Delayed umbilical cord clamping could reduce risk of death in premature babies

Waiting for at least 2 minutes at birth to clamp the umbilical cord of premature babies could decrease their risk of death by more than half compared with immediate clamping.

Unlike babies born at full term, for whom delayed cord clamping is now recommended routine practice, best clinical practice has remained uncertain for preterm babies (those born alive before 37 weeks of pregnancy)

New findings, published today in 2 companion papers in The Lancet, will help to inform updated national and international guidelines. To the researchers’ knowledge, this is the most comprehensive review of umbilical cord clamping strategies at preterm birth to date.

“Worldwide, almost 13 million babies are born prematurely each year and, sadly, close to 1 million die shortly after birth. Our new findings are the best evidence to date that waiting to clamp the umbilical cord can help save the lives of some premature babies,” says first author Dr Anna Lene Seidler at the National Health and Medical Research Council (NHMRC) Clinical Trials Centre, University of Sydney, Australia.

“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.”

Delaying clamping the umbilical cord is thought to help ease infants’ transition to breathing after birth. This is because the practice allows oxygen-rich blood to continue to flow from the placenta to the baby while the lungs fill with air.

However, until recently, clinicians generally cut the cord of preterm babies immediately so urgent medical care could be given. Uncertainties have led to different recommendations in national and international guidelines.

The first paper included data from 6,094 infants and compared five alternative cord-clamping strategies’ effects on risk of death before discharge from hospital. It found that waiting at least two minutes before clamping the cord reduced the risk of death in premature babies by two thirds (odds ratio of 0.31).

“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,” says Dr Sol Libesman, lead statistician for this study and research fellow at the NHMRC Clinical Trials Centre.

“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 second paper included data on 6,367 infants from 48 trials and also found that deferred cord clamping (ranging from 30 seconds to 180 seconds) likely reducing the risk of death in premature babies by a third (an odds ratio of 0.68) compared to immediate clamping.

The researchers highlight that more research is still needed for situations in which babies require immediate resuscitation or in low-income setting with limited medical resources.

“We need further research into how to best provide immediate care to the sickest premature babies while the cord is intact. Even for healthier premature babies, it may seem counter-intuitive to some doctors to defer cord clamping when the baby requires care, but with appropriate training and equipment, along with a full team approach involving midwives, doctors and parents, it is possible to successfully defer cord clamping while ensuring the baby is warm, breathing, and cared for,” says Seidler.