Interruption of first trimester human pregnancy following Epostane therapy. Effect of prostaglandin E2 pessaries

Summary. The effect of Epostane, a competitive inhibitor of the 3β hydroxy steroid dehydrogenase enzyme system in combination with prostaglandin E₂ (PGE₂) for induction of abortion in early first trimester pregnancy has been studied in a group of 20 women awaiting termination of pregnancy. The women were consecutively assigned to four treatment groups. The first group was treated with PGE₂ alone, administered vaginally as a lipid based (Witepsol) pessary. The remaining three groups received Epostane at differing doses for 5 days, and were treated with PGE₂ on the fourth day. Significant falls in serum progesterone and oestradiol occurred in the Epostane-treated patients. Abortion was induced in one of the five control patients and in three of 10 patients treated with low doses (300–400 mg) of Epostane. Intra-utrine pressure monitoring showed an increased reactivity to PGE₂ in the treated groups. At the highest dose (600 mig) of Epostane, serum progesterone and oestradiol showed the greatest decline to 8% and 21% of the pretreatment values, a prompt and sustained pressure response occurred to PGE₂ and abortion was induced in all five patients. A critical degree of progesterone suppression appears to sensitize the myometrium to exogenous prostaglandin. This combined treatment is an effective method of early pregnancy termination and may have a role in the management of mid-trimester abortion.