High birth weight as an important risk factor for infant leukemia

In this paper, we compared the birth weight distribution among 201 infant leukaemia (IL) cases with that of 440 noncancer controls enrolled in Brazil in 1999-2005. Compared with the general population and the stratum 2500-2999 g as reference, IL cases weighing 3000-3999 g presented an odds ratio (OR) of 1.68 (95% CI: 1.03-2.76), and those of 4000 g or more, an OR of 2.28 (95% CI: 1.08-4.75), P-trend < 0.01. Using hospital-based controls, the OR for 4000 g or more, compared to 2500-2999 g, was 1.30 (95% CI: 1.02-1.43) after adjusting for confounders (gender, income, maternal age, pesticide and hormonal exposure during pregnancy). The results suggest that high birth weight is associated with increased risk of IL.