Pregnancy and inflammatory bowel diseases: Current perspectives, risks and patient management

Table 1 Food and Drug Administration pregnancy category definitions[66]

Category	Definition
A	AWC studies in humans have failed to demonstrate a risk to the fetus in the all trimesters of pregnancy
B	Studies in animals have failed to demonstrate a risk to the fetus and there are no AWC studies in humans and the drug usage benefits outweigh its potential risks, or, there were no studies performed either in animals nor in humans
C	There are no AWC studies in humans but studies in animals have shown a side effect on the fetus, and the drug usage benefits outweigh its potential risks, or, there were no studies performed either in animals nor in humans
D	Investigational or marketing experience or studies in humans reported positive evidence of human fetus risk, but it can still be used in spite of its potential risks if there are extreme measures as in a life-threatening situation or serious disease in which safer drugs are ineffective or contraindicated
X	Studies in animals or humans have demonstrated fetal abnormalities, or, there investigational or marketing experience, or both reported positive evidence of fetal risk, and, the potential risks of drug usage clearly outweigh any possible benefit (for example, other forms of therapy are available)

AWC: Adequate and well-controlled.