In most hospital delivery rooms, doctors routinely clamp and sever the umbilical cord less than a minute after an infant’s birth, a practice thought to reduce the risk of maternal haemorrhaging.
But a new analysis has found that delaying clamping for at least a minute after birth, which allows more time for blood to move from the placenta, significantly improves iron stores and haemoglobin levels in newborns and does not increase the risks to mothers.
Doctors usually clamp the umbilical cord in two locations, near the infant’s navel and then farther along the cord, then cut it between the clamps. The timing of the procedure has been controversial for years, and the new analysis adds to a substantial body of evidence suggesting that clamping often occurs too quickly after delivery.
The new paper, published Wednesday in The Cochrane Database of Systematic Reviews, may change minds, though perhaps not immediately. “I suspect we’ll have more and more delayed cord clamping,” said Dr. Jeffrey Ecker, the chair of committee on obstetrics practice for the American College of Obstetricians and Gynecologists.
Newborns with later clamping had higher haemoglobin levels 24 to 48 hours postpartum and were less likely to be iron-deficient three to six months after birth, compared with term babies who had early cord clamping, the analysis found. Birth weight also was significantly higher on average in the late clamping group, in part because babies received more blood from their mothers.
Delayed clamping did not increase the risk of severe postpartum haemorrhage, blood loss or reduced haemoglobin levels in mothers, the analysis found.
“It’s a persuasive finding,” Ecker said. “It’s tough not to think that delayed cord clamping, including better iron stores and more haemoglobin, is a good thing.”
The World Health Organization recommends clamping of the cord after one to three minutes, because it “improves the iron status of the infant.”
Occasionally delayed clamping can lead to jaundice in infants, caused by liver trouble or an excessive loss of red blood cells, and so the WHO advises that access to therapy for jaundice be taken into consideration.
The new analysis did not include many women who had caesarean sections, some experts noted.
“We don’t have enough information on the effects of delayed cord clamping for someone undergoing a caesarean delivery in terms of postpartum haemorrhage,” said Dr. Cynthia Gyamfi-Bannerman, medical director of the perinatal clinic at Columbia University. “Waiting 30 or 60 seconds in a vaginal delivery in a low-risk patient is probably something we could do and wouldn’t have maternal consequences, but in a caesarean delivery, you’re cutting into a pregnant uterus that has a huge amount of blood.” In some scenarios, “there’s an increased risk of postpartum haemorrhage.”