THURSDAY, July 11 (HealthDay News) -- Doctors may be clamping umbilical cords too soon after a baby's birth, according to a new study.
Doctors routinely clamp and sever the umbilical cord less than a minute after birth, a practice believed to lower the risk of severe bleeding in the mother.
But this new study found that delaying clamping for at least a minute after birth allows more time for blood to move from the placenta and helps boost iron stores and hemoglobin levels in newborns, without increasing the risks to mothers, The New York Times reported Thursday.
Compared with babies who had early clamping, those who had delayed clamping had higher hemoglobin levels 24 to 48 hours after birth and were less likely to be iron deficient three to six months after birth, the Times reported.
Later clamping did not increase the mothers' risk of severe bleeding after birth, blood loss or reduced hemoglobin levels, according to the study published Wednesday in The Cochrane Database of Systematic Reviews.
The findings are based on an analysis of data from 15 previous studies involving nearly 4,000 mother-and-infant pairs.
"In terms of a healthy start for a baby, one thing we can do by delaying cord clamping is boost their iron stores for a little bit longer," said review lead author Susan McDonald, a professor of midwifery at La Trobe University in Melbourne, Australia, the Times reported.
The timing of cord clamping has been controversial for years. The review findings appear to bolster the case for later clamping, a U.S. expert said.
"It's a persuasive finding," Dr. Jeffrey Ecker, chair of the committee on obstetrics practice for the American College of Obstetricians and Gynecologists, told the Times. "It's tough not to think that delayed cord clamping, including better iron stores and more hemoglobin, is a good thing."
"I suspect we'll have more and more delayed cord clamping," Ecker added.
Dr. Eileen Hutton, a midwife who teaches obstetrics at McMaster University in Ontario, Canada, and published a review on cord clamping, said the implications of early clamping are significant. "We are talking about depriving babies of 30 to 40 percent of their blood at birth -- and just because we've learned a practice that's bad," Hutton said.
The World Health Organization recommends clamping of the cord after one to three minutes because it "improves the iron status of the infant," the Times reported. In some cases, delayed clamping can lead to jaundice in infants due to liver trouble or an excessive loss of red blood cells. Because of this, the WHO recommends that access to therapy for jaundice be taken into consideration.
Few women who had Caesarean sections were included in the current study, and that concerns one expert.
"We don't have enough information on the effects of delayed cord clamping for someone undergoing a Caesarean delivery in terms of postpartum hemorrhage," Dr. Cynthia Gyamfi-Bannerman, medical director of the perinatal clinic at Columbia University in New York City, told the Times. In certain cases, "there's an increased risk of postpartum hemorrhage," she said.
There is some belief that improved iron stores at birth could have long-term neurological benefits for children, and studies are under way to test that theory.
The U.S. National Library of Medicine talks about umbilical cord care.