Maternal Folate Intake and Risk of Childhood Brain and Spinal Cord Tumors: A Systematic Review and Meta-Analysis.

BACKGROUND: Many epidemiological studies have investigated the effect of maternal diet and prenatal multivitamin supplementation on pediatric cancer risk. Childhood brain and spinal cord tumors (CBSCT) have been attributed to different possible risk factors.

METHODS: We conducted a systematic review and meta-analysis on maternal folate intake before and during pregnancy and the risk of CBSCT. We systematically reviewed publications obtained by searching the Insitute for Scientific Information Web of Knowledge and PubMed literature databases. We extracted the risk estimate of the highest and the lowest reported categories of intake from each study and conducted a meta-analysis using a random-effects model.

RESULTS: The results of the pooled analysis of all 10 studies, 1 cohort and 9 case-control studies, indicated that maternal folate intake was inversely associated with CBSCT risk (OR 0.77; 95% CI 0.67-0.88, p < 0.001; I2 = 51.22%, p = 0.001). Separate analyses on the basis of the source of folate (folic acid supplementation, dietary folate) and in relation to the timing of exposure (before pregnancy, during pregnancy) found that folic acid supplementation was associated with an approximately 23% reduction in -CBSCT risk (OR 0.77, 95% CI 0.66-0.90, p = 0.001; I2 = 53.18%, p = 0.001) and consumption during pregnancy was associated with an approximately 20% reduction in CBSCT risk (OR 0.80, 95% CI 0.67-0.97, p = 0.020; I2 = 62.48%, p < 0·001).

CONCLUSIONS: Maternal consumption of folic acid is associated with a reduced risk of CBSCT. Further investigations are necessary to increase the reliability of the results and estimate the relationship between dose-response and the best outcome.