Uterine rupture is rare during pregnancy and its associated with high maternal and fetal mortality. The incidence rate of uterine rupture is 5,3 per 10000 deliveries among unselected pregnant women. The most common risk factor of uterine rupture is previous caesarean section and uterine surgery. Other risk factors include multiparity, a short length of time (less than 18 months) since the last caesarean section, the number of previous caesarean sections, single-layer closure instead of two-layer closure, placenta previa, fetal malpresentation, macrosomia, forced amnio-infusion, multiple gestation, cephalopelvic disproportion and the use of prostaglandins or oxytocin for labor induction.
In more than half of cases of ruptured unscarred uterus no evident risk factor can be found. Rupture of unscarred uterus is very rare, involving 1: 17,000–20,000 deliveries, however it’s associated with high rate of maternal and perinatal morbidity and mortality.