Uterus didelphys. Report of a case with torsion of the uterus occurring during labor.

In a 30-year-old primigravida with uterus didelphys there occurred, during labor, mutual torsion of the inferior lower uterine segments, the cervix of the pregnant right uterus crossing in front of the lower segment of the non-pregnant left uterus. This blocked the birth canal, and the patient had to be delivered by cesarean section. The frequency of major uterine malformations, their diagnosis, and role in the obstetric prognosis are discussed.