99 Deferred cord clamping in very and extremely preterm monochorionic twins: A retrospective cohort study

Abstract Background The rate of multiple births has surged. Twins, especially those with monochorionic placentation, face a higher risk of neonatal mortality, morbidity and very preterm birth compared to singletons. Deferred cord clamping (DCC) is the standard for preterm singletons. While DCC is known to reduce the risk of mortality and morbidity in preterm singletons, its efficacy and safety in very preterm twins, especially monochorionic twins, remain scarcely explored. Objectives This study aimed to assess whether DCC, compared with early cord clamping (ECC), was associated with a reduction in death and/or severe brain injury in very and extremely preterm monochorionic-diamniotic twins. Design/Methods This multicenter retrospective cohort study included liveborn monochorionic-diamniotic twins of <32 gestational weeks admitted to a tertiary-level neonatal intensive care unit (NICU) in Canada between 2018 and 2023 using the Canadian Neonatal/Preterm Birth Network (CNN/CPTBN) database. We compared DCC ≥30s and ECC <30s. The primary outcome was a composite of death before discharge and/or severe brain injury. Secondary outcomes included neonatal morbidity and clinical outcomes. We calculated crude odds ratios (ORs) and adjusted ORs for categorical variables and ratio of means for continuous variables, along with 95% confidence intervals (CI). Models were fitted with generalized estimated equations accounting for twin correlation. Results 1017 neonates were included (DCC 488 [48.0%]; ECC 529 [52.0%]). Death and/or severe brain injury occurred in 10% (n=48) of twins who received DCC and in 16% (n=82) of those who received ECC. There was no significant difference between the groups (aOR 0.93; 95% CI 0.60-1.45). There was a significant reduction in red blood cell transfusions (aOR 0.46; 95% CI 0.33-0.66). Conclusion Among monochorionic-diamniotic twins born before 32 weeks of gestation, DCC did not impact the incidence of death and/or severe brain injury compared to ECC but was associated with decreased need for transfusions.