The effect of maternal unmetabolized folic acid on allergic disease in the infant
BACKGROUND: The combination of mandatory fortifications of foods and prenatal folic acid supplementation has resulted in increased maternal blood folate levels resulting in an increase in circulating unmetabolized folic acid (UMFA). There is no proven benefit of prenatal folic acid supplementation beyond fetal neural tube closure (~28 days) and there is growing concern that UMFA may be the mediator by which excess folic acid is causing harm, most notably an increased risk of childhood allergic disease.
GAP: The association between maternal UMFA and incidence of allergic disease in the infant is unknown.
HYPOTHESIS: Infants born to women with higher levels of plasma UMFA in late gestation will have an increased incidence of sensitization and allergic disease symptoms at 12 months of age than those born to women with lower levels of UMFA.
METHODS: Plasma UMFA collected in late gestation from pregnant women who participated a RCT in WA in 2005 will be examined in relation to infant allergic disease outcomes including sensitization, eczema and food allergy at 12 months of age (n=484). We will also measure contemporary maternal folate status from samples collected from South Australian pregnant women (n=616) participating in our large trial of omega-3 supplementation to prevent preterm birth.
IMPACT: Taking folic acid beyond early pregnancy confers no proven benefit and may potentially be harmful. These analyses will provide pilot data to determine optimal late gestation folate status for the prevention of allergic disease in the infant.
Optional/Additional Comments: These data will be utilized to apply for major funding to conduct a large randomized controlled trial to explore the effect of maternal folate and UMFA status and allergic disease in the offspring.