Vaginal delivery after labor induction in women with hypertensive disorders of pregnancy: a retrospective cohort study

Objective Hypertensive disorders of pregnancy (HDP) is a prevalent complication and a leading cause of maternal and perinatal mortality.The definitive treatment for HDP is delivery of the placenta, halting disease progression. While vaginal delivery is possible for most HDP patients, there is no standardized protocol for labor induction in these cases. The objective was to investigate and compare the outcomes of vaginal delivery after labor induction and to explore the optimal approach to vaginal trial in women in women with HDP. Methods This was a retrospective cohort study of 894 pregnant women with HDP who underwent vaginal trial. 380 were in the spontaneous labor group and 514 were in the induced labor group (including 328 in the propess group(induced by dinoprostone) and 178 in the oxytocin group). The primary outcome was mode of delivery. The secondary outcomes included other maternal and infant outcomes. Multivariable log-binomial models were used to assess the relative risk and 95% confidence intervals. Results 89.7% of patients had successful vaginal delivery. The rate of vaginal delivery was lower in the induced labor group compared to the spontaneous labor group (85.6% vs. 95.3%, p = 0.001), and the risk of cesarean section was 2.706 times higher in the induced labor group after adjusting for confounding factors (RR: 2.706, 95%CI: 1.318–5.558). The total and first stages of labor were longer in the induced labor group, and intrapartum antihypertensive use and postpartum urinary retention were more frequent in the induced labor group. A stratified analysis of maternal age, pre-pregnancy body mass index, and cervical Bishop score indicated a 11% increased risk of cesarean section following labor induction in HDP patients aged ≥ 35 years (RR: 1.110, 95%CI: 1.008–1.572).There was no difference in all outcomes between the propess and oxytocin groups. Conclusions While labor induction raises the likelihood of cesarean section following vaginal trial in patients with hypertensive disorders of pregnancy, particularly those over 35, it remains a safe and viable option with a high success rate for vaginal delivery. Both dinoprostone and oxytocin can be utilized as planned induced labor methods for HDP patients, with comparable safety and efficacy profiles.