Final answer:
Drugs with proven teratogenic effects are classified as Pregnancy Category X, denoting high risk of birth defects with no outweighing benefits. Teratogens like heroin, cocaine, methamphetamine, alcohol, and thalidomide can cause severe fetal harm, underscoring the importance of avoiding these substances during pregnancy.
Step-by-step explanation:
The correct classification for drugs that have demonstrated teratogenic effects in women is Pregnancy Category X. This category indicates that the risks involved with using the drug during pregnancy clearly outweigh any possible benefits. Teratogens can cause serious birth defects or malformations, and these substances have varying effects depending on factors such as the potency of the teratogen, susceptibility of the fetus, and the dose or duration of exposure.
Substances like heroin, cocaine, methamphetamine, and even alcohol are known to be harmful to fetal development. Alcohol, for example, is the leading preventable cause of intellectual disabilities in children due to its teratogenicity, causing fetal alcohol spectrum disorders (FASD). Thalidomide is a well-known teratogen that caused severe limb deformities when it was used by pregnant women.
Environmental factors like exposure to certain chemicals, diseases, and radiation can also be teratogenic. Examples include chemical compounds in pesticides and plastics, viruses such as HIV and rubella, as well as deficiencies in essential nutrients like folic acid during pregnancy.