Mild stimulation protocol vs conventional controlled ovarian stimulation protocol in poor ovarian response patients: a prospective randomized controlled trial.

PURPOSE: To compare the efficacy of mild ovarian stimulation protocol and conventional controlled ovarian stimulation (COS) protocol for poor ovarian response (POR) patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). METHODS: This single-center prospective randomized controlled trial conducted from September 2013 to September 2015, including 191 patients who met the Bologna criteria of POR. Ninety-seven patients allocated to the mild ovarian stimulation group (MS group) were stimulated according to the letrozole/antagonist protocol, while 94 patients in the controlled ovarian stimulation group (COS group) were stimulated according to a high dose of gonadotropin (Gn) combined with gonadotropin-releasing hormone agonist (GnRH-a) stop protocol. The cumulative live birth rate was the primary outcome. Chinese clinical trial number ChiCTR-TRC-13003454. RESULTS: Comparing with the COS group, both the stimulation duration and the total gonadotropin dose were significantly shorter and lower in the MS group (P < 0.001). A higher number of retrieved oocytes (P = 0.003) and transferrable embryos (P = 0.029) were obtained in the COS group. The cumulative live birth rates (OR 1.103; 95% CI 0.53 to 2.28; P = 0.791) were comparable between the two groups. CONCLUSIONS: The increase of Gn dose during ovulation stimulation was associated with a higher number of transferrable embryos for POR patients, but this increase did not lead to a concomitant improvement of reproductive outcome, especially in terms of the cumulative live birth rate. Using a mild stimulation protocol was economically preferential while it was as effective as higher doses of Gn stimulation protocol in reproductive outcome for POR patients.