Uterine rupture

This occurs once in approximately every 1500 deliveries in the UK. This condition is much more common in parts of Africa where the incidence is approximately 1 in 100 deliveries.

Rupture may occur apparently spontaneously or it may result from trauma before or during labour.

Uterine scars are a risk factor for rupture.

Scar rupture:

• classical CS causes 2% rupture in subsequent pregnancies
• LSCS is associated with 0.2% rupture
• previous myomectomy or hysterotomy are associated with increased rupture rates

Risk factors for rupture, in the absence of uterine scars:

• multiparity
• cephalopelvic disproportion
• syntocinon augmentation of labour

Fetal mortality and maternal mortality:

• there is an approximate 5% maternal mortality and 30% fetal mortality associated with this condition

Note that a model attempting to identify risk of uterne rupture concluded that:

• factors that were available before or at admission for delivery cannot be used to predict accurately the relatively small proportion of women at term who will experience a uterine rupture during an attempted vaginal birth after cesarean delivery (1)

Reference:

• 1. Grobman WA et al ; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.Prediction of uterine rupture associated with attempted vaginal birth after cesarean delivery. Am J Obstet Gynecol. 2008 Jul;199(1):30.e1-5