Developmental exposure to endocrine disruptors and male urogenital tract malformations

Abstract

Discrepancies in adverse trends in male reproductive health around the world are due in part to the difficulty of comparing studies from different time periods with distinct study populations and varied clinical definitions and diagnostic criteria for these processes. In this context, the apparent increase in the incidence of cryptorchidism and hypospadias in the Western world over recent decades, with a leveling offin hypospadias incidence in most European countries during the 1980s, can be questioned due to differences in case definitions, age at diagnosis, examination techniques, and study populations, e.g., registry versus cohort studies. Experimental investigations have supported the hypothesis of a link between environmental factors and urogenital tract malformations, suggesting that cryptorchidism and hypospadias are associated with exposure to environmental chemicals, especially those identified as endocrine-disrupting chemicals (EDCs). Exposure to EDCs during pregnancy may play a role in the development of male sexual disorders because sexual differentiation and reproductive functioning are critically dependent on the ratio of androgens to estrogens, and an imbalance in this ratio may be responsible for male congenital anomalies. Epidemiology studies have also indicated a link between EDCs and malformations. The accumulated evidence appears sufficient to endorse a precautionary approach, with the implementation of measures to reduce community exposure to EDCs, especially in women of childbearing age, both before and during pregnancy.