ABSTRACT: Two measures to prevent anemia in infants are delayed cord clamping (DCC) and umbilical cord milking (UCM), both of which allow transfer of additional blood volume and hemoglobin (Hgb) from the placenta to the newborn. Umbilical cord milking and DCC generate comparable increases in Hgb in premature babies, but data are lacking for the effect of UCM in full-term neonates. This single-center, randomized controlled trial was designed to investigate the effect of UCM compared with early cord clamping on hematologic parameters at 6 weeks of age among term and near-term neonates.
Infants were more than 34 weeks 6 days’ gestation and delivered by low uterine segment transverse cesarean or vaginal delivery. In the UCM group, the cord was cut at ∼25 cm of length from umbilical stump within 30 seconds of birth. The umbilical cord was raised and milked from the cut end toward the infant 3 times at 10 cm/s and then clamped 2 to 3 cm from the umbilical stump. In controls, the cord was clamped within 30 seconds near the umbilicus and cut without milking. The 2 groups received routine postnatal care. Primary outcomes were Hgb and serum ferritin levels at 6 weeks postnatally. Secondary outcomes included clinical parameters in the first 48 hours; presence of respiratory distress, jaundice requiring phototherapy, polycythemia, and jitteriness in 48 hours; and Hgb, packed cell volume at 12 and 48 hours and bilirubin level at 48 hours. Group means of continuous normally distributed data were compared using an unpaired Student t test. Categorical data were compared using a χ2/Fisher exact test.
Of 700 births, 200 neonates met inclusion criteria, and 100 were randomized to each group; 171 (120 term and 51 near-term) completed the study. Baseline demographic characteristics of the groups were comparable. At 6 weeks, the mean ferritin and Hgb levels in the UCM group were 355.9 ± 182.6 μg/L and 11.9 ± 1.5 g/dL, respectively, and 177.5 ± 13.8 μg/L and 10.8 ± 0.9 g/dL in the controls (P < 0.05). Similar results were observed in term and near-term infants analyzed separately. Mean Hgb and hematocrit at 12 and 48 hours were significantly higher in the intervention group (P = 0.0001). Mean blood pressures at 30 minutes, 12 hours, and 48 hours were significantly higher, but within reference range, in the UCM group. The 2 groups did not differ significantly in heart rate, respiratory rate, and serum bilirubin. None of the newborns required neonatal intensive care unit admission or phototherapy, and none had polycythemia. Mean bilirubin levels at 48 hours were 7.4 and 6.6 mg/dL in the UCM and control groups, respectively (P > 0.05). No significant differences were found when near-term babies were examined for adverse outcomes.
Umbilical cord milking is safe and increases Hgb and iron levels at 6 weeks, without significant adverse effects. Umbilical cord milking can be used routinely or when cord clamping cannot be delayed. Studies with longer follow-up are needed to assess the sustainability of the advantage in Hgb and ferritin later in infancy. Another study is needed to compare UCM with DCC in term babies.