Results showed that children whose umbilical cords were cut three minutes after their birth tended to have slightly better fine motor and social skills at the age of four than those whose cords were cut immediately.
“There is growing evidence from a number of studies that all infants, those born at term and those born early, benefit from receiving extra blood from the placenta at birth,” said Dr Heike Rabe, neonatologist and senior lecturer at the Brighton and Sussex Medical School (BSMS), who wrote the editorial to the study published in the journal JAMA Pediatrics.
Dr Rabe has conducted previous studies on the effect of delayed clamping on pre-term infants.
By delaying the clamping of the cord, more blood can reach the baby from the placenta. This can increase the child’s blood volume by up to a third, and also increases iron storage – which helps brain development.
“The extra blood at birth helps the baby to cope better with the transition from life in the womb, where everything is provided for them by the placenta and the mother, to the outside world,” Dr Rabe said. “Their lungs get more blood so that the exchange of oxygen into the blood can take place smoothly.”
The study took place in Sweden among 263 full-term babies. Half of the group had their cords clamped immediately, and the other half had them clamped after three minutes.
The children were then followed up at the age of four, and were tested in IQ, motor skills, social skills, problem-solving, communication and behaviour.
Boys whose cords had been clamped after a delay showed modestly higher scores in social skills and fine motor skills. The girls, however, did not show any improvement in this area.
“We don’t know exactly why, but speculate that girls receive extra protection through higher estrogen levels whilst in the womb,” Dr Rabe said.
Previous studies have shown the benefits of delayed clamping to newborn babies, particularly those born preterm, but this is the first study to follow up term newborn babies past infancy.
Although recent research suggests that delayed clamping does not increase the risk of blood loss in the mother, as previously believed, it is still unclear whether it could harm infants’ health, and potential risks include jaundice and polycythemia, a high red blood count.
The World Health Organization recommends delayed cord clamping of at least one minute.
University of Sussex