Work

Prenatal vitamins, folic acid intake, and folate metabolism gene variant in association with risk for autism spectrum disorder in the Early Autism Risk Longitudinal Investigation (EARLI) pregnancy cohort.

Year: 2019

Type: article

Abstract: TPS 771: Diet and lifestyle, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: Folic acid is critical to fetal neurodevelopment. Bioavailable folate is affected by both folic acid intake and folate processing genetics. We tested whether maternal prenatal vitamin use or folic acid intake during the first month of pregnancy was associated with autism spectrum disorder (ASD) risk, and whether this association differed by maternal folate metabolism genotype. Methods: The Early Autism Risk Longitudinal Investigation is an enriched risk pregnancy cohort. Supplement use was reported prospectively by month during pregnancy. Total folic acid intake in pregnancy month one was calculated from supplement use (prenatal vitamins, multivitamins, folic acid). Clinical ASD diagnosis was made at 36-months (37 cases, 139 controls). Using logistic regression, we examined associations of maternal prenatal vitamin use or maternal folic acid intake (low (<400mcg), adequate (400-1000mcg), and high (>1000mcg)) on child’s ASD diagnosis (n=176 mother-child pairs), adjusting for child’s sex and maternal education. We tested for effect modification by methylene tetrahydrofolate reductase (MTHFR) variant A1298C. Results: Prenatal vitamin use (60.8%), compared to no use, was associated with non-significantly reduced risk of ASD (OR: 0.71, 95%CI: 0.32–1.59), congruent with previous findings in other cohorts. High total folic acid (from any supplement combination, 10.2% of mothers) compared to adequate (46.0%) was not associated with increased odds ASD (OR: 1.49, 95%CI: 0.43–5.16). Low folic total folic acid (43.8%) also was not associated with odds ASD (OR: 0.72, 95%CI: 0.31–1.68). There was no evidence supporting gene-environment interaction, although statistical power was quite limited. Conclusions: We interpret these results of this modestly sized study cautiously. We confirm prenatal vitamin use in pregnancy month one appears protective against ASD. Future work will harmonize with other studies to obtain sufficient MTHFR C677T variant carriers for study and to investigate exposure timing.

Source: Environmental Epidemiology

DOI: 10.1097/01.ee9.0000606096.97574.5d