Prolonged inhibition of placental and ovarian 3β-hydroxysteroid dehydrogenase during pregnancy and the luteal phase of the menstrual cycle

SummaryThe effects of a competitive inhibitor of 3β-hydroxysteroid dehydrogenase (3β-HSD), Epostane (Sterling Winthrop) on serum progesterone, oestradiol and Cortisol have been studied in twenty women who were awaiting termination of pregnancy and thirteen women in the luteal phase (days 19-21) of their menstrual cycle. In the pregnant women there was a highly significant decline in the mean serum progesterone concentration to 13-Onmol/litre (19 percent of the pretreatment value) after 4 days of treatment. A similar fall in serum oestradiol was observed. Progressive uterine activity did not occur in association with these changes. In the luteal phase study there was also a significant decline in serum progesterone to 13 per cent of the pretreatment value and this was accompanied by uterine bleeding, in 6 of 8 patients. The mean serum oestradiol concentration did not change. This treatment did not produce any adverse side effects and the mean serum Cortisol concentrations in both studies did not differ fro...