BACKGROUND: Caesarean section performed at full dilation (CSfd) has been associated with higher risk of spontaneous preterm birth (sPTB) in subsequent pregnancies. This review aimed to investigate the impact of a CSfd on subsequent pregnancies compared to all other modes of birth.. OBJECTIVES: To compare the risk of sPTB in a subsequent pregnancy following CSfd versus any other mode of birth in the index pregnancy. SEARCH STRATEGY: MEDLINE, EMBASE, PubMed, Cochrane Library and Google Scholar were searched electronically following PRISMA guidance. SELECTION CRITERIA: Eligible observational studies included women with at least two consecutive singleton births, where the first birth was at term (≥37 weeks). The exposure was CSfd versus any other birth mode in the index pregnancy, and the outcome was sPTB in the subsequent pregnancy. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed quality using the Newcastle-Ottawa Scale. Meta-analyses were performed using random effects models to synthesise pooled odds ratios (OR) for sPTB using RevMan software. MAIN RESULTS: Fourteen studies were included, pooling data from 708,102 women (1998-2022). Compared against any other mode of birth, CSfd was associated with a significantly increased risk of sPTB (OR 1.91 95% confidence interval (CI) 1.79, 2.04). Subgroup analyses showed doubled the odds of sPTB < 34 weeks gestation after CSfd (OR 2.90 95% CI: 2.49, 3.38). Risk of bias was low in the majority of included studies. CONCLUSIONS: We have demonstrated a clear relationship between CSfd and subsequent sPTB. This information may help to inform surveillance pathways, such as cervical length screening in future pregnancies.
Cameron et al. (Fri,) studied this question.