What teratogen causes severe limb deficiencies?

The teratogen that causes severe limb deficiency is thalidomide. Thalidomide is a drug prescribed in the late 1950s as a sedative and morning sickness remedy. It is known to cause severe birth defects, including limb deficiencies, heart defects, and facial abnormalities. Phocomelia, a rare condition in which babies are born with missing or malformed limbs, is one of the most notable limb deficiencies caused by thalidomide.