Heavy babies apparently face a heightened risk of one type of childhood leukemia, a Scandinavian study indicates.

Each kilogram increase in birth weight appears to increase the risk of acute lymphoblastic leukemia (ALL) by 26 percent, according to a report in the Journal of the National Cancer Institute. In contrast, high birth weight does not seem to raise the risk of acute myeloid leukemia (AML).

The findings come from a study of 1900 children with ALL, 300 with AML, and a matched comparison group of more than 10,000 healthy children living in Denmark, Sweden, Norway or Iceland.

As noted, the risk of ALL was directly related to birth weight. Moreover, the association was found to be similar across all ages and for both the B-cell and T-cell subtypes of ALL, Dr. Lisa Lyngsie Hjalgrim, from the Statens Serum Institut in Copenhagen, and colleagues report.

However, analysis of sibling data revealed that children who developed ALL did not weigh more than their brothers or sisters at birth, the researchers point out.

“Our results are compatible with the hypothesis that high birth weight modifies the risk of ALL, either through proliferative stress and/or increasing the number of cells at risk of leukemia-associated genetic aberrations,” the investigators conclude.

SOURCE: Journal of the National Cancer Institute, October 20, 2004.