(437) Factors associated with cesarean delivery following labor induction in pregnancies with preterm preeclampsia

Hypertensive disorders of pregnancy continue to be a major cause of maternal and perinatal morbidity. The treatment for preeclampsia is delivery. Labor induction should be considered given the potential for reduced maternal and neonatal risk. We aimed to identify factors associated with cesarean delivery in preterm pregnancies with preeclampsia.

Study Design:

This is a retrospective study of singleton pregnancies with preeclampsia who underwent labor induction prior to 37 weeks gestation at an academic center between 1/2018-12/2019. Medical records were reviewed for clinical and demographic data. Data was analyzed using chi-square, Fisher exact tests, Mann Whitney U, and student t test as appropriate. Logistic regression was used to control for confounders. P < 0.05 was considered significant. Data analysis was performed with SPSS software (version 27).

Results:

Of the 147 individuals meeting inclusion criteria, 19 (13.0%) had preeclampsia without severe features and 125 (85.6%) had preeclampsia with severe features. Following labor induction, 94 patients (63.9%) had a vaginal delivery and 53 patients (36.1%) had a cesarean section. Demographic data for the study groups are listed in Table 1. Patients with successful labor induction were more likely to identify as Caucasian (58.5% vs 39.6%, p=0.035) and have a prior vaginal delivery (51.1% vs 28.3%, p=0.007). Patients who had a vaginal delivery also had a lower body mass index (BMI) (32.8 vs 37.1 kg/m2, p=0.001) and a later gestational age at delivery (34.7 vs 33.5 weeks, p=0.001). The most common indications for cesarean section were arrest of dilation (41.5%), fetal distress (26.4%), and arrest of descent (15.1%). After controlling for confounders, BMI (OR 1.1, 95% CI 1.03-1.16) and gestational age (OR 0.7, 95% CI 0.54-0.86) were significant predictors for cesarean section (Table 2).

Conclusion:

Increased BMI and earlier gestational age may be predictors for failed labor induction in preterm pregnancies with preeclampsia and should be considerations for delivery planning. Additional studies are needed to corroborate these findings.