Final answer:
A drug that causes birth defects is described as teratogenic. Teratogens can cause a range of developmental issues during pregnancy, with factors such as the drug's mutagenic potency, the fetus's susceptibility, and the dosage of the drug affecting the degree of teratogenicity.
Step-by-step explanation:
A drug that is known to cause birth defects is known as teratogenic. Teratogens are substances or conditions including drugs, chemicals, radiation, or certain diseases that can cause developmental problems in a developing embryo or fetus. The degree of teratogenicity depends on several factors:
- The potency of the drug as a mutagen.
- The susceptibility of the fetus to teratogenesis.
- The dose of the teratogen.
Some known examples of teratogens include alcohol, which can cause fetal alcohol spectrum disorders with symptoms like small head size and abnormal facial features, and thalidomide, which has caused limb defects in newborns. The impact of teratogens varies widely and can include anything from minor to major birth defects, affecting the physical and cognitive development of the child.