Lack of evidence for inhibition of ovulation by aspirin in women.

Prostaglandin synthetase inhibitors such as aspirin and indomethacin inhibit ovulation in experimental animals. The effect of therapeutic doses of aspirin on ovulation has been studied in 5 women. Ovulation, as assessed by measurements of urinary LH and plasma progesterone levels, basal body temperature and cervical mucus changes occured in all the control and treatment cycles. Serial sections of the corpora lutea failed to show any entrapped ova. The significance of finding a prostaglandin synthetase inhibitor which acts specifically at the ovarian level is discussed.