In which category of medication classification are fetal abnormalities reported, and the drug is not to be used in pregnant women?

The classification of medication that indicates fetal abnormalities and prohibits use in pregnant women is Category X. This category means that studies in both animals and humans have demonstrated fetal abnormalities, and there is significant evidence of fetal risk based on human experience. Medications in this category are contraindicated in pregnancy due to the potential for severe adverse effects on the developing fetus. Therefore, healthcare providers must avoid prescribing Category X drugs to pregnant women, as the risks far outweigh any potential benefits.

Category A includes medications that have been shown to pose no risk to the fetus in any trimester, making it safe for use during pregnancy. Category B indicates that animal studies have not shown any risk to the fetus, but there are not enough well-controlled studies in pregnant women, so they may be used with caution. Category D medications do demonstrate risk to the fetus but may be considered in situations where the benefits can justify the potential risks. In contrast, Category X is the most serious classification in terms of fetal harm and is strictly avoided during pregnancy.