Maternal alcohol consumption during pregnancy and risk of childhood leukemia: systematic review and meta-analysis.

BACKGROUND Leukemia is the most frequently occurring cancer in children. Although its etiology is largely unknown, leukemia is believed to result from an interaction between genetic and environmental factors. Among different potential risk factors, the possible role of maternal alcohol consumption during pregnancy has been questioned. METHODS To assess the association between maternal alcohol consumption during pregnancy and childhood leukemia, a systematic review and meta-analysis of published studies was done. RESULTS Twenty-one case-control studies were included in categorical and dose-response meta-analyses. No cohort study was identified. Analyses were conducted by type of leukemia, children's age at diagnosis, and type of alcoholic beverage and trimester of pregnancy at alcohol use. Alcohol intake during pregnancy (yes versus no) was statistically significantly associated with childhood acute myeloid leukemia (AML) [odds ratio (OR), 1.56; 95% confidence interval (CI), 1.13-2.15] but not with acute lymphoblastic leukemia (OR, 1.10; 95% CI, 0.93-1.29). Heterogeneity between studies was observed. The OR of AML for an increase of a drink per week was 1.24 (95% CI, 0.94-1.64). The association of alcohol intake during pregnancy with AML was observed for cancers diagnosed at age 0 to 4 years (OR, 2.68; 95% CI, 1.85-3.89) in five studies without heterogeneity (I2<or=0.1%). CONCLUSIONS The results of case-control studies indicate that maternal alcohol consumption during pregnancy is associated with a significantly increased risk of AML in young children. IMPACT Avoidance of maternal alcohol drinking during pregnancy might contribute to a decrease in the risk of childhood AML.