Children of mothers who continued folic acid supplementation throughout pregnancy scored significantly higher on specific cognitive tests at age 3 and 7, compared to children of mothers who took a placebo, report scientists from Ulster University in Northern Ireland, University College Dublin and Trinity University in the Republic of Ireland.
“As a follow-up study of children whose mothers had participated in an RCT during trimesters 2 and 3 of pregnancy, the FASSTT Offspring study provides the first randomized trial evidence that continuing FA [folic acid] supplementation throughout pregnancy, well beyond the early period known to be protective against NTDs, can influence cognitive development of the child up to 7 years of age,” they wrote in the journal BMC Medicine.
Folic acid benefits
An overwhelming body of evidence links has linked folate deficiency in early pregnancy to increased risk of neural tube defects (NTD) - most commonly spina bifida and anencephaly - in infants.
This connection led to the 1998 introduction of public health measures in the US and Canada, where all grain products are fortified with folic acid - the synthetic, bioavailable form of folate.
Currently, 84 countries fortify industrially milled wheat flour, maize products and/or rice with folic acid, according to data from the Food Fortification Initiative (FFI). A meta-analysis published in 2010 showed an overall 46% reduction in neural tube defects such as spina bifida and anencephaly in countries where wheat flour was fortified with this B vitamin.
The US Centers for Disease Control and Prevention (CDC) has listed the prevention of neural tube defects through flour fortification amongst its list of 10 great health achievements in the US.
The new study indicated that extending the period of folic acid supplementation beyond the first trimester may also confer additional cognitive benefits to the child.
Study details
The new study assessed data from children whose mothers took part in the Folic Acid Supplementation during the Second and Third Trimesters (FASSTT) trial in pregnancy. From an initial 119 mother-child pairs, the researchers had access to data from 70 children at age seven, and 39 at age three.
The results showed that at age seven, children of mothers who received folic acid supplements (400 micrograms per day) had significantly higher scores in word reasoning, compared to children of mothers who received placebo).
In addition, the folic acid children scored higher for cognition as three-year olds, compared to the placebo group.
At both age groups, more folic acid children had above average scores on the Bayley’s Scale of Infant and Toddler Development (BSITD-III) and then later on the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III)
“The wider public health relevance of our findings is suggested by the supporting data from comparison of the cognitive performance of the FASSTT Offspring Trial participants with that of a nationally representative sample of British children of the same age,” explained the researchers. “When compared with British children at age 7 years, WPPSI-III scores for verbal IQ, general language, and full-scale IQ were each higher in children from FA treated mothers.”
The researchers concluded: “The results show that there are benefits for the child of continuing maternal use of [folic acid] throughout pregnancy, whereas current recommendations in most countries worldwide advise mothers to take [folic acid] supplements from before conceiving until the end of the 12th gestational week only.
“If confirmed by further randomized trials in pregnancy with follow-up in childhood, these findings could have important impacts in informing future policy and practice in relation to [folic acid] recommendations in pregnancy.”
Source: BMC Medicine
Volume 17, Article number: 196, doi: 10.1186/s12916-019-1432-4
“Effect of continued folic acid supplementation beyond the first trimester of pregnancy on cognitive performance in the child: a follow-up study from a randomized controlled trial (FASSTT Offspring Trial)”
Authors: H. McNulty, et al.