Waiting two minutes or more to clamp the umbilical cord of a premature baby immediately after birth may reduce the risk of death, compared with clamping the umbilical cord immediately, or waiting a shorter time before doing so. Delayed clamping can reduce the risk of infant death by more than half compared to immediate clamping.
The new findings, published today in two companion papers The Lancetexamined clinical trial data and outcomes of thousands of preterm infants who underwent cord clamping immediately after birth compared with those whose cord clamping was delayed.
Delaying umbilical cord clamping allows blood to flow from the placenta to the baby while the baby’s lungs fill with air. This is thought to help ease the transition to baby breathing.
Worldwide, approximately 13 million babies are born prematurely each year and, tragically, close to 1 million die shortly after birth. Our new findings are the best evidence to date that waiting to clip the umbilical cord may help save the lives of some premature babies.”
Dr Anna Lane Seidler, First Author, NHMRC Clinical Trials Centre, University of Sydney
“We are already working with international guideline developers to ensure that these findings are reflected in updated guidelines and clinical practice in the near future.”
Delayed cord clamping is now the recommended routine practice for babies born at full term. However, while previous research, including a trial led by the University of Sydney, showed potential benefits for preterm infants, best practice for this vulnerable group was uncertain. Until recently, doctors usually cut the cord of preterm babies immediately to provide emergency medical care.
This uncertainty has led to different recommendations in national and international guidelines.
For example, for babies not requiring resuscitation at birth, the Australian and New Zealand Committee on Resuscitation (ANZCOR) recommends delaying cord clamping for at least 30 seconds.
The World Health Organization and the UK’s National Institute for Health and Care Excellence (NICE) recommend delayed umbilical cord clamping (no earlier than 1 minute after birth) to improve maternal and infant health and nutrition.
Preterm infants require resuscitation, WHO recommends immediate clamping, ANZCOR makes no recommendation due to insufficient evidence.
The largest delayed cord clamping dataset to date
The studies are the result of a large global effort on umbilical cord management (iCOMP collaboration) among more than 100 international researchers, who shared their original data with Dr. Seidler and his team for analysis, including the large APTS trial led by the university. of sydney
It has created one of the largest databases in this research field with over 60 studies and over 9000 children.
The first paper used data from 3,292 children in 20 studies Delayed umbilical cord clamping for 30 seconds or more after birth was found to reduce the risk of death in premature babies by a third compared to those who had the umbilical cord clamped immediately after birth.
In a subgroup of premature babies in which babies were born before 32 weeks of gestation, 44.9 percent of babies with immediate cord clamping experienced hypothermia after birth, compared with 51.2 percent of those with delayed clamping. The mean temperature difference between the delayed clamping group and the immediate clamping group was -0.13 °C.
“Our findings highlight that special care should be taken to keep premature babies warm when postponing umbilical cord clamping. This can be done by drying the baby and wrapping the cord and then placing the dry baby directly under the mother’s bare chest. A blanket, or bedside warming trolley. using,” said senior study author Professor Lisa Askey, from the NHMRC Clinical Trials Centre.
The second paper analyzed data from 47 clinical trials, involving 6,094 infants, and found that waiting at least two minutes before clamping a premature baby’s cord may have a lower risk of death than waiting less time to clamp the cord.
When comparing different times, waiting two or more minutes to clamp the cord was 91 percent more likely to be the best treatment to prevent death soon after birth.
Immediate clamping was very unlikely (<1%) to be the best treatment to prevent death.
“Until recently, it was standard practice to clamp the umbilical cord immediately after birth in premature babies so they could be dried, wrapped and easily resuscitated if needed,” said Dr Sol Liebsman, the study’s lead statistician and research fellow at the NHMRC Clinical Trials Centre.
“Our study shows that there is no longer a case for immediate clamping and instead, the currently available evidence suggests that delaying cord clamping for at least two minutes is probably the best cord management strategy to reduce the risk of death in premature infants after birth. “
However, the researchers highlight situations where more research on cord clamping is needed. This includes when children require immediate resuscitation, unless the hospital cord is intact or able to provide safe basic respiratory support in low-income settings with limited medical resources.
“We need more research on how to best care for the sickest preterm babies while the cord is intact. Even for healthy preterm babies, some doctors may find it counterintuitive to postpone cord clamping if the baby needs care, but with appropriate training and equipment, midwives, With a whole team approach involving doctors and parents, it is possible to successfully suspend cord clamping while ensuring the baby is warm, breathing and cared for,” said Dr. Seidler.