Archives of Gynecology and Obstetrics

, Volume 289, Issue 3, pp 687–693

Letrozole ovulation induction: an effective option in endometrial preparation for frozen–thawed embryo transfer

  • Song-jun Li
  • Yong-jing Zhang
  • Xiao-shan Chai
  • Mei-fang Nie
  • Yu-yan Zhou
  • Jian-lin Chen
  • Guang-shi Tao
Gynecologic Endocrinology and Reproductive Medicine

DOI: 10.1007/s00404-013-3044-0

Cite this article as:
Li, S., Zhang, Y., Chai, X. et al. Arch Gynecol Obstet (2014) 289: 687. doi:10.1007/s00404-013-3044-0

Abstract

Purpose

To evaluate the clinical efficacy of letrozole on ovulation induction and hormone replacement therapy (HRT) during endometrial preparation for frozen–thawed embryo transfer (FET).

Methods

We analyzed totally 1,230 cycles of patients that underwent FET from October 2010 to September 2012. Seven hundred and thirteen cycles of patients with ovulation disorders that underwent FET were randomly assigned to two groups by case control study. 359 cycles received letrozole ovulation induction and 354 cycles received HRT during endometrial preparation for FET, respectively. In the corresponding period, 517 cycles of patients with normal ovulation in the natural cycle group for FET endometrial preparation served as controls. Reproduction-related clinical outcomes of patients in the three groups were compared.

Results

The embryo implantation rate of patients in letrozole group (30.4 %) was significantly higher than the HRT group (22.8 %, P < 0.05). The clinical pregnancy rate of patients in the letrozole group (53.2 %) was significantly higher than the HRT group (44.4 %, P < 0.05), while no significant difference was observed between the letrozole and natural cycle groups (51.3 %, P > 0.05). Estradiol levels on the day of human chorionic gonadotropin administration in the letrozole group were significantly lower than those in the natural cycle group (280.32 ± 125.39 pg/ml and 351.06 ± 123.03 pg/ml, respectively; P < 0.05). The live birth rate of patients in letrozole group (44.6 %) was significantly higher than the HRT group (32.5 %, P < 0.05), while abortion rate (12.0 %) was significantly lower than the HRT group (21.0 %, P < 0.05). There were no significant differences in number of mature follicles, endometrial thickness, duration of follicle growth between the letrozole and the natural cycle groups, and there were no significant differences in twin birth rate and ectopic pregnancy rate among the three groups (all P values >0.05).

Conclusions

Ovulation induction with letrozole during endometrial preparation for FET has a higher rate of pregnancy success and a lower abortion rate than HRT. Letrozole treatment exhibits clinical progression and outcomes similar to those patients undergoing a natural cycle or normal ovulation cycle. Therefore, letrozole treatment may be an effective option in endometrial preparation for FET in patients with ovulation disorders or irregular menstruation.

Keywords

LetrozoleFrozen–thawed embryo transferOvulation inductionEndometrial preparationClinical efficacy

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Song-jun Li
    • 1
    • 2
  • Yong-jing Zhang
    • 1
  • Xiao-shan Chai
    • 1
  • Mei-fang Nie
    • 1
  • Yu-yan Zhou
    • 2
  • Jian-lin Chen
    • 1
  • Guang-shi Tao
    • 1
  1. 1.Department of Obstetrics and Gynaecology, The Second Xiangya HospitalCentral South UniversityChangshaChina
  2. 2.Department of Reproductive Medicine CentreArmed Police Corps Hospital of Guang Dong BorderShenzhenChina