A randomized clinical trial comparing immediate versus delayed clamping of the umbilical cord in preterm infants: short-term clinical and laboratory endpoints

BACKGROUND: Most neonates less than 1.0 kg birth weight need red blood cell (RBC) transfusions. Delayed clamping of the umbilical cord 1 minute after delivery transfuses the neonate with autologous placental blood to expand blood volume and provide 60 percent more RBCs than after immediate clamping. This study compared hematologic and clinical effects of delayed versus immediate cord clamping. STUDY DESIGN AND METHODS: After parental consent, neonates not more than 36 weeks' gestation were randomly assigned to cord clamping immediately or at 1 minute after delivery. The primary endpoint was an increase in RBC volume/mass, per biotin labeling, after delayed clamping. Secondary endpoints were multiple clinical and laboratory comparisons over the first 28 days including Score for Neonatal Acute Physiology (SNAP). RESULTS: Problems with delayed clamping techniques prevented study of neonates of less than 30 weeks' gestation, and 105 neonates 30 to 36 weeks are reported. Circulating RBC volume/mass increased (p = 0.04) and weekly hematocrit (Hct) values were higher (p