Which medication is known to cause limb shortening as a teratogenic effect if administered during pregnancy?

Thalidomide is recognized for its teratogenic effects, particularly the significant risk of limb shortening when administered during pregnancy. Originally marketed as a sedative and later for treating morning sickness, thalidomide was withdrawn from the market due to its severe side effects. It is associated with phocomelia, a condition that results in the malformation or absence of limbs, caused by its impact on the developing fetus during critical periods of limb development.

In contrast, while other medications listed may have teratogenic effects, they do not specifically cause limb shortening in the same manner as thalidomide. Phenytoin and carbamazepine, for instance, can lead to fetal hydantoin syndrome, which results in craniofacial dysmorphisms and other anomalies, but limb shortening is not a primary concern. Topiramate is also associated with some risk in pregnancy, including orofacial clefts, but again does not lead to limb shortening as a teratogenic outcome. Thus, thalidomide stands out as the medication most commonly linked with this specific teratogenic effect.