Abstract

PIP: During 1975-1977, 20 women undergoing mid-trimester (mean 16.1 weeks) abortions induced by Rivanol were treated with oral doses of 50 mg indomethacin every 6 hours starting immediately prior to the instillation of Rivanol. A group of 55 women undergoing Rivanol abortions (mean gestational age 15.6 weeks) during the same period acted as a control. It was found that administration of indomethacin, a strong inhibitor of prostaglandin synthesis, prolonged the induction-abortion interval significantly from a mean of 32.3 hours in the control group to a mean of 46.9 hours in the indomethacin group. This result adds support to the theory that the mechanism by which Rivanol induces abortion involves the stimulation of the endogenous production of prostaglandins.