Maternal Hemoglobin Concentration during Pregnancy and Risk of Infant Leukemia.

Little is known about the etiology of childhood leukemia. Elevated birth weight (> 4000 g) is gaining acceptance as a risk factor, particularly for children diagnosed 4000 g (odds ratio (OR) 1.05, 95% confidence interval (CI)=0.55–1.99) Overall, the OR for physiologic anemia of pregnancy and risk of infant leukemia was 0.85 (95%CI=0.53–1.37). The association remained non-significant when cases were divided into acute myeloid leukemia (AML) (n=63) and acute lymphocytic leukemia (ALL) (n=115) with ORs of 0.64 (95%CI=0.32–1.30) and 0.98 (95%CI=0.58–1.66), respectively. The association was also not significant when cases were stratified by MLL gene abnormality status (OR=0.77; 95%CI=0.42–1.40 and OR=0.88; 95%CI=0.45–1.73, for cases with (n=92) and without (n=62) an MLL gene abnormality, respectively). These associations remained non-significant when the data were adjusted for birth weight, maternal race, and birth order. More stringent criteria for anemia also did not modify the results. We found no evidence for an increased risk of infant leukemia in the offspring of mothers with physiologic anemia of pregnancy. This work was supported by NIH R01 CA79940 and the Children’s Cancer Research Fund.