METHODS

Discharge data from all California hospitals, prepared by the OSHPD (Sacramento, CA) was reviewed for the years 1985-2006 for male infant births with an ICD-9 code (752.6) for hypospadias, epispadias or other penile anomalies. Trends were examined by Generalized Estimation Equations for Poisson regression.

RESULTS

From 1985 to 2006, the birth incidence of newborn penile anomalies increased in California from 47 to 57 cases per 10,000 newborn discharges, yet the trend for hypospadias alone appears stable from 1997. The rates for penile anomalies in newborns increased 1.4% annually (p < 0.001). All racial/ethnic groups analyzed showed this increase (p < 0.001 for each). During the study period there was a 2% increase per year in plural births (p < 0.001). Interestingly, the rate of change in penile anomaly incidence was greater in males of plural births compared to their singleton cohorts (2% vs 1% annually) (p < 0.001). The birth incidence of cleft palate, another congenital anomaly known to be stable over time, remained unchanged over this period.

CONCLUSIONS

From 1985 to 2006 in California the incidence of penile anomalies increased in a statistically significant manner, but the incidence of hypospadias appears stable for the last decade. Our data support the notion that different racial/ethnic groups have distinct incidences of penile anomaly formation and that an association with plural births appears to be present.

[Profile and issues of prospective birth cohort in Japan]

Recently, the effects of environmental risk factors including chemical compounds and parents' lifestyles on the health of the next generations have widely gathered public concerns around the world because of the vulnerability of children to such environmental risk factors. To elucidate the processes and mechanisms of the effects in more detail, the authors started a prospective birth cohort study, namely, the Hokkaido study of Environment and Children's Health in Hokkaido, the northern area of Japan. The study consists of two cohorts: a large-scale cohort throughout Hokkaido and a hospital-based small-scale cohort. The former was established in 2003 in collaboration with forty obstetric hospitals and clinics around Hokkaido to estimate the prevalence of congenital malformations and investigate the association of congenital anomalies with environmental risk factors in pregnant mothers at a background level. The latter was lunched in 2002 at the time of enrollment of pregnant women recruited at an obstetric hospital in Sapporo so as to examine the relationships of environmental substances such as polychlorinated biphenyls (PCBs), dioxins, persistent organic pollutants (POPs), and heavy metals with infants' and children's health outcomes including birth size, neurobehavioral development, thyroid function, and immunologic system. In the study of both cohorts, we attempt to determine the role of gene polymorphism on the occurrence of adverse outcomes in infants and children. Although the prospective cohort study with well-designed epidemiological protocols may provide many scientific lines of evidence, many human and financial resources are required to support the study until its completion and maintain the biobanks as well as data banks. In Japan, it is urgently necessary to establish a system that supports the implementation and management of a cohort study.

Increasing prevalence of hypospadias in Western Australia, 1980-2000

OBJECTIVES

Hypospadias, a common birth defect, has shown widespread variation in reported rates and temporal trends across countries over the last 30 years. The aim of this study was to determine the prevalence and trends of hypospadias in an Australian population.

DESIGN

Population-based study of all male infants born in Western Australia (WA) between 1980 and 2000 diagnosed with hypospadias and notified to the WA Birth Defects Registry.

MAIN OUTCOME MEASURES

Prevalence of hypospadias, birth outcome and association with other congenital anomalies, stratified by degree-of-severity.

RESULTS

1788 cases of hypospadias were registered in WA in 1980-2000 with an overall prevalence of 34.8 (95% confidence interval (CI): 33.2 to 36.4) cases per 10 000 births. The prevalence increased by 2.0% per annum (95% CI: 1.2% to 2.8%) from 27.9 in 1980 to 43.2 per 10 000 births in 2000 (p<0.001). Hypospadias was mild in 84% of cases, moderate-severe in 11% and unspecified in 5%, with the number of moderate-severe hypospadias almost doubling over time (p<0.01). There were 1465 (82%) cases of isolated hypospadias and 323 (18%) had co-existing anomalies. Infants with co-existing genital (relative risk (RR) 4.5; 95% CI: 3.3 to 6.1) or non-genital (RR 1.5; 95% CI: 1.0 to 2.2) anomalies were more likely to have moderate-severe hypospadias compared with isolated cases.

CONCLUSION

Hypospadias affects one in 231 births and has been reported to have increased significantly over the last 20 years. Future investigation of the aetiology of hypospadias is important to identify potentially modifiable risk factors and ensure optimal male reproductive health in the future.

Dorsal inlay graft urethroplasty for primary hypospadiac repair

OBJECTIVE

Tubularized incised plate urethroplasty has become a popular technique for repairing distal and proximal hypospadias in many institutions. Dorsal inlay graft urethroplasty has been used in our institution since 2003 to reduce the risk of meatal stenosis. In the present study, we evaluated the results of the dorsal inlay graft procedure.

METHODS

A total of 28 patients with no deep groove and no severe curvature underwent one-stage urethroplasty using an inner preputial-based dorsal inlay graft. The medical records of all patients were retrospectively reviewed with regard to complication rate and cosmetic appearance.

RESULTS

Mean patient age at surgery was 21 months (range, 14 months to 4.6 years). Preoperatively the urethral meatus was coronal in two cases, distal shaft in 17, proximal shaft in six and penoscrotal in three. Nine patients required testosterone therapy before surgery. Mean operative time was 200 min (range, 154-249 min). Mean length of inlay graft was 20.9 mm (range, 12-30 mm). In all patients, a straight penis was achieved without dorsal plication of the corposa cavernosa, and the neomeatus with a slit-like appearance was positioned at the glans tip. At a mean of 22 months of follow up, a urethrocutaneous fistula developed in only one patient (3.6%), requiring repair surgery 6 months after urethroplasty. No patient had meatal stenosis, neourethral stricture or urethral diverticulum along the inlay graft.

CONCLUSION

Dorsal inlay graft urethroplasty is an effective method for hypospadiac repair and leads to good cosmetic outcome with low risk of complications.

Small for gestational age: short stature and beyond

Depending on the definitions used, up to 10% of all live-born neonates are small for gestational age (SGA). Although the vast majority of these children show catch-up growth by 2 yr of age, one in 10 does not. It is increasingly recognized that those who are born SGA are at risk of developing metabolic disease later in life. Reduced fetal growth has been shown to be associated with an increased risk of insulin resistance, obesity, cardiovascular disease, and type 2 diabetes mellitus. The majority of pathology is seen in adults who show spontaneous catch-up growth as children. There is evidence to suggest that some of the metabolic consequences of intrauterine growth retardation in children born SGA can be mitigated by ensuring early appropriate catch-up growth, while avoiding excessive weight gain. Implicitly, this argument questions current infant formula feeding practices. The risk is less clear for individuals who do not show catch-up growth and who are treated with GH for short stature. Recent data, however, suggest that long-term treatment with GH does not increase the risk of type 2 diabetes mellitus and the metabolic syndrome in young adults born SGA.

Maternal genetic polymorphisms in CYP1A1, GSTM1 and GSTT1 and the risk of hypospadias

Hypospadias is one of the most common congenital anomalies. Increased exposure to environmental factors (endocrine-disrupting chemicals and smoking) or maternal endogenous estrogen may cause hypospadias because male sexual differentiation is dependent on normal androgen homeostasis. Moreover, interactions between genetic factors and cigarette smoking and other chemicals have been suggested. It has been demonstrated that the CYP1A1 metabolizes not only environmental chemicals but also estrogens, and glutathione-S-transferases (GSTs) are detoxification enzymes that protect cells from toxicants by conjugation with glutathione. In this study, to investigate the association of CYP1A1 (MspI), GSTM1 and GSTT1 polymorphisms with hypospadias, a case-control study of 31 case mothers who had boys with hypospadias and 64 control mothers was performed in Japan. These polymorphisms were investigated by PCR-based methods using DNA from peripheral lymphocytes. We found that the heterozygous CYP1A1 and heterozygous and homozygous CYP1A1 were less frequent in the case mothers than in the control mothers [adjusted odds ratio (OR)=0.17, 95% confidence interval (CI)=0.04-0.74, OR = 0.28, 95% CI = 0.08-0.97, respectively]. We found no effect of maternal smoking on the hypospadias risks among the gene polymorphisms. The results suggest that mothers with the CYP1A1 MspI variant allele may have a decreased risk for hypospadias.