Author Affiliations: School of Nursing (Ms Merry) (email@example.com) and Division of General Internal Medicine (Dr Chen), McGill University, Montreal, Quebec, Canada; and Department of Surgery, University of Western Ontario, London, Canada (Dr Martin).
To the Editor: In their study on newer-generation antiepileptic drugs, Ms Mølgaard-Nielsen and Dr Hviid concluded that first trimester exposure to newer-generation antiepileptic drugs was not associated with an increased risk of major birth defects when compared with no exposure.1 A slightly different conclusion was stated in the final section of their article: “The use of lamotrigine and oxcarbazepine during the first trimester was not associated with moderate or greater risks of major birth defects like the older-generation antiepileptic drugs, but our study cannot exclude a minor excess in risk of major birth defects. . . . ” The authors acknowledged that they had an inadequate sample size to draw firm conclusions regarding the individual effects of topiramate, gabapentin, and levetiracetam. However, we believe the study was also underpowered to detect an increased risk in major birth defects overall and for lamotrigine and oxcarbazepine. Therefore, definitive conclusions about whether newer-generation antiepileptic drugs are associated with an increased risk of major birth defects seem difficult to make based on this study.
Merry L, Martin KL, Chen T. Major Birth Defects After Exposure to Newer-Generation Antiepileptic Drugs. JAMA. 2011;306(8):826-827. doi:10.1001/jama.2011.1184