[Controlled ovarian stimulation and intrauterine insemination: an actual therapy?].

Purpose: To evaluate the pregnancy rate in intrauterine insemination (IUI), and to determine possible prognostic factors of successful pregnancy.

Methods: A retrospective study of IUI cycles performed in the Reproductive Medicine Unit of Vila Nova de Gaia Hospital, between January 2007 and July 2010. The IUI cycles were preceded by ovarian stimulation and monitored by vaginal ultrasound. Clinical pregnancy rates were analyzed according to the woman's age, type and duration of infertility, spermatozoa parameters assessed in the spermogram, number of mature follicles and the drug used for ovarian stimulation. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS17), with the level of significance set at p<0.05.

Results: The study comprised 139 couples who underwent 220 IUI cycles. The absolute pregnancy rate per cycle was 18.6%. Of the 41 clinical pregnancies, 5 were twin pregnancies (12.1%). The pregnancy rate was higher at ages <30 years (28.5 vs 15.7%; p=0.024), duration of infertility <3 years (23.8 vs 13.9%; p=0.05), normal sperm motility (23.2 vs 10.3%; p=0.01) and with two follicles at the time of insemination (27.7 vs 14.2% for monofollicular growth; p=0.030). The pregnancy rates obtained with clomiphene citrate, gonadotropins and combined clomiphene citrate/gonadotropin were 13.0, 26.1 and 28.6%, respectively, with a statistically significant difference in clinical pregnancy rate between clomiphene citrate and gonadotropin.

Conclusions: IUI remains a natural starting point for conveniently selected couples with infertility. Younger age and normal sperm motility are good prognostic factors. Gonadotrophin stimulation seems to be an important tool for improving the pregnancy rate of IUI.