High-dose folic acid supplementation during pregnancy linked to increased cancer risk in children born to women with epilepsy: Study

A 6-month time lag was applied, as cancer is unlikely to develop immediately. Results: With up to 21 years of follow-up, we identified 1 465 785 women who gave birth, including 64 485 (4.4%) exposed to high-dose folic acid. In the exposed group, 755 cancer cases were observed (208 per 100 000 person-years, 95% CI = 193.8–223.5), compared with 18 702 cases in the unexposed group (164 per 100 000 person-years, 95% CI = 161.5–166.2), yielding a 20% increased cancer risk overall (adjusted HR = 1.2, 95% CI = 1.1–1.2). This risk was attenuated after the 6-month lag analysis (adjusted HR = 1.1, 95% CI = 1.04–1.2).

The risk for non-Hodgkin lymphoma was increased in all analyses (n = 28, adjusted HR = 2.0, 95% CI = 1.3–2.9). The association between high-dose folic acid use and overall cancer risk was similar in those with epilepsy regardless of ASM use (adjusted HR = 1.3, 95% CI = 1.0–1.8). High-dose folic acid use was associated with increased overall cancer risk in women who have given birth, with a consistent association with non-Hodgkin lymphoma, including those with epilepsy, regardless of ASM use.

Reference:

Vegrim HM, Dreier JW, Igland J, Alvestad S, Gilhus NE, Gissler M, et al. High-dose folic acid use and cancer risk in women who have given birth: A register-based cohort study. Epilepsia. 2024; 00: 1–14. https://doi.org/10.1111/epi.18146