[Disorders of sex differentiation caused by exogenous hormones]

Transplacental and lactogenic exposure of fetus and neonate to exogenous hormones and endocrine disrupters can cause a range of abnormalities of the reproductive system including sex differentiation and sex maturation. Sex differentiation is critically dependent on the normal action of androgens and can be disturbed by unbalanced androgen/estrogen ratios. Androgenic substances masculinize female fetus. Progestogens act both as androgen antagonists, demasculinizing males, and as androgen agonists, masculinizing females. Transplacental exposure of male fetus to synthetic estrogen diethylstilbestrol is recognized to have led to increases in the incidence of cryptorchidism, hypospadia and decreased sperm counts. A growing number of endocrine disrupters have been found to possess either weak estrogenic, anti-androgenic or other hormonal activities. Increased exposure to environmental endocrine disrupters can cause male pseudohermaphroditism.