Background There remains considerable global unmet contraceptive need, with almost 200 million women reporting desire to limit or space childbearing without contraceptive use. Researchers have documented worldwide interest in an oral, on-demand contraceptive option were it available. Candidates for use include ulipristal acetate (UA), levonorgestrel and cyclo-oxygenase-2 (COX-2) inhibitors alone or in combination.

Methods We performed an exploratory, prospective study of matched menstrual cycles: one baseline cycle and one treatment cycle of UA 30 mg plus meloxicam 30 mg just prior to ovulation. The primary outcome was ovulation disruption, defined as unruptured dominant follicle for 5 days. Secondary outcomes included comparing cycle length, endometrial stripe thickness, and side effects.

Results Nine participants completed all study procedures in both cycles. Ovulatory disruption occurred in 66.7% (n=6) of treatment cycles and all but one demonstrated features of ovulatory dysfunction. Cycle length (mean±SD) was longer in the treatment cycle (31.9±4.0 vs 28.6±3.5 days, p<0.01). Secondary outcomes did not differ between the two cycles.

Conclusions UA plus the COX-2 inhibitor meloxicam disrupts ovulation at peak luteal surge and is a promising candidate for evaluation as a pericoital oral contraceptive.

Trial registration number NCT03354117.