Table 1. US Food and Drug Administration pregnancy category of immunosuppressive drugs for systemic inflammatory diseases.

	Description	Non-biologic immunosuppressive Drugs	Biologic immunosuppressive drugs
A	Adequate and well-controlled human studies fail to show a fetal risk	None	None
B	Animal studies fail to show a fetal risks and there are no human studies	Sulfasalazine, mesalamine A	Adalimumab, alefacept, anakinra, certolizumab, etanercept, golimumab, infliximab, ustekinumab
C	Animal studies show a fetal risk and there are no adequate human studies	Cyclosporine, gold, hydroxychloroquine b, tacrolimus	Abatacept, natalizumab, rituximab, tocilizumab
D	There is evidence of fetal risk, but the benefits may outweigh the risks	Azathioprine, cyclophosphamide, D-penicillamine, mercaptopurine, mycophenolate
X	There is evidence of fetal risk and the risks clearly outweigh any possible benefits	Leflunomide, Methotrexate

^Asacol is in category C,

^bnot officially classified