High-dose folic acid during pregnancy increases cancer risk in children of mothers with epilepsy

October 2022 Medical Research Nalinee Pandey
Vitamins supplements as a capsule with fruit vegetables nuts and beans inside a nutrient pill as a natural medicine health treatment with 3D illustration elements.

Researchers have found that mothers with epilepsy who are taking high-dose folic acid supplements are at increased risk of cancer during pregnancy. These findings were recently published in the journal JAMA Neurology.

Women with epilepsy are recommended to take high doses of folic acid during pregnancy. Folic acid supplements prevent congenital malformations, but whether exposure to these high doses can increase cancer risk in developing children remains unknown. A Scandinavian study has addressed these questions using the nationwide population register of Scandinavian countries. 

Study design

From 1997 to 2017, the SCAN-AED project conducted an observational cohort study using population registers out of Denmark, Sweden, and Norway. The study included  3,379,171 children, of which 27,784 were born to mothers with epilepsy, and 5,933 mothers with epilepsy who had received a high-dose of folic acid.

Main findings

Children born to mothers that were diagnosed with epilepsy and were exposed to high doses of folic acid (mean dose, 4.3 mg) had an increased risk of developing cancer (1.4%, 95% CI, 0.5%-3.6%) as compared to the unexposed group (0.6%, 95% CI, 0.3%-1.1%). Notably, there was no increase in cancer risk for the children of mothers without epilepsy that were exposed to high-dose folic acid. Also, the use of antiseizure medication was not associated with increased cancer risk in children born to mothers with epilepsy.


These findings demonstrate a link between folic acid doses and cancer risk in children born to mothers with epilepsy. Therefore, it is essential to identify the optimal folic acid intake for pregnant women with epilepsy to reduce the cancer risk of their children.


Vegrim HM, Dreier JW, Alvestad S, et al. Cancer Risk in Children of Mothers With Epilepsy and High-Dose Folic Acid Use During Pregnancy. JAMA Neurology 2022;e222977.