Objective: To evaluate whether acupuncture pretreatment followed by letrozole leads to a higher live birth rate in PCOS when compared with letrozole alone. Design: Multicenter randomised controlled trial. Setting: Three hospitals in China. Population or Sample: Anovulatory women with PCOS aged from 20 to 40 years who had at least one patent tube. Methods: Participants were randomly assigned to receive acupuncture pretreatment followed by letrozole (pretreatment group) or letrozole alone (control group). Acupuncture pretreatment was given three times per week for 16 weeks, and letrozole was given five days per cycle for up to four cycles. Main outcome measures: The cumulative live birth rate (defined as a delivery after 20 weeks’ gestation). Results: The cumulative live birth rate was 41.1% (79/192) in the pretreatment group and 34.4% (66/192) in the control group with no significant difference between groups but was significantly higher in the pretreatment group (48/98, 49.0%) among those with baseline HOMA-IR <2.14, when compared with the control group (19/66, 28.8%). No significant differences were found between groups stratified by the letrozole cycle number, body mass index, age, PCOS phenotype, or hyperandrogenism. Conclusions: Acupuncture pretreatment followed by letrozole did not increase the cumulative live birth rate of anovulatory women with PCOS when compared with letrozole alone but may increase the cumulative live birth rate in those whose baseline HOMA-IR is <2.14. Key words: acupuncture, letrozole, live birth, PCOS, pretreatment

Background There is scarcity of information about the cumulative live birth rates(CLBRs) and time to live birth(TTLB) between progestin primed ovarian stimulation protocol(PPOS) and long GnRH agonist protocol. Objective To compare CLBRs and TTLB in women with normal ovarian reserve following PPOS with long GnRH agonist protocol. Methods A total of 995 women who underwent IVF using either PPOS (n=509) or GnRH antagonist (n=486) ovarian stimulation at the discretion of the attending physicians. The primary outcome measure was the CLBRs within 18 months from the day of ovarian stimulation. Results Both groups had almost comparable demographic and cycle stimulation characteristics except for duration of infertility which was shorter in the PPOS group. CLBRs after one complete IVF cycle including fresh and subsequent FET cycles within 18 months follow up were significantly lower in the PPOS group compared that in the long agonist group 206/509 (40.5%) and 307/486 (63.2%), respectively (odds ratio (OR): 0.641; 95% CI: 0.565-0.726). The average TTLB was significantly shorter in the long agonist group compared to the PPOS group (P < 0.01). In Kaplan-Meier analysis, the cumulative incidence of ongoing pregnancy leading to LB was significantly higher in the long agonist compared in the PPOS group (P < 0.001). Cox regression analysis revealed stimulation protocol adopted was strongly associated with the CLBRs after adjusting other confounding factors (OR =1.917 (1.152-3.190), P=0.012). Conclusion PPOS offers no advantage over conventional protocol in women with a normal ovarian reserve undergoing IVF. Keywords: PPOS, long GnRH agonist protocol, IVF, CLBRs, TTLB

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.