Birth weight and other risk factors for acute leukemia in the Jerusalem Perinatal Study cohort.

OBJECTIVES

To assess the effect of birth weight of children and their siblings and other perinatal/parental factors on the risk of acute leukemia.

METHODS

We linked data from the Jerusalem Perinatal Study, a population-based research cohort (n = 88,829) of offspring born 1964 to 1976, with Israel's Cancer Registry. Risk factors for acute leukemia were assessed using univariate and multivariate proportional hazards models.

RESULTS

Leukemias developed in 65 individuals [24 acute myeloid leukemias (AML) and 41 acute lymphoblastic leukemias (ALL)]. A positive linear relation was found between gender-adjusted birth weight and all leukemias [hazard ratio (HR) 1.85, 95% confidence interval (95% CI) 1.1-3.0] and AML (HR 2.9, 95% CI 1.3-6.4). The association between birth weight and AML was especially notable among infants (HR 8.14, 95% CI 1.8-38.9 for age 0 to 1 year) but was also observed among subjects ages >14 years at diagnosis. The relation was particularly strong among females (P = 0.001). Other risk factors for AML risk on univariate analysis were maternal origin, socioeconomic status, birth weight of sibling > 3,500 g, and family size. On multivariate analysis, only birth weight retained borderline significance (adjusted HR 2.38 per kg, 95% CI 1.0-5.7). Significant predictors for ALL in both univariate and multivariate analyses were male sex (adjusted HR 1.92, 95% CI 1.0-3.7) and birth weight categories > or = 3,000 g introduced into the model as nonlinear terms.

CONCLUSION

Birth weight is associated with an increased risk of acute leukemia in infants, children, and young adults. Perinatal factors play a role in the development of childhood leukemias, but the patterns of association vary by leukemia type.