G133(P) Persistent pulmonary hypertension in newborns following preterm rupture of membranes- a case series

Abstract

Historically it has been understood that babies born after a prolonged period of oligohydramnios, secondary to PROM at an early gestation, have pulmonary hypoplasia which leads to severe respiratory failure. We present a case series of infants with a history of PROM who presented in the first few hours of life with severe respiratory failure and were treated with iNO. The clinical response to iNO suggests that the underlying cause of the respiratory failure is predominantly PPHN rather than pulmonary hypoplasia. 13 infants with Gestational age range 26–29 weeks had SROM ranging from 15–27 weeks gestation. Median duration of ROM was 39 days. In the nine cases in whom antenatal information was available, four had a history of oligohydramnios and four had anhydramnios. In five there was evidence of chorioamnionitis on placental pathology, of whom four had clinical chorioamnionitis prior to delivery. Oxygenation index (OI) just prior to iNO ranged from 112–552 and the reduction in OI after starting iNO can be seen in Figure 1. There is no difference in days on ventilation when compared to gestation matched controls without PROM, but they appear to require supplementary oxygen for longer. This case series demonstrates a marked improvement in hypoxic respiratory failure in babies with PPROM and oligohydramnios (regardless of gestation), providing evidence that the aetiology is primarily PPHN. This is supported by the paper which demonstrates a reduction in Nitric Oxide Synthetase following PROM. We suggest that, where possible, mothers with PROM and oligohydramnios should be delivered in a tertiary referral centre where iNO therapy is immediately available.