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.


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 < 0.005) after delayed clamping. Higher Hct values did not lead to fewer RBC transfusions (p > or = 0.70). Apgar scores after birth and daily SNAP scores were not significantly different (p > or = 0.22). Requirements for mechanical ventilation with oxygen were similar. More (p = 0.03) neonates needed phototherapy after delayed clamping, but initial bilirubin levels and extent of phototherapy did not differ.


CONCLUSIONS
Although a 1-minute delay in cord clamping significantly increased RBC volume/mass and Hct, clinical benefits were modest. Clinically significant adverse effects were not detected. Consider a 1-minute delay in cord clamping to increase RBC volume/mass and RBC iron, for neonates 30 to 36 weeks' gestation, who do not need immediate resuscitation.
Strauss
Ronald G
RG
Department of Pathology and Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA. ronald-strauss@uiowa.edu
Mock
Donald M
DM
Johnson
Karen J
KJ
Cress
Gretchen A
GA
Burmeister
Leon F
LF
Zimmerman
M Bridget
MB
Bell
Edward F
EF
Rijhsinghani
Asha
A
D003250:Constriction; D004911:Erythrocyte Volume; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D013997:Time Factors; D014470:Umbilical Cord