The reproductive system is extremely susceptible to insults from exposure to exogenous
steroids during development. Excess prenatal
testosterone exposure programs neuroendocrine, ovarian, and metabolic deficits in the female, features seen in women with polycystic ovary disease. The objective of this study was to determine whether prenatal
testosterone excess also disrupts the male reproductive system, using sheep as a model system. The extent of reproductive disruption was tested by assessing sperm quantity and quality as well as Leydig cell responsiveness to
human chorionic gonadotropin. Males born to mothers treated with 30 mg
testosterone propionate twice weekly from d 30 to 90 and with 40 mg
testosterone propionate from d 90 to 120 of pregnancy (T-males) showed a significant reduction (P < 0.05) in
body weight, scrotal circumference, and sperm count compared with control males. Mean straight line velocity of sperms was also lower in T-males (P < 0.05). Circulating
testosterone levels in response to the
human chorionic gonadotropin did not differ between groups. These findings demonstrate that exposure to excess
testosterone during fetal development has a negative impact on reproductive health of the male offspring, raising concerns relative to unintended human exposure to steroidal mimics in the environment.