Objective: To evaluate pregnancy outcome and the role of the amount of amniotic fluid (AF) in the prognosis of extremely preterm (<24 weeks) premature rupture of membranes (EPPROM).
Study design: Women with EPPROM and on-going pregnancy after 1 week of expectant management were included.
Exclusion criteria: fetal anomalies, termination of pregnancy and spontaneous recovery of AF within the first week. The effect of the large vertical pocket (LVP) on pregnancy outcome was assessed by a Cox regression model which included three covariates: LVP measurements from rupture to 24 weeks, gestational age at rupture of membranes and sealing procedure.
Results: Thirty-seven women were included in the study. The overall survival rate after the neonatal period was 40.5% (15/37) which increased to 62.5% (15/24) in neonates born alive after 24 weeks of gestation. Mean and S.D. of gestational age at rupture of membranes were 19.0 (+/-3.8) weeks. From rupture to 24 weeks, the pooled mean and standard deviation of LVP were 20.5 (+/-15.4)mm. Multivariate analysis showed that the likelihood for neonate survival increased by 2.7 (95% CI 1.45-4.65) for each 5mm of LVP during the follow-up from rupture to 24 weeks. After controlling for AF amount, neither the gestational age at rupture nor the sealing procedure showed any significant effect on pregnancy outcome.
Conclusion: Although the prognosis of EPPROM is poor overall, survival improves as the amount of AF before 24 weeks increases.