Deferred cord clamping in twins: A retrospective cohort study

Objectives A recent meta-analysis found a 30% mortality decrease in extremely preterm singletons randomized to receive deferred cord clamping (DCC). Data on DCC in twins are scant. Our primary objective was to determine whether DCC was associated with a decrease in death before discharge and/or severe neurological injury in survivors (SNI) in twins ≤29+6 weeks. Methods We conducted a retrospective study using the Canadian Neonatal/Preterm Birth Network database, comparing twins ≤29+6 weeks who received DCC ≥30 seconds and immediate cord clamping (ICC) <30 seconds. Our primary outcome was a composite of death and/or SNI (severe IVH-intraventricular hemorrhage grade III/IV and PVL-periventricular leukomalacia), and a complete set of secondary outcomes. We calculated adjusted odds ratios (aOR) for categorical and coefficients for continuous variables, and 95% confidence intervals (CI). Models were fitted with generalized estimated equations to account for clustering. Results We included 1597 infants from twin pairs; 624 received DCC (39.1%), and 973 (60.9%) received ICC. Death/SNI occurred in 17.8% (N=111) twins who received DCC and in 21.7% (N=211) who received ICC. Between twins who received DCC versus ICC, we did not find a significant difference in death/SNI (aOR 1.07, 95% CI 0.78–1.47). DCC was associated with decreased need for mechanical ventilation (aOR 0.51, 95% CI 0.39–0.67), delivery room intubations (aOR 0.53, 95% CI 0.42–0.68), transfusions (coefficient -0.49, 95% CI -0.86, -0.12) and NICU length of stay (coefficient -4.17, 95% CI -8.15, -0.19). Conclusions DCC was not associated with decreased death/SNI in twins ≤29+6 weeks but was associated with some other positive outcomes.