目的:系统评价不同剂量的来曲唑(LE)对多囊卵巢综合征(PCOS)患者的疗效,为临床用药提供一定的依据。方法:计算机检索中国知网、维普、万方、Pubmed、The Cochrane Library、Science Direct等数据库,提取出相关的随机对照试验,对各文献进行质量评价后,采用Rev Man5.3软件分析患者的促排卵结局和妊娠结局。结果:1共有9篇文献纳入本研究中,包含816例PCOS患者,共计816个周期;2 Meta分析显示2.5 mg LE与5.0 mg LE在排卵率、流产率、不良事件(多胎妊娠和卵巢过度刺激综合征)发生率及h CG注射日子宫内膜厚度之间的差异均无统计学意义(P>0.05),而5.0 mg组的妊娠率高于2.5 mg组,差异具有统计学意义(RR=0.58,P=0.001);5.0 mg组与7.5 mg组在排卵率、周期妊娠率、不良事件发生率、h CG注射日子宫内膜厚度之间的差异均无统计学意义(P>0.05)。结论:在临床上对有生育要求的PCOS患者可使用LE促排卵时,5.0 mg剂量有着更高的妊娠率,值得在临床上推广使用。对于效果不佳者,进一步提高剂量并未显示有提高疗效的作用。 OBJECTIVE: To systematically evaluate the efficacy of different doses of letrozole (LE) in patients with polycystic ovary syndrome (PCOS) and provide some evidences for clinical use. Methods: The databases of CNKI, VIP, Wanfang, Pubmed, The Cochrane Library, Science Direct and so on were searched by computer, and related randomized controlled trials were extracted. After evaluating the quality of each literature, RevMan5.3 software was used to analyze the patients’ Ovulation outcomes and pregnancy outcomes. RESULTS: 1 A total of 9 articles were included in this study, including 816 PCOS patients for a total of 816 cycles. Meta-analysis showed that there was significant difference in ovulation rate, miscarriage rate, adverse events (multiple pregnancy and ovarian hyperstimulation (P> 0.05), while the pregnancy rate in 5.0 mg group was higher than that in 2.5 mg group (P <0.05), the difference was statistically significant (RR = 0.58, P = 0.001). There was no significant difference between the 5.0 mg group and the 7.5 mg group in ovulation rate, pregnancy rate, incidence of adverse events and endometrial thickness on h CG injection day (P> 0.05). CONCLUSION: In the clinical use of ovulation-promoting ovulation in women with PCOS requiring fertility, the 5.0 mg dose has a higher pregnancy rate and is worth popularizing in clinic. For poor effect, to further enhance the dose did not show the effect of improving the efficacy.