ESPU Congress 2018 - Abstract Book

77 11–14 APRIL, 2018, HELSINKI, FINLAND 11:48–11:51 S8-2 (PP) ★ FERTILITY IN HYPOSPADIAS: A NATIONWIDE REGISTER- BASED COHORT STUDY WITH SIBLING ANALYSIS Anna SKARIN NORDENVALL  1 , Christina NORRBY  2 , Qi CHEN  2 , Louise FRISÉN  3 , Anna NORDENSTRÖM  1 , Catarina ALMQVIST  2 and Agneta NORDENSKJÖLD  1 1) Karolinska Institutet, Department of women's and children's health, Stockholm, SWEDEN - 2) Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Stockholm, SWEDEN - 3) Karolinska Institutet, Department of Clinical Neuroscience, Stockholm, SWEDEN PURPOSE Fertility in men with hypospadias may be impaired due to anatomical, surgical or etiological fac- tors and associated conditions. Fertility is further influenced by sociocultural and genetic factors, often shared within families. Only a few previous studies have investigated birthrates in men with hypospadias. The aim of this study was to evaluate fertility in men born with hypospadias by register-based data. MATERIAL AND METHODS Population-based cohort of 1.2 million men born in Sweden between 1964 and 1998, identified through national demographic and healthcare registers. Each individual was followed from 15 years of age to first outcome event, emigration, death, or 31 December 2013. Associations between being born with hypospadias and 1) being the biological father of children, 2) conceiving through assisted reproductive technologies and 3) receiving a diagnosis of male infertility, were investigated in the whole cohort with Cox proportional hazard models, expressed as hazard ratios (HRs) with 95 % confidence intervals (CIs). A stratified proportional hazard model, conditional on sibling group, was used to estimate the effects of shared familial confounding. Additional sensitivity analyses on the effect of associated malformations, cryptorchidism and psychiatric illness were conducted. RESULTS Men with hypospadias, as an aggregate, had a lower probability of having biological children (ad- justed HR 0.87, 95 % CI 0.83 to 0.92). A significant association was present in both distal (adjusted HR 0.90, 95 % CI 0.85 to 0.96) and proximal hypospadias (HR 0.59, 95 % CI 0.42 to 0.81). Point estimates remained similar, however non-significant, in sibling comparison. Further, men with either distal or proximal hypospadias demonstrated an increased probability of conceiving through ART, regardless of concomitant cryptorchidism. Men with proximal hypospadias were at increased risk of having a registered diagnosis of male infertility. CONCLUSIONS The results of this study suggest that fertility in men with both distal and proximal hypospadias is impaired, and the analysis in brothers implies that this is not due to shared familial factors. 11:51–11:57 Discussion