Comparison of endometrial receptivity of clomiphene citrate versus letrozole in women with polycystic ovary syndrome: a randomized controlled study

Abstract

The aim of the study was to compare the effect of clomiphene citrate (CC) and letrozole on endometrial receptivity for ovulation induction in women with polycystic ovary syndrome (PCOS). A randomized controlled study included 160 patients diagnosed with PCOS, out of which 80 patients received 50 mg of CC and 80 patients received 2.5 mg of letrozole for successful ovulation induction. Endometrial thickness and pattern, the blood flow of uterine artery and subendometrial region, endometrial volume and vascularization index were measured. The ratio of multilayered endometrial pattern in letrozole group was significantly increased on the day of human chorionic gonadotropin (hCG) administration compared with CC group (77.5% vs. 55.0%). The volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of endometrium on the day of hCG administration and 7–9 days after ovulation in letrozole group were significantly increased. The biochemical pregnancy rate, clinical pregnancy rate, and ongoing pregnancy rate in letrozole group were significantly increased compared with CC group (36.3%, 30.0%, 22.5% vs. 21.3%, 13.8%, 10.0%, respectively). Letrozole increased pregnancy rates by improving endometrial receptivity compared with CC in patients with PCOS.

摘要

本研究的目的是比较克罗米芬(CC)和来曲唑(Letrozole) 诱导排卵对多囊卵巢综合征(PCOS)患者子宫内膜容受性的影响。一项随机对照研究包括160名确诊为PCOS的患者, 其中80名患者应用50 mg CC, 80名患者应用2.5 mg来曲唑成功诱导排卵, 测量这些患者的子宫内膜厚度和形态, 子宫动脉和子宫内膜下血流, 子宫内膜体积和血管化指数。在人绒毛膜促性腺激素(HCG)注射日, 来曲唑组子宫内膜多层模式的比例明显高于CC组(77.5%vs.55.0%)。来曲唑组在hCG给药当天和排卵后7∼9d子宫内膜体积、血管化指数(VI)、流量指数(FI)和血管化流量指数(VFI)均明显增加。来曲唑组的生化妊娠率、临床妊娠率和持续妊娠率均明显高于CC组(分别为36.3%, 30.0%, 22.5%比21.3%, 13.8%, 10.0%)。与CC相比, 来曲唑通过改善PCOS患者的子宫内膜容受性而增加妊娠率。

The Chinese abstracts are translated by Prof. Dr. Xiangyan Ruan and her team: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China.

Keywords:

• Polycystic ovary syndrome
• endometrial receptivity
• endometrial and subendometrial blood flows
• clomiphene citrate
• letrozole

Disclosure statement

No potential conflict of interest was reported by the authors.