Milking the umbilical cord at term Cesarean section: Effect on hemoglobin levels in the first 48 hours of life

New evidence suggests immediate clamping of the umbilical cord may contribute to anemia of infancy. It can deprive a full-term infant of 25% of its blood volume, representing up to 50 mg/kg of iron. Poor iron stores can affect the developing brain. Immediate clamping is routine at cesarean section but lacks scientific evidence. Delayed clamping for two minutes can reduce anemia but is not always feasible at cesarean section. Cord milking may offer an alternative at cesarean section for the prevention of anemia. This pilot study, a partially-blinded randomized controlled trial, compared immediate clamping and cord milking in full-term infants at planned cesarean section. The primary outcome variable was hemoglobin and hematocrit levels at 36-48 hours of age. The secondary outcome variables were placental residual blood volume and undesired neonatal outcomes. Women and their infants were randomly assigned to immediate clamping (\u3c10 seconds) or cord milking (five milkings before clamping). Women were excluded if medically ill, severely anemic or known to smoke. Infants were excluded if congenital anomalies or intrauterine growth restriction. Twenty-four mother/infant pairs were randomized. Analyses revealed no differences in maternal and infant demographic variables. Infants with milking had significantly higher hemoglobin (p=0.03) and hematocrit (p=0.01) levels at 36-48 hours. Immediate clamping was associated with significantly greater placental residual blood volume (p=0.01). Although a small sample, there was no report of symptomatic polycythemia, admission to the neonatal intensive care unit or need for an exchange transfusion. Maximum serum bilirubin levels were similar between groups. Two of the infants in the milking group required phototherapy. One had ABO incompatibility and the other was readmitted for breastfeeding jaundice. There was a trend towards anemia (hematocrit ≤ 47%) at 36-48 hours in infants with immediate clamping (p=0.07). Cord milking is easy to implement at cesarean section and may aid in the prevention of anemia in infancy. While some clinicians focus on polycythemia, a parallel concern is the incidence of anemia found in infants with immediate clamping. Cord milking appears to be an effective alternative to delayed clamping with no associated harm. More research is needed to discern causes of hyperbilirubinemia