Previable Preterm Premature Rupture of the Membranes Reaching Viability: Canadian Outcomes.

OBJECTIVE

To determine timing of birth and neonatal outcomes after previable preterm premature rupture of the membranes (PPROM) <22 weeks versus no prolonged PPROM, to aid perinatal counselling at viability.

METHODS

We conducted a retrospective cohort study of 8071 liveborn singletons born <32 weeks between 2018-2022, who received active care and died in the resuscitation room or were admitted to a neonatal intensive care unit in Canada. Associations between previable PPROM and birth timing (and latency period) were investigated. Outcomes were compared between previable PPROM and no prolonged PPROM. Our primary outcome was a composite of mortality or severe neonatal morbidity (respiratory distress syndrome, severe neurological injury, severe necrotizing enterocolitis, severe retinopathy of prematurity, bronchopulmonary dysplasia, or sepsis). Multivariable generalized estimating equations accounted for the hospital effect.

RESULTS

225 infants experienced PPROM <22 weeks (65% born extremely preterm) and 7846 had rupture of membranes <24 hours at 22-31 weeks (36% born extremely preterm). As PPROM timing increased (≤16 to 21 weeks), median gestational age at birth decreased [27.5 weeks (IQR 24.5, 29.0) to 25.0 (IQR 23.0, 28.0)]. Previable PPROM infants had increased odds of mortality/severe neonatal morbidity (90%) versus those without prolonged PPROM (66%, adjusted OR 1.71, 95% CI 1.14 to 2.56), but 77% survived to discharge.

CONCLUSION

In our large cohort of previable PPROM reaching viability, gestational age at rupture and birth were inversely related. Most previable PPROM infants who reached viability and received active care were born extremely preterm, nearly all experienced severe morbidity, but three quarters survived.