Hypospadias is a male birth defect in which the urethral orifice is abnormally located on the ventral side of the penis. In western countries, the prevalence of hypospadias varies from 2 to 8 cases per 1000 live births.
An increase in the prevalence of hypospadias has been reported, but the environmental causes remain virtually unknown. The objectives of the project were to assess the association between risk of hypospadias and indicators of placental function and endogenous hormone levels, exposure to exogenous hormones, maternal diet during pregnancy, and other environmental factors.
A case-control study was conducted in Sweden and Denmark from 2000 through 2005 using self-administered questionnaires completed by mothers of hypospadias cases and matched controls. The response rate was 88% and 81% among mothers of cases and controls, respectively. The analyses included 292 cases and 427 controls.
In the study, a diet during pregnancy lacking both fish and meat was associated with more than a four-fold
increased risk of hypospadias. Boys born to obese (BMI â‰¥ 30) women had a more than two-fold increase in risk of hypospadias compared with boys born to mothers with a normal weight (BMI 20-24). Maternal hypertension
during pregnancy and absence of maternal nausea increased a boy’s risk of hypospadias 2.0-fold and 1.8-fold, respectively. By contrast, nausea in late pregnancy appeared to be positively associated with hypospadias risk.
O Akre, HA Boyd, M Ahlgren, K Wilbrand, T Westergaard, H Hjalgrim, A Nordenskjoeld, A Ekbom, M Melbye, Maternal and Gestational Risk Factors for Hypospadias, Environmental Health Perspectives 2008, 116, 1071-1076.