This population-based cohort study (N = 3,209) assessed the association of maternal folate status during pregnancy with child emotional and behavioral problems at age three years. It also examined whether any association between folate status and child problems is a consequence of maternal folic acid supplement use or a variation in maternal MTHFR genotype (mothers of European descent were genotyped for the MTHFR 677 C→T polymorphism). Children of mothers with prenatal folate deficiency were at higher risk of emotional problems (OR 1.57; 95% CI 1.03-2.38) but not behavioral problems (OR 1.00; 95% CI 0.64-1.56) after adjustment for confounders. A higher risk of emotional problems was also found in children whose mothers started using folic acid supplements late or did not use supplements at all (OR 1.45; 95% CI 1.14-1.84) compared to children whose mothers started periconceptionally. However, low plasma folate concentrations only partly explained this association (OR 1.38; 95% CI 1.08-1.78). Although related to plasma folate concentrations, maternal MTHFR genotype did not explain the association of folate status with offspring emotional problems. Therefore, low maternal folate status during early pregnancy is associated with a higher risk of childhood emotional problems. Am J Clin Nutr. 2012 May 9. PMID: 22572645
