TABLE 1.

Congenital birth defects found in association with intrauterine exposure to anti-epileptic medications that inhibit ion channels.

Anti-epileptic medication	Ion channels inhibited	Associated defects
Phenobarbital	GABAA receptors	Cleft lip, cleft palate, reduced head circumference, congenital heart defects, and reduced birth weight
Phenytoin	Voltage-gated Calcium channels	Cleft lip, cleft palate, reduced head circumference, wide mouth, low hair line, congenital heart defects, reduced birth weight, abnormal finger, and toe nails, genitourinary abnormalities
Ethosuximide	Low voltage-gated T type calcium channels	Cleft palate, cleft lip, and limb abnormalities (club foot)
Valproate	Voltage gated calcium channels and HDACs	Cleft lip, cleft palate, flat nasal bridge, broad nasal root, shallow philtrum reduced head circumference, cardiac abnormalities, Neural tube defects, reduced birth weight, limb defects, and genitourinary abnormalities (hypospadia in males)
Topiramate	Voltage gated sodium channels, high voltage gated calcium channels, GABA receptors, glutamate receptors, and HDACs	Cleft lip, cleft palate, and hypospadia