Anne-Lise Bjørke-Monsen

Background: Although some antiseizure medications (ASMs) are teratogenic, most people with epilepsy need treatment in pregnancy. The risk of ASM fetotoxicity may be mitigated with folic acid. High-dose folic acid supplementation has traditionally been recommended before and during gestation despite little evidence of efficacy and safety for this patient group. Several studies have investigated the potential benefits and risks of folic acid supplements.Objective: To provide an updated overview of the risks, benefits, and rationale for use of folic acid supplementation in relation to pregnant people of childbearing age using ASM.Materials and methods: This is a narrative review based on an unstructured literature search of PubMed. We also scrutinized neurological and obstetrical guidelines.Results: Antiseizure medication can decrease folate concentrations. In children exposed to ASM prenatally, those born to persons using folic acid supplements periconceptionally had lower risk of adverse neurodevelopment and preterm birth. It remains unclear whether the risk for congenital malformations can be equally alleviated. In studies of the general population, high plasma folate concentrations and/or high-dose folic acid supplements were associated with adverse neurodevelopmental outcomes. This has not been seen in children of mothers with epilepsy. However, an increased cancer risk has been found in children of mothers with epilepsy using high-dose folic acid supplements in pregnancy.Conclusion: The optimal folic acid dose is not clear for persons of childbearing potential with epilepsy using ASM. Both low and excess folate status during pregnancy have been associated with adverse neurodevelopment. We propose an individual folic acid supplement dose that should be titrated based on maternal plasma folate concentrations during pregnancy.

Background: The sensitivity of newborn screening (NBS) in detecting infants that later develop symptomatic vitamin B12 deficiency is unknown. We evaluated the predictive value using NBS algorithms in detecting infants that later were clinically diagnosed with symptomatic B12 deficiency. Furthermore, we investigated whether being born in a hospital using nitrous oxide (N₂O) as pain relief in labor may have had an impact on total homocysteine at NBS. Methods: We retrospectively retrieved NBS data and analyzed total homocysteine, methylmalonic acid and methyl citrate on stored NBS dried blood spots (DBS) of 70 infants diagnosed with symptomatic B12 deficiency and compared them to 646 matched and 434 unmatched DBS controls to evaluate the Austrian and Heidelberg B12 NBS algorithms. Results: The sensitivity of NBS in detecting infants later diagnosed with symptomatic B12 deficiency at median age 10.9 weeks was ≤10%. Total homocysteine was higher in DBS for the unmatched controls who were born in hospitals providing N₂O compared to in hospitals not providing N₂O, with median total homocysteine 4.0 µmol/L compared to 3.5 µmol/L (n = 434, 95% CI 0.04–0.87, p = 0.03). Conclusion: NBS algorithms were unable to identify most infants diagnosed with symptomatic B12 deficiency after the neonatal period. Being born in hospitals providing N₂O may impact total homocysteine at NBS.