The fertility problems of 176 patients with uterine malformations [arcuate (n = 40), bicornuate (n = 49), bicornis-bicollis (n = 17), didelphys (n = 15), unicornuate (n = 24), subseptus (n = 14) and septate uterus (n = 17)] and of 28 women with other genital and/or urinary anomalies but with a normal uterus were studied. Ten patients with a uterine anomaly experienced infertility without other causes (6%). 142 women with uterine malformations and 26 with a normal uterus achieved pregnancy, the total number of pregnancies to date being 383 and 47 in these groups respectively. The outcome of the first pregnancy from women with uterine malformations was similar to that of all pregnancies though less significant. Only 53% of pregnancies in women with uterine malformations ended with a child surviving > 7 days, compared to 89% in women with a normal uterus. The poorest viability results were found in the bicornuate (40%) (47% of pregnancies in this group ended in early abortions), arcuate (45%) and septate uterus groups (59%). The rates of children surviving > 7 days were around 70% in the bicornis-bicollis, didelphys, unicornuate and subseptus uterus groups. Metroplasty in four cases corrected the infertility or repeated abortions in three patients. Cerclages (21) in 14 women increased the live birth rate from 21 to 62%. These results confirm earlier reports that patients with uterine malformations have higher rates of reproductive loss, preterm delivery, breech presentation and complications that increase obstetric intervention and perinatal mortality. Moreover in our study, pregnancy outcome was poorer in the bicornuate and arcuate uterus groups than in the septate group. Metroplasty does not seem justified except in specific cases. Cerclage may be indicated in the majority of cases, especially in those with bicornuate and septate uterus, in cases of diminished fertility and before considering surgical metroplasty.