Background Second trimester pregnancy induction with misoprostol in women with prior caesarean delivery is not well studied.
Objective To estimate the risk of uterine rupture using misoprostol as an induction agent for pregnancy termination in the second trimester of pregnancy in women with prior caesarean delivery.
Search strategy Cases of women with a history of prior caesarean delivery and subsequent misoprostol induction for pregnancy termination in the second trimester (16–28 weeks) were obtained from two main data sources. First, a retrospective chart analysis was performed at Thomas Jefferson University Hospital and Christiana Hospital between 1998 and 2004. Second, multiple Medline, Scopus and POPLINE literature searches were performed.
Selection criteria Case series and cohort studies of women with one or more prior caesarean delivery (of any type), and with a subsequent pregnancy with induction of labour for pregnancy termination at 16–28 weeks using misoprostol as the initial primary agent were included. Case reports were analysed separately.
Data collection and analysis Total cases were analysed by type and number of prior caesarean delivery, for the primary outcome of uterine rupture.
Main results The incidence of uterine rupture associated with second trimester misoprostol termination was 0.4% (2/461) in women with one prior low transverse, 0% (0/46) in those with two prior low transverse and 50% (1/2) in those with a prior classical caesarean delivery. One of the cases of uterine rupture in a woman with a prior low transverse caesarean required transfusion. None of the total eight cases (including case reports) of uterine rupture was associated with hysterectomy.
Conclusions Second trimester misoprostol termination appears safe among women with one prior low transverse caesarean birth, as it is associated with incidences of uterine rupture of 0.4% (95% confidence interval 0.08–1.67%), of hysterectomy of 0% and of transfusion of 0.2%. There are insufficient data on risk with more than one prior caesarean birth or with prior classical caesarean birth.