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Pregnancy and Lactation

I have been receiving requests for information regarding the safety of various drugs in pregnancy and lactation.  First of all, medications are grouped into 1 of 5 categories  based on the potential for producing birth defects. The categories are A, B, C, D and X.  Generally speaking, drugs that fall into either class A or B are considered safe and are routinely used.  There may be exceptions.

Category A: Controlled studies in pregnant women fail to demonstrate a risk to the fetus in the first trimester with no evidence of risk in later trimesters. The possibility of harm appears remote.

Category B: Presumed safety based on animal studies, with no controlled studies in pregnant women, or animal studies have shown an adverse effect that was not confirmed in controlled studies in women in the first trimester and there is no evidence of a risk in later trimesters.

Category C:  Studies in women and animals are not available or  studies in animals have revealed adverse effects on the fetus and there are no controlled studies in women. Drugs should be given only if the potential benefits justify the potential risk to the fetus.

Category D: There is positive evidence of human fetal risk (unsafe), however in some cases such as a life-threatening illness the potential risk may be justified if there are no other alternatives.

Category X: Highly unsafe: risk of use outweighs any potential benefit. Drugs in this category are contraindicated in women who are or may become pregnant.

Drug List

This is an abbreviated list of medications that are usually considered safe during pregnancy. Always consult your health care provider before taking any medication.
bisacodyl (Dulcolax) Cephalosporins: Ancef, Duricef, Keflex, Ceclor, Ceftin, others..)
clotrimazole (Mycelex) docusate (Colace) erythromycin (base and EES) not estolate guaifenesin (Robitussin)
insulin levothyroxine (Synthroid) methyldopa (Aldomet) nystatin
Penicillins (dicloxacillin, amoxicillin, ampicillin) pyridoxine simethicone terbutaline


National Institutes of Health, U.S. National Library of Medicine, DailyMed Database.
Provides access to the latest drug monographs submitted to the Food and Drug Administration (FDA). Please review the latest applicable package insert for additional information and possible updates.  A local search option of this data can be found here.

Pregnancy and Lactation