Primary infertility and uterine anomalies.

During a 20-year period, 19 (9.1%) of 208 patients with uterine anomalies had primary infertility. Women with unicornuate uteri had the highest (15%) incidence of primary infertility, which was found in the other groups of uterine anomalies in 7% to 13% of the patients. The cause of infertility was a nonuterine factor in 12 cases: hormonal (8), endometriosis (2), tubal (1), or male (1). The reason for infertility remained unknown or the patient conceived during investigation in five cases. Malformation of the uterus was considered the sole reason for infertility, and metroplasty was performed in two cases. During the follow-up period, 14 patients (74%) achieved pregnancy: 6 spontaneously, 3 after curettage, 2 after metroplasty, 1 after clomiphene treatment, 1 after hysterosalpingogram, and 1 after conservative endometriosis surgery. Four of five cases without pregnancy had a nonuterine factor as the cause of infertility, and in one case it may have been a uterine anomaly--a unicornuate uterus with a rudimentary horn. The results indicate that uterine anomalies are rarely the reason for infertility. Nonuterine causes of infertility must be ruled out before metroplasty is performed, as a last resort.