Exposure to umbilical cord management approaches and death or neurodevelopmental impairment at 22-26 months' corrected age after extremely preterm birth

Objective: To compare death or severe neurodevelopmental impairment (NDI) at 22-26 months' corrected age (CA) among extremely preterm infants following exposure to different forms of umbilical cord management. Design: Retrospective study. Setting: Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network registry. Patients: Infants born <27 weeks' gestation in 2016-2018 without severe congenital anomalies who received active treatment after birth and underwent neurodevelopmental assessments between 22 and 26 months' CA. Exposures: Immediate cord clamping (ICC), delayed cord clamping (DCC) or umbilical cord milking (UCM). Main outcomes and measure: Primary composite outcome of death or severe NDI at 22-26 months' CA, defined as severe cerebral palsy, Bayley-III cognitive/motor composite score <70, bilateral deafness or blindness; individual components were examined as secondary outcomes. Multivariable regression examined associations, adjusting for risk factors identified a priori and potential confounders. Mediation analysis explored the effect of severe intraventricular haemorrhage (IVH) on the exposure-outcome relationship. Results: Among 1900 infants, 64.1% were exposed to ICC, 27.8% to DCC and 8.1% to UCM. Compared with ICC-exposed infants, DCC-exposed infants had lower odds of death or severe NDI (adjusted OR 0.64, 95% CI 0.50 to 0.83). No statistically significant differences were observed when comparing UCM with either ICC or DCC, or between secondary outcomes across groups. Association between cord management and the primary outcome was not mediated by severe IVH. Conclusion: Compared with ICC, DCC exposure was associated with lower death or severe NDI at 22-26 months' CA among extremely preterm infants, which was not mediated by severe IVH.