To reduce a baby's risk of anemia, doctors should wait a few minutes after birth before clamping the umbilical cord, a new study suggests.
Waiting at least three minutes to clamp the cords of healthy newborns improved their iron levels at 4 months of age, and reduced the baby's risk of developing iron deficiency. Before clamping, blood within the cord and in the placenta flows into the baby; clamping cuts off this flow. Previous research had suggested that delayed cord clamping could prevent iron deficiency. However, it was unclear whether earlier clamping might bring increased the risk of jaundice and other health complications.
To investigate the risks and benefits of cord clamping, researchers at the Hospital of Halland in Sweden studied 400 full-term infants.
Some had their umbilical cords clamped after at least three minutes, while others had them clamped less than 10 seconds after delivery.
At 4 months old, babies whose clamping was delayed had iron levels that were 45 percent higher on average than those who had their umbilical cords clamped immediately. There were also fewer cases of anemia in the group that experienced delayed clamping.
For every 20 babies whose clamping was delayed, one case of iron deficiency would be prevented, according to the study. Delayed cord clamping was not associated with any adverse health effects.
Iron deficiency and anemia are major health problems in young children around the world, and are associated with poor neurodevelopment. Young children are at particular risk because they have high iron requirements as they rapidly grow.
Delayed clamping may allow infants to receive a substantial blood transfusion from the placenta. "A term newborn held 10 cm [4 inches] below the level of the uterus during the first three minutes of life increases its blood volume by an average of 32 percent," the researchers said.
Delayed cord clamping "should be considered as standard care for full-term deliveries after uncomplicated pregnancies," the researchers said.
The study was published online yesterday (Nov. 15) in the British Medical Journal.
Pass it on: Doctors should wait at least three minutes before clamping a baby's umbilical cord after birth.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.