The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

Abstract

Objective: To determine if a previous caesarean section increases the risk of unexplained antepartum stillbirth in second pregnancies.

Study design: Retrospective cohort study.

Setting: Large Canadian perinatal database.

Population: 158 502 second births.

Methods: Data were obtained from a large perinatal database, which supplied data on demographics, pregnancy complications, maternal medical conditions, previous caesarean section and pregnancy outcomes.

Main outcome measures: Total and unexplained stillbirth.

Results: The antepartum stillbirth rate was 3.0/1000 in the previous caesarean section group compared with 2.7/1000 in the previous vaginal delivery group (P= 0.46). Multivariate logistic regression modelling, including terms for maternal age (polynomial), weight >91 kg, smoking during pregnancy, pre-pregnancy hypertension and diabetes, did not document an association between previous caesarean section and unexplained antepartum stillbirth (OR 1.27, 95% CI 0.92-1.77).

Conclusion: Caesarean section in the first birth does not increase the risk of unexplained antepartum stillbirth in second pregnancies.