The umbilical cord continues to work immediately after birth, transferring blood, oxygen, and stem cells while a baby adjusts to being outside the womb.
The review, published in The Lancet, looked at over 60 studies including more than 10,000 babies.
The first analysis compared what happened when the umbilical cord was clamped (cut) immediately after birth with the outcome if cord clamping was delayed by at least 30 seconds.
The second analysis looked at the impact of delaying cord clamping by specific amounts of time: 15-45 seconds (‘short deferral’); 45-120 seconds (‘medium deferral’) or 120 seconds or more (‘long deferral’).
The findings suggest that delaying clamping of the umbilical cord may reduce the risk of death in premature babies by a third compared to immediate clamping.
The researchers say that a longer delay appears to have the greatest impact, concluding: “Compared with immediate clamping, waiting at least two minutes before clamping the cord reduced the risk of death in premature babies by two thirds.”
Dr Anna Lene Seidler at the NHMRC Clinical Trials Centre, University of Sydney, Australia and one of the authors of the paper said:
“Our new findings are the best evidence to date that waiting to clamp the umbilical cord can save the lives of some premature babies."
Dr Sol Libesman, lead statistician for the study and research fellow at the NHMRC Clinical Trials Centre, said:
“Until recently, it was standard practice to clamp the umbilical cord immediately after birth for premature babies so they could be dried, wrapped, and if necessary, resuscitated with ease.
“Our study shows that there is no longer a case for immediate clamping and, instead, presently available evidence suggests that deferring cord clamping for at least two minutes is likely the best cord management strategy to reduce the risk of premature babies dying shortly after birth.”
The authors call for more research, stressing that their findings may not apply to premature babies who need immediate resuscitation ‘unless the hospital is able to provide safe initial breathing help with the cord intact’.
They say all of the studies were were carried out in hospitals with neonatal intensive care units, so ‘may not be generalisable to low-resource settings’.
Their findings also highlight the importance of ensuring premature babies are kept warm, with skin-to-skin contact where possible alongside delayed cord clamping.
Amina Hatia, Tommy’s Midwifery Manager, said:
“There is strong evidence that delaying cord clamping benefits babies. It ensures that immediately after they are born, they continue to receive blood being transferred from the placenta through the cord to baby.
“Delaying cutting the cord allows extra blood that is full of oxygen and nutrients, such as iron, to be passed onto your baby.
“That’s why delayed clamping is officially recommended, and why Tommy’s encourages discussing delayed cord clamping with your care team during pregnancy and as part of your birth plan.
“If you need support or information about this topic, please get in touch with us at Tommy’s.”
We’re here to offer support to anyone who has been affected by premature birth.
Our team of expert midwives are here for you. You can call them free on 0800 0147 800, Monday to Friday, 9am to 5pm.