In a review of 229,101 deliveries to Michigan Medicaid patients, 1034 first-trimester exposures to terfenadine were recorded and 2042 exposures anytime during pregnancy. A total of 51 birth defects were reported with first-trimester exposure (44 expected) and included (observed/expected) 13/10 cardiovascular defects, 2 oral clefts, 12/2 polydactyly, and 3/1 limb reduction defects. A significant relative risk exists for polydactylies (5.4) and limb reduction defects. (written communication, Franz Rosa, MD, Food and Drug Administration, 1994)

Terfenadine has been assigned to pregnancy category C. Animal studies have failed to reveal evidence of teratogenicity. There are no controlled data in human pregnancy. Terfenadine should only be given during pregnancy when there are no alternatives and benefit outweighs the risk.

See references