Effects of prenatal maternal estrogen on the male urogenital system.

Effects of in utero exposure to estrogens on the testis and prostate were assessed in male perinates. Exposure to diethylstilbestrol alone or combined with other female sex hormones correlated with hypertrophy and squamous metaplasia of the prostatic utricle and ducts, and with high ratios of Leydig cells to spermatogenic cells in the testis. These changes were not correlated with maternal diabetes, other congenital abnormalities, exposure to progestogens and steroidal estrogens, or thyroid hormones. Within the affected group an interaction was found between the hormones administered and the trimester during which treatment was started. These findings suggest that exogenous female sex hormones may interfere with the action of müllerian inhibiting factor in the human male fetus. The prostatic ducts also respond to maternal estrogen treatment. Relevance to later health is unknown.