Factors influencing survival in pre-viable preterm premature rupture of membranes

Objective: An observational study of a consecutive case series of pre-viable PPROM (16–24 gestational weeks) was performed between 2001 and 2007 in a single tertiary centre to identify factors that predict neonatal survival. Methods: Detailed obstetric, ultrasound and neonatal data were abstracted from clinical records. Univariate, multivariate and receiver operator curve (ROC) analyses were performed to identify predictors of neonatal survival to discharge. Results: A total of 143 cases of PPROM were identified. Survival to discharge was less with PPROM at 16–20 weeks than 20–24 weeks (17% versus 39%; p = 0.042). GA at PPROM, latency, mode of delivery and electronic foetal monitoring (EFM) were all significant, independent, predictors of survival (p < 0.05). Ultrasound assessed amniotic fluid index (AFI) was a poor predictor of survival (area under ROC = 0.649, 95% CI = 0.532–0.766). A multivariable predictive model, including GA at PPROM, latency, mode of delivery and EFM had an area under the ROC of 0.954 (95% CI = 0.916–0.993, sensitivity 97%, specificity 89% and accuracy 92%). Conclusion: Pre-viable PPROM has a poor prognosis, though modern neonatal management techniques may improve survival in late pre-viable PPROM. The predictive model generated from this consecutive case series of this rare condition provides valuable data for counselling patients with this condition.