Objective: To assess the natural history and contemporary outcomes in pregnancies complicated by previable preterm premature rupture of membranes (PROM).
Methods: Retrospective study of all women with a singleton or twin pregnancy admitted to a single tertiary referral center who experienced preterm PROM between 20 and 23 6/7 weeks of gestation during 2004-2014 and underwent expectant management. Women electing termination of pregnancy and pregnancies complicated by major fetal anomalies were excluded. Severe neonatal morbidity was defined as a composite of bronchopulmonary dysplasia, severe neurologic injury, or severe retinopathy of prematurity. Long-term follow-up to a corrected age of 18-21 months was available for the majority of surviving neonates.
Results: Of the 140 neonates born to women with previable preterm PROM during the study period, 104 were eligible for the study. Overall 51 (49.0%, 95% confidence interval [CI] 39.4-58.6%) newborns survived to discharge, of whom 24 (47.1%, 95% CI 33.4-60.8%) experienced severe neonatal morbidity. The overall rate of long-term morbidity among surviving neonates was 23.3% (95% CI 11.7-34.9%) and was significantly higher among neonates who previously experienced severe neonatal morbidity compared with those who did not (39.1% compared with 10.0%, P=.04). The only two factors that were significantly associated with overall survival and survival without severe neonatal morbidity were gestational age at preterm PROM of 22 weeks or greater (adjusted odds ratio [OR] 12.2, 95% CI 3.3-44.8 and adjusted OR 4.8, 95% CI 1.2-19.3, respectively) and a latency period of greater than 7 days (adjusted OR 10.1, 95% CI 3.2-31.6, and adjusted OR 6.7, 95% CI 2.2-21.0, respectively). Expectant management was associated with maternal risks including placental abruption (17.3%, 95% CI 10.0-24.6%) and sepsis (4.8%, 95% CI 0.7-8.9%).
Conclusion: Expectant management in pregnancies complicated by previable preterm PROM between 20 and 23 6/7 weeks of gestation is associated with an overall neonatal survival rate of 49.0%, high risk of short- and long-term severe morbidity among survivors, and carries considerable maternal risks.