Perinatal and Maternal Outcomes by Indication for Delivery in the Second Trimester

Abstract Perinatal and maternal morbidity in the setting of preterm birth may differ by delivery indication. We compared perinatal and maternal outcomes of second-trimester (240/7–276/7 weeks of gestation) deliveries indicated for preeclampsia with severe features (PE-SF), with those following preterm premature rupture of membranes (PPROM). Secondary analysis of an observational cohort study of singleton and twin preterm deliveries before 35 weeks' gestation at 33 hospitals across the United States. Singletons without congenital anomalies who were delivered due to PE-SF or PPROM from 240/7 to 276/7 weeks of gestation were included. The primary outcome was a composite of perinatal morbidity or death, defined as fetal or neonatal death, severe bronchopulmonary dysplasia (BPD) grade III, intraventricular hemorrhage (IVH) grade III to IV, necrotizing enterocolitis (NEC) stage IIA or greater, periventricular leukomalacia (PVL), retinopathy of prematurity (ROP) stage III to IV, or culture-proven sepsis. Secondary outcomes included components of the primary outcome, small-for-gestational-age (SGA) birth, and a composite of maternal morbidity. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated. Among the 7,515 in the original cohort, 164 deliveries for PE-SF and 119 deliveries following PPROM were included. Individuals with PE-SF were more likely to have a BMI of ≥30 kg/m2, hypertensive disorder of pregnancy in a prior pregnancy, chronic hypertension, and cesarean birth (p < 0.05) compared with those who delivered following PPROM. Composite perinatal morbidity or death did not differ between groups (aOR = 1.60, 95% CI: 0.89, 2.85, p = 0.11), but fetal death was significantly higher in the PE-SF group (aOR = 6.04, 95% CI: 1.42, 25.71). Neonates delivered for PE-SF were more likely to be SGA (aOR = 13.45, 95% CI: 2.92, 61.94). Composite maternal morbidity did not differ between groups (aOR = 1.18, 95% CI: 0.62, 2.26). Second-trimester preterm birth indicated for PE-SF was associated with a higher rate of fetal death than birth for PPROM. Composite neonatal and maternal morbidity did not differ by indication.