The effects of letrozole on women with endometriosis undergoing ovarian stimulation for in vitro fertilization

Abstract

This study aimed to analyze the effects of a new protocol with letrozole on the outcomes of in vitro fertilization (IVF) cycles in women with endometriosis. This retrospective cohort study was conducted for women diagnosed with endometriosis undergoing IVF from an infertility clinic. A new protocol, combination therapy with letrozole and gonadotropin, was used from August 2016 to January 2018 (‘protocol 1’, n = 38). From March 2014 to July 2016, conventional IVF with gonadotropin was administered (‘protocol 2’, n = 26). Age and ovarian reserve were comparable between the two groups. The patients who received protocol 1 resulted in a significantly lower peak estradiol level in IVF compared with those received protocol 2 (722 ± 1076 pg/mL versus 2168 ± 1521 pg/mL, p < .001). The length of stimulation, the total dose of gonadotropin, number of oocytes retrieved, fertilization rates, and number of embryos obtained were similar between the two groups. The mean percentage of mature oocytes was lower (69.9 ± 23.7% versus 80.2 ± 21.0%, p = .029) in patients with protocol 1. While maintaining low estrogen levels, the combination therapy with letrozole and gonadotropin produce similar oocyte and embryo yield to the conventional IVF protocol in women with endometriosis.

摘要

这项研究旨在分析使用来曲唑的新方案对子宫内膜异位症妇女体外受精（IVF）周期结果的影响。这项回顾性队列研究是针对从不育诊所诊断为子宫内膜异位症并接受IVF的女性进行的。从2016年8月至2018年1月, 采用了一种新方案, 即来曲唑和促性腺激素联合治疗（“方案1”, n = 38）；从2014年3月到2016年7月, 用促性腺激素进行常规IVF治疗（“方案2”, n = 26）。两组之间的年龄和卵巢储备相似。与接受方案2的患者相比, 接受方案1的患者的IVF雌二醇峰值水平显着降低（722±1076 pg/mL对2168±1521 pg/mL, p <0.001）。两组的刺激时间、促性腺激素的总剂量、回收的卵母细胞数量、受精率和获得的胚胎数量相似。方案1患者的成熟卵母细胞平均百分比较低（69.9±23.7％对80.2±21.0％, p = 0.029）。在维持低雌激素水平的同时, 来曲唑和促性腺激素的联合治疗可使子宫内膜异位症患者的卵母细胞和胚胎产量与常规IVF方案相似。

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:

• In vitro fertilization
• letrozole
• aromatase inhibitors
• endometriosis
• estradiol

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the SNUBH Research Fund (Grant No. 00–2018-023).