Category | Interpretation |
---|---|
A | Controlled studies show no risk |
Adequate, well-controlled studies in pregnant women have failed to demonstrate risk to the foetus | |
B | No evidence of risk in humans |
Either animal findings show risk (but human findings do not) or, if no adequate studies have been done, animal findings are negative. | |
C | Risk cannot be ruled out |
Human studies are lacking and animal studies are either positive for foetal risk or lacking as well. However, potential benefits may justify the potential risk. | |
D | Positive evidence of risk |
Investigational or postmarking data show risk to foetus. Nevertheless, potential benefits may outweight the risk. | |
X | Contraindicated in pregnancy |
Studies in animals or humans, or investigational or postmarketing reports have shown foetal risk which clearly outweighs any possible benefit to the patient. |