Table 2.

Risk of major congenital malformations with exposure to a specific antiepileptic drug monotherapy during the first trimester as reported by the North American AED Pregnancy Registry, 1997–2011

Antiepileptic Drug Monotherapy	Major Congenital Malformations, No. (%) and 95% Cl
Unexposed (n = 442)	5 (1.1), 0.37–2.6
Lamotrigine (n = l562)	31 (2.0), 1.4–2.8
Carbamazepine (n = l033)	31 (3.0), 2.1–4.2
Phenytoin (n = 416)	12 (2.9), 1.5–5.0
Levetiracetam (n = 450)	11 (2.4), 1.2–4.3
Topiramate (n = 359)	15 (4.2), 2.4–6.8
Valproate (n = 323)	30 (9.3), 6.4–13.0
Phenobarbital (n = 199)	11 (5.5), 2.8–9.7
Oxcarbazepine (n = 182)	4 (2.2), 0.6–5.5
Gabapentin (n = 145)	1 (0.7), 0.02–3.8
Zonisamide (n = 90)	0 (0), 0.0–3.3
Clonazepam (n = 64)	2 (3.1), 0.4–10.8