When to Cut the Umbilical Cord

Oct. 18, 2004 -- Premature babies may be less likely to need blood transfusions if their umbilical cords are cut a bit later than normal.

Waiting 30 seconds to 2 minutes before cutting the umbilical cord could make the difference, say researchers including Heike Rabe, MD, PhD, of Brighton and Sussex University Hospitals in Brighton, England.

The umbilical cord connects the baby to the mother's placenta, delivering oxygen-rich blood to the infant.

After the baby is born and before the placenta is delivered, the umbilical cord is clamped in two places and cut between the clamps.

There are no official standards about exactly when the umbilical cord should be clamped and cut.

Rabe and colleagues recently reviewed seven studies on the clamping and cutting of umbilical cords. The data are based on almost 300 babies, all of whom were born early (before the end of 37 weeks of pregnancy). Their study appears in the October issue of the journal The Cochrane Collaboration.

When to Separate Baby From Umbilical Cord

Delaying umbilical cord clamping by 30 to 120 seconds, rather than early clamping, seems to be associated with less need for transfusion and less bleeding in the infant's brain, according to the researchers.

Early clamping was defined as clamping in less than 30 seconds.

The extra time lets the baby get a little more blood from the placenta, which could reduce the need for a blood transfusion.

However, the strategy could have risks.

For instance, many premature babies need resuscitation, which is typically performed away from the mother. In those cases, the umbilical cord must be cut quickly to save the baby's life.

Waiting too long could also allow an excess of red blood cells to thicken a baby's blood, possibly stressing the newborn's heart and breathing or even prompting jaundice or brain damage, according to news reports.

The study did not address the practice of "milking" the umbilical cord before cutting it, a method used by some practitioners to coax placental blood in the umbilical cord into the baby.

The researchers also did not weigh in on whether it helps to hold the baby below the placenta, as some believe.

A longer-term study of umbilical cord clamping times in premature babies is under way.