Delaying clamping the umbilical cord at birth by roughly two minutes can give newborns a health boost that carries through the early months of their lives, a new study suggests.
Late clamping, as it is called, allows more blood from the cord and the placenta to flow into the infant, raising iron levels and decreasing the risk of anemia in the first weeks and months of life, McMaster University researchers suggested in the article, published Wednesday in the Journal of the American Medical Association.
"Although this is of particular importance for developing countries in which anemia during infancy and childhood is prevalent, it is likely to have an important impact on all newborns, regardless of birth setting," the authors said.
But late clamping isn't widely practised in developed countries and this paper may not change that fact, according to an editorial in the same issue of the journal.
"A stronger and universal endorsement of delayed clamping will require a well-designed and preferably multi-centre (to factor in centre effects) randomized controlled trial with a sample size that is powered to address both benefits and potential adverse effects of this intervention," wrote Dr. William Oh, of Women and Infants Hospital in Providence, RI.
That's because the article by the McMaster team isn't an account of a clinical trial, it is an analysis of a series of 15 studies looking at the benefits and risks of late clamping.
Lead author Eileen Hutton, assistant dean of midwifery at the university, said the jury has been out on early versus late clamping.
Some doctors believe in clamping the umbilical cord virtually immediately, to help in the delivery of the placenta and to reduce the risk newborns will develop a condition called polycythemia. The opposite of anemia, it occurs when the blood is too rich with red blood cells and the blood is too thick to flow well.
At the other end of the spectrum, proponents of late clamping believe its benefits outweigh that risk.
By pooling the data from the 15 mainly small studies she could find on the subject, Ms. Hutton and co-author Eman Hassan concluded the evidence shows statistically significant lowering of anemia rates in babies who were clamped late, but no real increased risk of serious polycythemia in those same babies.
"And the significance is not just at the time the baby's born, it lasts quite a long period of time," she said from Hamilton.
"The iron stores were increased out to six months of age. Basically you can imagine it's giving your baby a better start."