Ready, Set, Clamp the Umbilical Cord

Iron levels in babies may be better with delayed umbilical cord clamping after birth

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) For nine months, mothers provide every bit of nutrition a developing baby needs while in the womb. When the baby meets the world, though, it's time to cut the cord — literally.

A recent study found that a minute or two difference in when the umbilical cord is clamped may affect a baby's health.

Waiting longer than one minute after birth to clamp the cord appeared to ensure better iron levels in babies' blood, but not without an increased risk of jaundice.

Cord clamping should only be delayed if jaundice phototherapy treatment is available, the study authors wrote.

"Discuss cord clamping timing with your OB/GYN."

This study, led by Sue J. McDonald, a professor of midwifery at LaTrobe University's School of Nursing and Midwifery in Australia, looked at the effects of timing on clamping a baby's umbilical cord.

When a baby is born, it is still connected to the mother's placenta (the baby's food source) by the umbilical cord.

Clamping the cord immediately after a baby is born might mean the baby gets a little less extra blood from the mother. The mother's blood is beneficial for the baby because it contains iron.

Waiting longer than a minute to clamp the cord, however, might make it more likely for the baby to develop jaundice.

Jaundice is the condition that makes newborns look yellowish because of having too much bilirubin in the blood. Bilirubin is produced when red blood cells break down.

If the bilirubin builds up faster than the baby's liver can dispose of it, then the baby can develop jaundice. Jaundice can cause long-term disabilities if not treated.

Phototherapy, or treatment with light, is used to help eliminate bilirubin in the blood.

In this study, the researchers reviewed 15 past research trials that involved a total of 3,911 pairs of mothers and their newborns.

The trials compared clamping the umbilical cord early after birth (within one minute) to clamping it late (after one minute).

The researchers found that the time it was clamped did not make any difference when it came to a woman's risk of hemorrhage. In other words, a woman was not more likely to bleed heavily if the cord was clamped early or late.

The researchers found that the timing of the cord clamping also did not make a difference in terms of the newborn's survival.

Similarly, newborns were not at higher risk for needing the neonatal intensive care unit (NICU) or to have a low health score after birth based on when their cords were clamped.

As expected, infants with an earlier cord clamping did not get jaundice as often as those with late cord clamping. Among 2,324 babies, those with an earlier cord clamping were 38 percent less likely to need phototherapy to treat jaundice than those with a later clamping.

However, babies whose cords were clamped earlier were twice as likely, compared to those with late clamping, to not have enough iron in their blood when they were 3 to 6 months old.

One important role iron has is carrying oxygen throughout the body in a substance called hemoglobin in the red blood cells.

Not having enough iron can lead to a condition called anemia, which can cause fatigue and other health issues.

Those babies whose cords were clamped earlier also had lower levels of hemoglobin one to two days after birth than those whose cords were clamped later.

After two days, there were no differences in baby's hemoglobin levels based on when their cords were clamped.

Only one study compared children's long-term brain development based on when their cords were clamped. This study found no difference between children whose cords were clamped early and those whose cords were clamped late.

Taking all these findings into account, the researchers determined that clamping the umbilical cord slightly later than one minute appears to be beneficial for newborns.

The authors stated that there is "growing evidence that delayed cord clamping increases early hemoglobin concentrations and iron stores in infants."

Even though clamping the cord later might increase the risk of jaundice, the authors wrote that "delayed cord clamping is likely to be beneficial as long as access to treatment for jaundice requiring phototherapy is available."

This study was published July 10 in the Cochrane Library.

The research was funded by the Department of Health and Ageing in Australia, the National Health and Medical Research Council in Australia and the National Institute for Health Research in the United Kingdom.

Reviewed by: 
Review Date: 
July 10, 2013
Last Updated:
July 30, 2013