Delayed cord clamping vs cord milking in elective cesarean delivery at term: a randomized controlled trial

Delayed cord clamping has significant beneficial effects on the neonate and its transition to extrauterine life and, therefore, is common practice at vaginal births in the Netherlands. In 2015, 16% of neonates were born via cesarean delivery; moreover, in 81% of these cases, the umbilical cord was clamped and cut immediately. Neonatal benefits of delayed cord clamping are an increased circulating volume of 25 to 30 mL/kg, leading to a higher preload of both the right and left ventricles during the transition from umbilical circulation to pulmonary circulation, thus maintaining a stable left ventricle output, and to higher neonatal hemoglobin and hematocrit levels 24 to 48 hours after birth. Currently, little is known about whether the abovementioned neonatal benefits of delayed cord clamping could apply to neonates delivered by cesarean delivery. In these cases, possible negative effects on neonatal outcomes (ie, neonatal hypothermia, lower Apgar scores, and hyperbilirubinemia) and maternal outcomes (ie, increased maternal blood loss and higher postoperative infection rate) should also be taken into consideration.

This study aimed to determine whether clamping the umbilical cord after 2 minutes is superior to cord milking during elective cesarean deliveries at term, taking both short- and long-term neonatal and maternal outcomes into consideration, and to determine whether cord milking could be an appropriate alternative to delayed cord clamping.

A randomized controlled trial was conducted in a large secondary care center in the Netherlands (Amphia Hospital in Breda) from October 2020 to April 2022. A total of 115 patients who underwent an elective cesarean delivery between 37 0/7 and 41 6/7 weeks of gestation were included. The primary outcomes were neonatal hemoglobin and hematocrit levels at 48 hours after birth. The secondary outcomes were divided into neonatal and maternal outcomes.

After randomization, 58 participants were treated with cord milking, and 57 participants were treated with delayed cord clamping. There was no significant difference in demographic characteristics between both groups. There was no significant difference in the primary outcomes, with a mean hemoglobin level 48 hours after birth of 12.1 mmol/L in the delayed cord clamping group and 12.2 mmol/L in the cord milking group (P=.80). Regarding our secondary outcomes, there was no significant difference regarding Apgar score, neonatal body temperature, maternal blood loss, and postoperative infection rate between our intervention groups.

Hemoglobin and hematocrit levels at 48 hours after birth showed no significant difference when comparing delayed cord clamping with cord milking. Delayed cord clamping did not lead to increased maternal blood loss or postoperative infections compared with a method with a much shorter timeframe between delivery and clamping of the umbilical cord, namely, cord milking. In addition, delayed cord clamping did not lead to a lower Apgar score or neonatal temperature compared with cord milking. Our research suggests that delayed cord clamping can be safely performed during elective cesarean deliveries at term. If intraoperative circumstances do not allow for delayed cord clamping, cord milking can be an appropriate alternative for the neonate at term.