Am Fam Physician. 2005;71(11):2091-2092
Clinical Question
What is the optimal time to clamp the umbilical cord for infants born at less than 37 weeks’ gestation?
Evidence-Based Answer
In preterm infants, clamping the umbilical cord between 30 seconds and two minutes after delivery is associated with lower rates of blood transfusion and intraventricular hemorrhage.
Practice Pointers
Many patients request delayed umbilical cord clamping in their birth plans. Delayed cord clamping allows continued perfusion while the baby transitions to newborn circulation. However, when an infant is high risk, physicians frequently clamp and cut the cord early to allow the neonatal resuscitation team quicker access.
Rabe and colleagues reviewed the literature to determine the impact of early and delayed cord clamping on outcomes in preterm infants. They found seven randomized controlled trials that compared early and delayed cord clamping in a total of 297 preterm infants. Delaying cord clamping up to two minutes was associated with a higher hematocrit at four hours of life than early clamping (weighted mean difference: 5.31 g), fewer blood transfusions for anemia (25 versus 52 percent) and hypotension (20 versus 50 percent), and fewer intraventricular hemorrhages (17 versus 26 percent). All of these differences were significant. No statistically significant differences in respiratory outcomes were reported. However, the numbers of patients in the studies that reported this outcome were small.
Results for term infants also appear to be favorable. Van Rheenen and colleagues1 reviewed the literature on delayed cord clamping in term infants, and found that delaying cord clamping reduced anemia at two to three months of age. The results showed a 12 percent increased risk of hyperbilirubinemia, but in no study was this condition reported to require treatment.
An alternative to early cord clamping for resuscitation access is to deliver the baby without breaking down the bed. This allows resuscitation personnel and equipment to be brought to the bedside before the cord is clamped.