Article Abstract

Effects of letrozole combined with human menopausal gonadotrophin in ovarian stimulation for intrauterine insemination cycles

Authors: Xiaoying Yu, Zhiwen Cao, Wenwen Hou, Weihua Hu, Guijun Yan


Background: The effects of letrozole plus human menopausal gonadotropin (HMG) on ovarian stimulation (OS) of intrauterine insemination (IUI) cycles were examined.
Methods: In all, 1,005 IUI cycles were included in this study. Couples underwent natural cycle (NC) IUI (n=150) or IUI after OS with letrozole (n=207) or IUI after OS with letrozole + HMG (n=648).
Results: The clinical pregnancy rates were 9.0%, 13.0%, and 17.0%, and the live birth rates were 7.0%, 9.0%, and 14.0% in the NC, letrozole, and letrozole + HMG IUI groups, respectively. The twin pregnancy rate of the letrozole + HMG group (11.0%) was higher than that of the NC (7.0%) and letrozole groups (4.0%). To date, the only triplet pregnancies to occur were in the letrozole + HMG group. On the day of human chorionic gonadotropin (hCG), the number of follicles with an average follicle diameter greater than 18 mm in the letrozole + HMG group (1.21±0.56) and letrozole group (1.14±0.48) was greater than that in the NC group (0.85±0.36). The thickness of the endometrium in the letrozole + HMG group (8.8±2.1 mm) was significantly greater than that in the letrozole group (7.3±1.6 mm).
Conclusions: The letrozole + HMG protocol of OS in IUI can improve follicular development, increase the thickness of endometrium, significantly increase the live birth rate, but not significantly increase the multiple pregnancy rate.