The influence of aspirin on the course of induced midtrimester abortion

Prostaglandins appear to mediate the uterine contractions of abortion and labor, and aspirin has been shown to be an inhibitor of prostaglandin synthesis. In this double-blind, placebo-controlled, prospective, and randomized study, aspirin was administered orally in doses of 600 mg. every 6 hours to patients undergoing induced midtrimester abortions with hyperosmolar urea and oxytocin augmentation. The mean injection-abortion interval was significantly prolonged by aspirin in nulliparous patients (aspirin 32.3 +/- 3.3 hr. vs. placebo 21.5 +/- 3.5 hr.) and no aspirin-treated nullipara aborted in less than 18 hours. There was no significant difference between treatment groups in the mean injection-abortion interval in the multiparous patients at the dose of aspirin used. The effectiveness of aspirin in the prolongation of the injection-abortion interval has potential therapeutic implications for the treatment of premature labor.