Endometrial thickness and pregnancy outcome after intrauterine insemination

To investigate whether endometrial thickness on the day of hCG administration is a predictor of intrauterine insemination (IUI) success.

A retrospective study.

Two hundred forty-nine women undergoing IUI cycles.

University hospital-based infertility center.

Endometrial thickness on the day of hCG administration, cycle parameters, and sperm quality were compared between pregnant and nonpregnant patients. A similar comparison was made between ongoing pregnancies and those that resulted in a loss.

Endometrial thickness versus IUI outcome.

The overall pregnancy rate was 15%. Mean (+/- standard deviation) endometrial thickness on the day of hCG administration was significantly greater in cycles where pregnancy was achieved (10.1 +/- 3.0 vs. 7.7 +/- 3.5). In the univariate analysis, the following variables affected the pregnancy rate: the woman's age, duration of infertility, the number of IUI cycles, the number of follicles, the diameter of the dominant follicle, the duration of follicle maturation, and sperm count, motility, and morphology. In the multivariate analysis, the strongest predictor of IUI success was the number of IUI cycles. The woman's age was negatively associated with pregnancy outcome, while endometrial thickness and the total motile sperm count were positively associated with pregnancy outcome.

The results of the present study suggest that clinicians providing IUI for infertile couples must pay close attention to endometrial development as well as to follicle growth and sperm motility.