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.