Folic Acid Supplementation Before Pregnancy Halves Birth Defect Risk in Women Taking Antiseizure Medication

A large Nordic register-based study called SCAN-AED conducted by Aarhus University Hospital finds that women with epilepsy taking antiseizure medication can reduce their children's risk of major congenital anomalies by approximately 45% through high-dose folic acid supplementation initiated before pregnancy. The protective effect is critically dependent on timing, as the study found no protective benefit when folic acid supplementation begins after pregnancy onset. The findings highlight the importance of preconception planning for women with epilepsy who require antiseizure medication during pregnancy.

Folic Acid Timing and Protective Effects Against Birth Defects

• ▪Women taking antiseizure medication for epilepsy who initiate high-dose folic acid before pregnancy have around a 45% reduced risk of major congenital anomalies in their children
• ▪Starting folic acid supplementation after pregnancy onset is not associated with any protective effect against major congenital anomalies in women taking antiseizure medication

Study Design and Findings from Nordic Research

• ▪The SCAN-AED study is a large Nordic register-based study involving Aarhus University Hospital

Perspective of Researchers from the SCAN-AED study

• ▪High-dose folic acid supplementation initiated before pregnancy offers significant protection against major congenital anomalies in children of women taking antiseizure medication
• ▪The timing of folic acid supplementation initiation is crucial, with preconception use showing protective benefits that post-conception use does not provide
• ▪The SCAN-AED study represents a large Nordic register-based investigation conducted by Aarhus University Hospital examining folic acid's protective effects