According to FDA pregnancy risk categories, which category indicates slight risks to the fetus?

Category B medications are classified by the FDA as those for which animal studies have not demonstrated any risk to the fetus, and there are no adequate and well-controlled studies in pregnant women. This suggests a relatively low risk of fetal harm, implying that the benefits of these medications may outweigh any potential risks during pregnancy. While category A indicates no risk, category B suggests a slightly elevated risk but still maintains that the available data does not show clear evidence of fetal danger, making it the safest among those indicating any level of risk.

Categories A through D reflect increasing levels of concern about potential risks to the fetus, with D indicating known risks, thus affirming that category B is correct as it denotes the lowest level of risk among these classifications.