This nationwide study demonstrates an increased incidence of hypospadias diagnoses in Sweden from 1990 to 1999 that is not attributable to previously known risk factors. The increase includes mild and severe phenotypes, suggesting that shifts in the diagnostic criteria are not the underlying cause.

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.

Background Fertility in men with hypospadias may be affected due to anatomical, surgical, or etiological factors and associated conditions. Fertility is further influenced by psychosocial and genetic factors, often shared within families. Objective To evaluate fertility in men born with hypospadias and assess confounding by familial factors. Materials and methods A population‐based cohort of 1.2 million men born in Sweden 1964‐1998, identified through national demographic and healthcare registers. Associations between hypospadias and (a) being a biological father, (b) conceiving through ART, and (c) diagnosis of male infertility were investigated in the full cohort with logistic regression models and Cox proportional hazard models, expressed as odds ratios (ORs) and hazard ratios (HRs), respectively, with 95% confidence intervals (CIs). A stratified proportional hazard model, conditional on sibling group, was used to control for shared familial confounding. Results Men with hypospadias, as a whole group, had a lower probability of having biological children (adjusted HR 0.87, 95% CI 0.83‐0.92). A significant association was present in both distal (adjusted HR 0.90, 95% CI 0.85‐0.96) and proximal hypospadias (HR 0.59, 95% CI 0.42‐0.81). Men with hypospadias more often became fathers through ART, regardless of concomitant cryptorchidism. The initial association between hypospadias and the diagnosis of infertility disappeared in sensitivity analyses excluding cryptorchidism. Discussion Men with hypospadias displayed lower birthrates as compared to their brothers and the general population. Mere birthrates may, however, be a questionable measure of fertility in a population using family planning. However, men with hypospadias were also at higher risk of reproducing through ART and did more often receive a diagnosis of male infertility. Altogether, these findings indicate impaired fertility in men with hypospadias. Conclusions Fertility in men with hypospadias is impaired, as shown by lower birthrates, increased use of ART and higher risk of receiving a diagnosis of male infertility.

In this nationwide matched cohort study, we have investigated whether being born with hypospadias affect subsequent psychosocial outcomes in adulthood. We analyzed prospectively collected data from national Swedish registers. Data on the diagnoses were collected from the National Patient Register and the Medical Birth Register. Data on psychosocial outcomes such as educational and income level, marital status and disability pension were collected from Statistics Sweden. The effects of covariates, such as age, county of birth, presence of other malformations and psychiatric illness, were taken into account. The associations between hypospadias and psychosocial outcomes were calculated using conditional logistic regression and expressed as odds ratios (OR) and 95% confidence intervals (CI). We included 4378 men diagnosed with hypospadias, born between 1969 and 1993 in Sweden. Patients with hypospadias were matched with unaffected men by year of birth and birth county. We did not detect any differences in educational or income level. The probability of entering marriage (OR 1.02, 95% CI 0.90–1.14) did not differ, regardless of phenotype. We did, however, detect a 40% increased probability of receiving a disability pension, (OR 1.39, 95% CI 1.20–1.61). In conclusion, men born with hypospadias in Sweden do not differ from unaffected men with respect to the majority of psychosocial outcomes studied. They are, however, at increased risk of receiving a disability pension, which motivates further investigations.