Pregnancy termination with the PGE2-analogue SHB 286.

A group of 94 volunteers were treated with PGE2-analogue SHB 286 at the 12+1 week of pregnancy. Of the 94 gravidas, 78 received a single extravular dose of 50-200 microgram (Mean +/- S.E. 76 +/- 7 microgram) while 16 a short intravenous infusion of 1000-2000 microgram SHB 286. Despite the single treatment and low dose, the success rate was 69% and the instillation abortion time only 15 +/- 1 hours. At 24 hours after treatment even those gravidas who failed to abort (31%) had sufficient cervical dilatation for curettage and thus could be spared from rapid surgical dilatation. Peripheral plasma progesterone and estradiol-17 beta decreased significantly at 4 hours after treatment in those gravidas who subsequently aborted. After an initial contracture response of the uterus to SHB 286, the cyclic intraterine pressure evolved gradually. In 4 hours it reached significantly higher levels in those gravidas who subsequently aborted than in those who did not.