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

Abstract

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.

Keywords: Hypospadias; International Clearinghouse for Birth Defects Surveillance and Research; Joinpoint regression; Prevalence; Trend.

Fig. 1 -

Total prevalence of hypospadias (per 10 000) for International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) programs, grouped by world region, 1980–2010 and 2000–2010.

Fig. 2 -

Trends in the International total prevalence of hypospadias among ICBDSR programs with select characteristics using joinpoint regression, 1980–2010. ^a (A) Among 19 programs with (1) population-based ascertainment, (2) age of ascertainment ≥1 yr, and (3) ascertainment from multiple sources. (B) Among eight programs with (1) population-based ascertainment, (2) age of ascertainment ≥1 yr, (3) ascertainment from multiple sources, and (4) at least 30 yr of data. (C) Results by program, among eight programs with (1) population-based ascertainment, (2) age of ascertainment ≥1 yr, (3) ascertainment from multiple sources, and (4) at least 30 yr of data. ICBDSR= International Clearinghouse for Birth Defects Surveillance and Research. ^a Stars indicate joinpoints with statistically significant (p < 0.05) trends.

Fig. 3 -

Trends in the International total prevalence of hypospadias for 12 ICBDSR programs by clinica! degree of severity, 1980–2010 ^a,b: (A) First-degree hypospadias, (B) second-degree hypospadias, and (C) third-degree hypospadias. ICBDSR = International Clearinghouse for Birth Defects Surveillance and Research. ^a Stars indicate joinpoints with statistically significant (p < 0.05) trends. ^b Programs for which the degree of severity was unspecified in ≥80% of cases were excluded.