Objectives: To examine associations between mothers’ use of prenatal folic acid supplements and risk of severe language delay in their children at age 3 years.
Methods: In the prospective Norwegian Mother and Child Study, pregnant women were recruited from 1999-2008. We used data on children born before 2008 whose mothers returned the age 3 follow-up questionnaire by June 16th 2010. The exposure was maternal use of folic acid supplements within the interval from 4 weeks prior to conception to 8 weeks after. The outcome was severe language delay at age 3 based on maternal report. Children with minimal expressive language (only one-word or unintelligible utterances) were rated as having severe language delay. Relative risks were approximated by estimating odds ratios [OR] with 95% confidence intervals [CI] in a logistic regression analysis.
Results: Among 38 954 children, 204 (0.5%) had severe language delay. Children whose mothers took no dietary supplements in the specified exposure interval were the reference group, (n=9052 [24.0%], with severe language delay in 81 [0.9%). Adjusted odds ratios for three patterns of exposure to maternal dietary supplements were: (1) other supplements, but no folic acid (n=2480 [6.6%)], with severe language delay in 22 children [0.9%]; OR, 1.04; 95% CI, 0.62 to 1.74); (2) folic acid only (n=7127 [18.9%], with severe language delay in 28 children [0.4%]; OR, 0.55; 95% CI, 0.35 to 0.86); and (3) folic acid in combination with other supplements (n=19,005 [50.5%], with severe language delay in 73 children [0.4%]; OR, 0.55; 95% CI, 0.39 to 0.78).
Conclusions: Among this Norwegian cohort of mothers and children, maternal use of folic acid supplements in early pregnancy was associated with a reduced risk of severe language delay in children at age 3 years.
See more of: Epidemiology
See more of: Prevalence, Risk factors & Intervention