Pregnancy Category for Drugs

The pregnancy category of a medicine is used to classify it based on an assessment of the risk for fetal injury if the medicine was used by the mother during pregnancy.

Different countries use different systems to categorize drugs, however they are all based on the same principles.

USA:
Category A:
No risk in controlled human studies: Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
Category B:
No risk in other studies: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women, or animal studies have shown adverse effects, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester. eg amoxicillin
Category C:
Risk not ruled out: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Category D:
Positive evidence of risk: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. eg diclofenac
Category X:
Contraindicated in pregnancy: Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits. eg thalidomide, isotretinoin
Category N:
The FDA has not yet classified the drug into a specified pregnancy category.

Australia:
The TGA database can be searched to get the pregnancy classification of medicines in Australia.
Category A:
Drugs which have been taken by many pregnant women and women of childbearing age without an increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed. eg amoxicillin, lidocaine
Category B1:
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. eg terbinafine, loratadine
Studies in animals have not shown evidence of an increased occurrence of fetal damage.
Category B2:
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed.
Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of fetal damage.
Category B3:
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed.
Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans. eg triamcinolone
Category C:
Drugs which, owing to their pharmaceutical effects, have caused or may be suspected of causing, harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible. eg diclofenac, methoxyflurane, diazepam
Category D:
Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects.
Category X:
Drugs which have such a high risk of causing permanent damage to the fetus that they should not be used in pregnancy or when there is a possibility of pregnancy. eg thalidomide, isotretinoin

Related Topics:
Pregnancy and the Feet | Pregnancy Testing | Pregnancy/Obstetrics | Morning Sickness | Exercise and Pregnancy | Pregnancy and diabetes

Page last updated: @ 2:44 am

 
Comments are closed.