Hemodynamic Changes with Umbilical Cord Milking in Nonvigorous Newborns: A Randomized Cluster Cross-over Trial

Abstract

To assess the hemodynamic safety and efficacy of umbilical cord milking (UCM) compared with early cord clamping (ECC) in non-vigorous newborn infants enrolled in a large multicenter randomized cluster-crossover trial. Two-hundred-twenty-seven non-vigorous term/near-term infants who were enrolled in the parent UCM vs. ECC trial consented for this sub-study. An echocardiogram was performed at 12±6 hours of age by sonographers blinded to randomization. The primary outcome was left ventricular output (LVO). Pre-specified secondary outcomes included measured superior vena cava (SVC) flow, right ventricular output (RVO), peak systolic strain, and peak systolic velocity by tissue doppler of the RV lateral wall and the interventricular septum. Non-vigorous infants receiving UCM had increased hemodynamic echocardiographic parameters as measured by higher LVO (225±64 vs. 187±52 ml/kg/min, p<.001), RVO (284±88 vs. 222±96 ml/kg/min, p<.001) and SVC flow (100±36 vs. 86±40 ml/kg/min, p<.001) compared with the ECC group. Peak systolic strain was lower (-17±3 vs. -22±3%, p<.001) but there was no difference in peak tissue doppler (.06 (.05, .07) vs. .06 (.05, .08) m/s). (s): Umbilical cord milking increased cardiac output (as measured by LVO) compared with ECC in non-vigorous newborns. Overall increases in measures of cerebral and pulmonary blood flow (as measured by SVC and RVO flow respectively) may explain improved outcomes associated with UCM (less cardiorespiratory support at birth and fewer cases of moderate-to-severe HIE) among non-vigorous newborn infants.