Abstract: Objective：To evaluate the follicular output rate (FORT) as a prognostic indicator of response to ovarian and the reproductive competence after PGD. Methods: A total of 158 PGD patients who underwent controlled ovarian stimulation using a long protocol were retrospectively studied. FORT was calculated as the ratio of preovulatory follicle count on the day of stimulation×100/small antral follicle count (3-10 mm in diameter) at baseline. Patients were divided into 2 groups：the low FORT group（79 women） and the high FORT group (79 women）. The response of ovarian and IVF-ET pregnancy outcome were analyzed. Results: Among 158 PGD cycles, the numbers of retrieved oocytes and embryos available for transfer in the high FORT group were significantly higher than those in the low FORT group (P＜0.05). However, there were no significant differences in the 2PN fertility rate, good-quality embryos rate and blastocyst formation rate between two groups (P＞0.05). Conclusions: FORT can be used as a index to predict effectively the number of oocytes retrieved and the number of embryos for transfer in the PGD cycle, but it cannot predict the developmental potential of the embryo.

Key words: Preimplantation diagnosis, Reproductive techniques, assisted;, Follicular output rate, Ovary, Ovarian follicle, Pregnancy outcome