Thalidomide is a drug that caused severe birth defects in babies born in the 1960s to mothers who took the drug early in pregnancy for morning sickness. The drug was banned due to its significant side effects, but is again being used to treat diseases such as leprosy, AIDS and autoimmune diseases, according to the National Toxicology Program, a branch of the U.S. Department of Health and Human Services. The March of Dimes estimates that even one dose in early pregnancy incurs a risk of defects of 20 to 90 percent (see Reference 1).
Most women took thalidomide in the first three months of pregnancy, when limbs are beginning to form. One of the most devastating complications of thalidomide is phocomelia, the absence of most of the arm, according to the March of Dimes (see Reference 1). Hands are attached like flippers at the shoulder. Radial aplasia, absence of the lower bone in the arms and the thumb, may also occur. Similar defects occur in the legs; most children are affected on both sides of the body, and both the arms and legs can be involved, although arms are more commonly involved than lower limbs.
Ear and eye defects are the second most common defects in babies exposed to thalidomide, according to an article in the Journal of Medical Genetics published in 1999 (see Reference 2). The pinna, the outside of the ear, may be small or completely missing (anotia) and the opening into the ear may be a blind pit. Dermoid cysts (cysts containing cells that can grow into skin, hair or muscle) may occur on the eye surfaces; missing eyes (anophthalmos) or small eyes (microphthalmos) are also known complications of the drug. Cleft lip and palate are also more common in babies exposed to thalidomide. Facial muscles may be weak on one or both sides; facial paralysis may also be present.
Thalidomide can cause congenital heart defects, malformed kidneys, urinary, reproductive and gastro-intestinal malformations. Thalidomide also resulted in mental retardation, according to the Otis, the Organization of Teratology Information Specialists (see Reference 3). According to RXList, mortality at or shortly after birth for babies born after thalidomide exposure is 40 percent (see Resources below).