Ovarian stimulation in infertile women treated with intrauterine insemination: a cohort study from China

In couples with unexplained and mild male-factor infertility, intrauterine insemination with the use of letrozole may increase live birth rates compared with natural cycles, without increasing multiple pregnancy rates.

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Volume 109, Issue 5, Pages 872–878


Shuo Huang, Ph.D., M.D., Rui Wang, M.D., Rong Li, Ph.D., M.D., Haiyan Wang, Ph.D., M.D., Jie Qiao, Ph.D., M.D., Ben Willem J. Mol, Ph.D., M.D.



To study the effectiveness of different ovarian stimulation protocols compared with natural cycle treatment in an intrauterine insemination (IUI) program.


Retrospective cohort study.


Large reproductive medicine center.


Couples with unexplained or mild male-factor infertility.


Couples were treated with the use of natural-cycle IUI, or IUI after ovarian stimulation with the use of clomiphene citrate (CC), letrozole, or gonadotropins.

Main Outcome Measure(s)

Live birth, multiple pregnancy rates, and cumulative live birth rates after three IUI cycles.


We performed 14,519 IUI cycles in 8,583 couples. Compared with natural-cycle IUI (6.2%), live birth rates were significantly higher in IUI cycles stimulated with the use of CC (8.9%), letrozole (9.4%) and gonadotropins (9.5%). The multiple pregnancy rate resulting from natural cycles was 0.7%, compared with 4.6% in CC cycles, 1.3% in letrozole cycles, and 4.2% in gonadotropin cycles. Cumulative live birth rates after three IUI cycles were 18.4% after natural-cycle IUI, and 25.7%, 26.2%, and 23.7% with the use of CC, letrozole, and gonadotropins, respectively.


In an IUI program for unexplained or mild male-factor infertility, ovarian stimulation with letrozole may significantly increase live birth rates while controlling multiple pregnancy rates.

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Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders.