Respiratory infections and STIs in pregnancy linked to offspring's risk of leukemia

Children whose mothers had flu, pneumonia, or a sexually transmitted disease during pregnancy may have a greater risk of childhood leukemia than children of healthy mothers, according to the results of a study published in the Jan. 1 issue of the American Journal of Epidemiology.

Marilyn L. Kwan, PhD, of Kaiser Permanente in Oakland, Calif., and colleagues compared information about mothers' drug use and disease during pregnancy and breastfeeding among 365 children diagnosed with leukemia before age 15 and matched controls.

The researchers found that children whose mothers had influenza or pneumonia while pregnant had a significantly higher risk of acute lymphoblastic leukemia (OR, 1.89) than those with healthy mothers; the risk was not significant for common acute lymphoblastic leukemia.

"Observing an increased risk of leukemia in children of mothers reporting a history of influenza/pneumonia and sexually transmitted disease around the time of pregnancy suggests that maternal infection might contribute to the etiology of leukemia," the authors write. "Furthermore, maternal iron supplement use may be protective against childhood leukemia."

Kwan ML, Metayer C, Crouse V, et al. Maternal illness and drug/medication use during the period surrounding pregnancy and risk of childhood leukemia among offspring. Am J Epidemiol. 2006;165:27-35.