Umbilical Cord Milking Versus Delayed Cord Clamping in Preterm Infants

TLDR

Delayed cord clamping is recommended for preterm infants to increase blood volume, but its effectiveness may be reduced in cesarean deliveries compared to vaginal births. This study aimed to assess whether umbilical cord milking improves systemic blood flow in infants under 32 weeks born by cesarean section versus delayed cord clamping. In a two‑center randomized trial, cesarean‑delivered infants were assigned to either four‑strip cord milking or 45‑60‑second delayed clamping, with continuous hemodynamic monitoring and echocardiography performed on 197 infants. Cord milking produced higher superior vena cava flow, right ventricular output, hemoglobin, temperature, blood pressure, and urine output during the first 24 hours in cesarean infants, with no differences in vaginal deliveries, demonstrating that cord milking more efficiently increases systemic blood flow in preterm infants delivered by cesarean.

Abstract

Delayed cord clamping (DCC) is recommended for premature infants to improve blood volume. Most preterm infants are born by cesarean delivery (CD), and placental transfusion may be less effective than in vaginal delivery (VD). We sought to determine whether infants <32 weeks born by CD who undergo umbilical cord milking (UCM) have higher measures of systemic blood flow than infants who undergo DCC.This was a 2-center trial. Infants delivered by CD were randomly assigned to undergo UCM or DCC. Infants delivered by VD were also randomly assigned separately. UCMS (4 strippings) or DCC (45-60 seconds) were performed. Continuous hemodynamic measurements and echocardiography were done at site 1.A total of 197 infants were enrolled (mean gestational age 28 ± 2 weeks). Of the 154 infants delivered by CD, 75 were assigned to UCM and 79 to DCC. Of the infants delivered by CD, neonates randomly assigned to UCM had higher superior vena cava flow and right ventricular output in the first 12 hours of life. Neonates undergoing UCM also had higher hemoglobin, delivery room temperature, blood pressure over the first 15 hours, and urine output in the first 24 hours of life. There were no differences for the 43 infants delivered by VD.This is the first randomized controlled trial demonstrating higher systemic blood flow with UCM in preterm neonates compared with DCC. UCMS may be a more efficient technique to improve blood volume in premature infants delivered by CD.