Objective To compare the pregnancy outcomes of first frozen-thawed embryo transfer in women undergoing IVF using progestin primed ovarian stimulation (PPOS) versus GnRH antagonist protocol. Design Retrospective cohort study. Setting Tertiary-care academic medical center. Population/Sample 382 infertile women with normal ovarian reserve underwent IVF. Methods Women were allocated to PPOS group (n=184) or GnRH antagonist group (n=198) at the discretion of the attending physicians. Main outcome measures The primary outcome was the ongoing pregnancy rate of first FET cycles. Results Both groups had almost comparable demographic and cycle stimulation characteristics. The ongoing pregnancy (34.0 % (49/114) vs 42.3% (52/123), P=0.166, RR=0.81(0.59-1.09)), clinical pregnancy (38.2% (55/144) vs 44.7% (55/123), P=0.281, RR=0.85 (0.64-1.14)) and implantation (29.5% (75/254) vs 31.6% (68/215), P=0.623, RR=0.93 (0.71-1.22)) rates were comparable between the PPOS group and the antagonist group respectively. In order to control the difference in demographic and index stimulated IVF cycle characteristics, a multivariate logistic regression revealed that only the stimulation protocol and number of embryos replaced were significant factors in predicting the ongoing pregnancy. Conclusion The use of medroxyprogesterone during ovarian stimulation is effective in blocking the LH surge, and does not affect the number of oocytes collected in the woman with normal ovarian reserve. However，developmental potential of embryos originating from this regimen seems to be affected compared to those from the antagonist group.