Updated: August 2011
CATEGORY A : Controlled studies in women have failed to demonstrate a risk of the fetus.
CATEGORY B : Animal studies have shown no riks but no controlled human studies have been performed, OR animal studies have shown an adverse effect that has not been confirmed in human studies.
CATEGORY C : Animal studies have revealed adverse effects and there are no controlled studies in women or studies in women and animals are not available. Benefit must exceed risk.
CATEGORY D : There is evidence of fetal adverse effects but the benefit may outweigh the risks.
CATEGORY E : There is strong evidence of fetal abnormalities in humans; Risk out weighs the benefit.