Effects of indomethacin on follicular structure, vascularity, and function over the periovulatory period in women

Objective: To assess the effect of indomethacin (taken at defined times) on follicular rupture, indexes of intrafollicular blood flow, and steroidogenesis. Participants: Six healthy volunteers awaiting treatment for infertility by IVF-ET during subsequent natural cycles. Interventions: All women were examined (at least every 8 hours) by transvaginal ultrasonography with color Doppler imaging and had samples of blood taken for hormone analysis. A self-test for urinary LH was performed before each scan. Indomethacin was first taken (50 mg three times per day) according to the maximum follicular diameter (first four women) or when the LH dipstick gave a positive result; the drug was taken for greater than or equal to 3 days. Results: Follicular rupture was delayed in five of six cases (by 2 to 12 days). There was a reduction in intrafollicular peak systolic velocity before and after the positive urinary LH test compared with historical controls. Three follicles (50% of women) with the highest peak systolic velocity had an hemorrhagic appearance and persisted longer. There was no significant effect on menstrual cycle length or the levels of circulating FSH, E(2), LH, or P. Conclusion: Indomethacin administered at the time of a positive self-test for urinary LH can delay follicular rupture with an associated reduction in intrafollicular blood flow but with no apparent effects on hormonal or menstrual status.