SOURCES: Ola Andersson, M.D., Ph.D., consultant in pediatrics and neonatology, and researcher, department of women's and children's health, Uppsala University, Uppsala, Sweden; Heike Rabe, M.D., Ph.D., senior clinical lecturer and honorary consultant neonatologist, Brighton & Sussex Medical School, academic department of pediatrics, Royal Alexandra Children's Hospital, Brighton, U.K.; May 26, 2015, JAMA Pediatrics, online
TUESDAY, May 26, 2015 (HealthDay News) -- Waiting about three minutes to clamp the umbilical cord following a baby's delivery may help improve children's fine-motor and social skills at age 4 years, new Swedish research suggests.
The researchers said postponing the clamping of the cord allows continued flow of fetal blood from the placenta to the newborn. This, in turn, appears to be tied to improved infant iron levels by the critical 4- to 6-month mark, which may help prevent certain developmental problems, the study authors suggested.
"During the delayed clamping, the child receives half a cup of extra blood, which contains a lot of iron, and can prevent iron deficiency," said study lead author Dr. Ola Andersson, a consultant in pediatrics and neonatology, and a researcher in the department of women's and children's health at Uppsala University in Uppsala, Sweden.
"In our study, a psychologist performed tests and the results showed that children's intelligence was the same, but those who had delayed clamping had better fine-motor skills and a tendency toward better social skills," he said.
"Boys had the most benefit from delayed cord clamping. We believe it's because boys are more likely to have iron deficiency, and therefore have a greater advantage of receiving the extra blood transfusion," he added.
However, the researchers noted that the study has limitations and can't definitively show that delayed cord clamping is what affected the children's development.
The study findings were published in the May 26 online edition of JAMA Pediatrics.
Iron deficiency is the most common nutritional deficiency in the United States, according to the U.S. Centers for Disease Control and Prevention. Among infants, it is known to raise the risk for developmental delays in both motor control and mental skills, the CDC said.
Andersson said that nearly 16 percent of American infants between the ages of 1 and 2 years have iron deficiency. He said that figure can rise dramatically in some developing countries.
For the new study, the impact of cord-clamp timing on childhood development was assessed among more than 260 Swedish children. The infants were all delivered at a single Swedish hospital.
The babies were randomly placed into one of two groups. One group had their cord clamped at the standard time -- about 10 seconds after birth. For the other group, a minimum cord-clamping delay of three minutes was performed.
When the children were 4 years old, psychologists tested their development.
The researchers found that boys in the delayed-clamping group demonstrated better motor function -- such as gripping a pencil -- and more pro-social behavior, compared with those whose cord had been clamped right after delivery.
No differences, however, were seen in the girls, regardless of cord-clamp timing. No differences were observed among either boys or girls with respect to IQ levels, the study found.
Are there any risks involved in delaying the cord-clamping?
"Some older studies did show that newborns could be more jaundiced if subjected to delayed clamping," acknowledged Andersson. "[But] our study -- as well as some other recent studies -- has not been able to demonstrate this."
Dr. Heike Rabe, a senior clinical lecturer and honorary consultant neonatologist with Brighton & Sussex Medical School's academic department of pediatrics at the Royal Alexandra Children's Hospital in Brighton, England, co-authored an editorial accompanying the study. She said, "There is growing evidence from a number of studies that all infants -- born at term and those born too early -- do benefit from receiving extra blood from the placenta at birth."
Rabe said many maternity departments in the United States have already incorporated cord-clamping delays into their protocol. And the interest in doing so appears to be growing.
But, Rabe added, the benefits of such a delay "is particularly important for babies born in developing countries, as the better iron levels [also may] lead to less infections in the first months of life."
There's more on iron deficiency at the U.S. Centers for Disease Control and Prevention.