Transabdominal cerclage placement in patients with prior uterine incisions: risk of scar disruption.

The object of this study was to describe pregnancy outcomes in women who had a transabdominal cerclage (TAC) placed after a prior uterine incision due to caesarean section or hysterotomy. This is a retrospective observational study of 57 women referred to a maternal-fetal medicine specialist (JES) for TAC placement after a previous uterine incision from 1989-2012. Pregnancy outcomes post-TAC placement are reported, including gestational age at delivery, survival rate and complications directly related to labour and the previous uterine scar. Of 51 women who had a prior uterine incision and were pregnant at TAC, 49 (96.1%) delivered viable infants at a mean gestational age of 35.9 weeks. One patient had intrauterine fetal demise at 16 weeks for causes likely unrelated to TAC and another had uterine rupture associated with a unicornuate uterus and advancing labour at 31 weeks. This study includes women with low transverse incisions, classical uterine incisions and higher order multiples. It was concluded that in women with a prior uterine incision, placement of a TAC is associated with low risk (2%) of uterine rupture.