Progesterone for Luteal Phase Support in In Vitro Fertilization: Comparison of Vaginal and Rectal Pessaries to Vaginal Capsules: A Randomized Controlled Study

BACKGROUND In IVF, Luteal phase support is usually performed using vaginal progesterone. A part of patients using this route reports being uncomfortable with this route. We tried to study whether the rectal route could be an effective alternative and associated with less discomfort. PATIENTS AND METHODS A prospective randomized controlled study. All patient were eligible for IVF treatment for infertility. After oocyte pickup, 186 patients were allocated to one the following protocols for luteal phase support: (i) rectal pessaries group: natural progesterone pessaries administered rectally 200 mg three times a day, (ii) vaginal pessaries group: natural progesterone pessaries administered vaginally 200 mg three times a day), and (iii) vaginal capsules group: natural micronized progesterone capsules administered vaginally 200 mg three times a day. On the day of pregnancy test, patients were asked to fill in a questionnaire conducted by an investigator in order to assess the tolerability and side effects of the LPS treatment taken. The primary endpoint was the occurrence of perineal irritation. RESULTS Fifty eight patients were assigned to the rectal pessaries group, 68 patients to the vaginal pessaries group, and 60 patients to the vaginal capsules group. All patients adhered to their allocated treatment. Implantation and clinical pregnancy rates per transfer did not differ between the three groups. Perineal irritation, which was our primary endpoint, was the same for all the three groups (respectively 1.7 % versus 5.9 % versus 11.7%). Regarding the other side effects, more patients experienced constipation and flatulence with the rectal route, whereas more patients reported vaginal discharge in the vaginal capsules group. CONCLUSION Rectal administration for luteal phase support is effective and well accepted alternative to vaginal route.