The hematological impact of umbilical cord milking versus delayed cord clamping in premature neonates: a randomized controlled trial.

Background: The hematological impact of umbilical cord milking (UCM) was compared to that of delayed cord clamping (DCC) as a faster placental transfusion technique for preterm neonates (between 24 and 34 + 6 weeks gestation). A comparison of important neonatal morbidities was also made.

Methods: This was an open-label randomized trial conducted from June 8, 2017, to April 22, 2019. Two hundred patients with preterm deliveries (24 and 34 + 6 weeks gestation) were assigned to the DCC or UCM group at random at a ratio of 1:1. The study power was 80% for a difference in the hematocrit value of 3% and Hb value of one gram, and an alpha error of 0.05.

Results: The following variables were analyzed in the comparison of UCM vs. DCC: first draw hemoglobin: 17.0 ± 1.9 vs. 16.8 ± 1.8 gm/dl (95% CI -0.75-0.29, P 0.383); first draw hematocrit: 55.6 ± 6.4 vs. 55.2 ± 6.4% (95% CI -2.18-1.38, P 0.659); peak hematocrit: 56.9 ± 6.4 vs. 56.3 ± 6.7% (95% CI -2.41-1.26, P 0.537); the need for respiratory assistance (47% vs. 30%, P 0.020), inotropes (16% vs. 6%, P 0.040), and blood transfusion (26% vs. 12%, P 0.018); and the occurrence of intraventricular hemorrhage (9% vs. 5%, P 0.407), necrotizing enterocolitis (6% vs. 2%, P 0.279), sepsis (25% vs. 15%, P 0.111), and neonatal death (13% vs. 4%, P 0.40).

Conclusion: UCM facilitated a rapid transfer of placental blood equivalent to that of DCC for premature neonates. However, it resulted in increased rates of interventions and morbidities, especially in extremely preterm neonates.

Trial Registration: The clinical trial was registered on May 10, 2017, with registration number (NCT03147846).