Pilot study evaluating a progesterone vaginal ring for luteal-phase replacement in donor oocyte recipients

To evaluate the proportions of women demonstrating adequate endometrial transformation during a mock cycle and the 8-week clinical pregnancy rate in a donor oocyte cycle using a P vaginal ring or P vaginal gel.

Prospective, controlled, randomized trial.

Donor egg program at an academic center.

Women who are candidates for donor oocytes.

Subjects were analyzed for adequate endometrial transformation after suppression and pretreatment with E(2). Subjects were treated with 18 days of E(2) coupled with a weekly P vaginal ring or 90 mg 8% vaginal gel twice daily. Endometrial biopsies were performed on cycle day 25 or 26. Nine subjects successfully completing the mock cycle participated in an ET cycle using the same randomly assigned study medication.

Adequate endometrial transformation, pregnancy, safety, and tolerability of the vaginal ring.

Twenty women randomized 1:1 to either the P vaginal ring or vaginal gel completed the mock cycle. Endometrial histology was "in phase" for 8 of 10 (80%) in the vaginal ring group and 10 of 10 (100%) in the gel group. For the women who participated in the ET cycle, clinical pregnancies and live births were observed in 4 of 5 (80%) in the vaginal ring group and 1 of 4 (25%) in the vaginal gel group.

In women requiring luteal-phase replacement, the P vaginal ring was able to adequately transform the endometrium and was comparable to the P vaginal gel in efficacy and safety, while offering the advantage of weekly rather than multiple daily doses.