Influence of maternal factors and mode of induction on labour outcomes: a pragmatic retrospective cohort study

Since recent research indicates that other modalities are at a minimum non-inferior to the NICE-recommended hormonal agent prostaglandin E2 (PGE2), a retrospective cohort study was conducted on 1971 consecutively induced singleton pregnancies. The multinominal regression showed that the odds ratio (OR) for vaginal delivery with balloon-mediated labour induction (84% vaginal deliveries; OR 1.6; 95% CI 0.7–3.5) is similar to the PGE2 agents propess (81%; OR 1.2; 95% CI 0.68–1.98) and prostin (79%; OR 0.99; 95% CI 0.55–1.79) when using a triple multi-agent induction as a reference. On the other hand, combining the propess and prostin (60% vaginal deliveries; OR 0.45; 95% CI 0.21–0.96) and attempting quadruple combinations of the induction modalities (56%; OR 0.37; 95% CI 0.16–0.85) yields significantly poorer outcomes. However, compared to the known factors associated with increased caesarean section rates, such as an increased maternal age, nulliparous pregnancies and a history of caesarean section, the differential impact of different induction modalities appears as less pronounced.