A 2-center randomized controlled trial funded by the National Institutes of Health may make the case for using umbilical cord “milking” to improve blood flow in preterm infants who were delivered via cesarean.
In the trial, infants who were delivered by cesarean were randomly assigned to either undergo delayed cord clamping (lasting from 45 to 60 seconds) or umbilical cord milking, which consisted of 4 strippings. Infants delivered vaginally were separately randomly assigned to receive either umbilical cord milking or delayed cord clamping. At one of the 2 centers, continuous hemodynamic measurements and echocardiography were performed.
Overall, there were 197 infants enrolled (mean gestational age 28 weeks ± 2 weeks), of whom 154 were delivered via cesarean. Umbilical cord milking was performed on 74 infants; delayed cord clamping was performed on 79 infants. Infants who received umbilical cord milking showed higher superior vena cava flow and right ventricular output in the first 12 hours of life. They also showed higher hemoglobin levels, delivery room temperature, and blood pressure in the first 15 hours; urine output in the first 24 hours of life was also higher. No differences were seen between the 2 methods among the 43 infants delivered vaginally.
The investigators concluded that umbilical cord milking may be a more efficient technique to improve blood volume in preterm infants born via cesarean delivery. They also stated that this was the first randomized controlled trial to demonstrate higher systemic blood flow with umbilical cord milking when compared with delayed cord clamping.