Pregnancy Risk Factor: You may find this labelling when reading about drugs and the associated risk if taken by a pregnant patient
The FDA has extablished five categories A, B, C, D, or X to indicate the potential of a systemically absorbed drug for causing birth defects. The key differentiation among the categories rests upon the reliability of documentiation and the risk:benefit ratio.
Controlled studies in pregnant women fail to demonstrate a risk to the foetus in the first trimester with no evidence of risk in later trimesters. The possibility of foetal harm appears remote.
Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women, or animal-reproduction studies have shown an adverse effect (other than the decrease in fertility) that was not confirmed in controlled studies on women in the first trimester and there is no ecidence of a risk in later trimesters.
Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal effects or other) and there are no controlled studies in women, or studies in women and animal are not available. Drugs should only be given if the potential benefits justify the potential risk to the foetus.
There is positive evidence of human foetal risk, but the benefits from the use in pregnant women may be acceptable despite the risk (e.g. if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective).
Studies in animals or human beings have demonstrated foetal abnormailities or there is evidence of foetal risk based on human experience, or both, and the risk of the use of the drug in pregnant women clearly outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant. i.e. NO GO.
Edit These E2 Titles
: please change to Categories for drug use during pregnancy