Identifying Human Teratogens: An Update

Abstract

A human teratogen is an agent that alters the growth or structure of the developing embryo or fetus, thereby causing birth defects. The first human teratogen identified in 1941 by an ophthalmologist, Norman Gregg, was maternal rubella infection in pregnancy, which produced a triad of defects (cataracts, heart malformations, and deafness) in the infants.[1] Following the identification of thalidomide, an antinauseant, as a major human teratogen causing severe birth defects in 1961,[2] research in teratology began to expand and there was increased awareness of the possible teratogenic impact of maternal exposures during pregnancy.