It allows blood to flow from the placenta to the baby whilst the baby’s lungs fill with air, potentially easing the transition into breathing.

Waiting for two minutes or longer to clamp the umbilical cord of a premature baby likely reduces the risk of death soon after birth, according to two companion systematic reviews and meta-analyses recently published in The Lancet. 

“Worldwide, almost 13 million babies are born prematurely each year and, sadly, close to one million die shortly after birth. Our new findings are the best evidence to date that waiting to clamp the umbilical cord can save the lives of some premature babies. We are already working with international guideline developers to make sure these results are reflected in updated guidelines and clinical practice in the near future,” said first author Dr Anna Lene Seidler from the NHMRC Clinical Trials Centre, University of Sydney, Australia.

Deferring clamping of the umbilical cord allows blood to flow from the placenta to the baby whilst the baby’s lungs fill with air. This is thought to potentially ease the transition into breathing and to reduce the risk of iron deficiency in the infant.

Meta-analysis of 3,292 infants across 21 studies finds that premature babies whose umbilical cord is clamped 30 seconds or more after birth are less likely to die before leaving the hospital, compared to those whose cord is clamped immediately after birth. A second companion meta-analysis of 47 trials including 6,094 babies suggests that waiting at least two minutes before clamping the cord of a premature baby may reduce the risk of death compared to a lesser waiting time.

Researchers believe that these results can inform a change in clinical practice, leading to teams of midwives and doctors working together to defer clamping the umbilical cord while ensuring that the baby is warm, breathing, and cared for.