Clinical implications of uterine malformations and hysteroscopic treatment results.

Uterine malformations consist of a group of miscellaneous congenital anomalies of the female genital system. Their mean prevalence in the general population and in the population of fertile women is approximately 4.3%, in infertile patients approximately 3.5% and in patients with recurrent pregnancy losses approximately 13%. Septate uterus is the commonest uterine anomaly with a mean incidence of approximately 35% followed by bicornuate uterus (approximately 25%) and arcuate uterus (approximately 20%). It seems that malformed uterus and especially septate uterus is not an infertility factor in itself. However, it may have a part in the delayed natural conception of women with mainly secondary infertility. On the other hand, patients with uterine malformations seem to have an impaired pregnancy outcome even as early as their first pregnancy. Overall term delivery rates in patients with untreated uterine malformations are only approximately 50% and obstetric complications are more frequent. Unicornuate and didelphys uterus have term delivery rates of approximately 45%, and the pregnancy outcome of patients with untreated bicornuate and septate uterus is also poor with term delivery rates of only approximately 40%. Arcuate uterus is associated with a slightly better but still impaired pregnancy outcome with term delivery rates of approximately 65%. Women who have undergone hysteroscopic septum resection and have been reported in the different series comprise a highly selected group of symptomatic patients with term delivery and live birth rates of only approximately 5%. Hysteroscopic treatment seems to restore an almost normal prognosis for the outcome of their pregnancies with term delivery rates of approximately 75% and live birth rates of approximately 85%. It seems, therefore, that hysteroscopic septum resection can be applied as a therapeutic procedure in cases of symptomatic patients but also as a prophylactic procedure in asymptomatic patients in order to improve their chances for a successful delivery.