Which category of medication classification indicates no harm to a human fetus?

Category A medications are classified as those that have been tested and found to pose no risk to the developing fetus during pregnancy. These medications are well-studied in pregnant women, and the evidence demonstrates that they do not have adverse effects on fetal development. This classification reflects a level of safety based on substantial human studies.

In contrast, Category B medications may be considered safe, as animal studies have not shown risks to the fetus, but there may not be enough human studies to fully confirm their safety. Category C includes medications where risks cannot be ruled out, as studies in animals have shown adverse effects, but there are no adequate studies in humans. Lastly, Category X medications are those known to cause harm and should not be used during pregnancy.

Understanding these classifications is crucial for ensuring the safety of both the mother and the fetus when considering medication during pregnancy.