Inhibition of fetal growth and survival by testosterone administration to pregnant sheep

Abstract

Testosterone (as testosterone enanthate, 250 mg i.m. every 2 wk) was administered to pregnant ewes (n = 16), and injections of vehicle were used in 10 control pregnant ewes between days 75 of gestation and term (day 147). Fetal survival (7 of 16 in the treated group versus 10 of 10 in the controls) and growth (birth weights 4.00 +- 0.51 kg in the treated group versus 5.79 +- 0.93, mean +- SD, in the controls) were markedly impaired by testosterone administration. The mechanism of the testosterone effect is unknown, but could be through metabolism to estrogens by the feto-placental unit. These results imply that alterations in the production or metabolism of androgens by the mother or the feto-placement unit may exert important effects on fetal growth and survival.