Drug Fetal Risk Categories

From Embryology

Introduction

Different countries have their own authorities that classify the relative risk of drugs to the fetus. The Australian drug classification is carried out by the Australian Government Therapeutic Goods Authority (TGA) in the United States it is the FDA. Within the authority the Australian Drug Evaluation Committee (ADEC) applies the following classification to drugs as well as indicating some therapeutic goods that have not been generally included in this categorisation. There is also an electronic 1999 PDF document Prescribing Medicines in Pregnancy (4th Edition) that is still available, but currently under revision. (More? Abnormal Development - Drugs)

Australia

Pregnancy Category A

Have been taken by a large number of 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.

Pregnancy 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. Studies in animals have not shown evidence of an increased occurrence of fetal damage.

Pregnancy Category B2

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.

Pregnancy Category B3

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.

Pregnancy Category C

Have caused or may be suspected of causing, harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible.

Pregnancy Category D

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.

Pregnancy Category X

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.


USA FDA Fetal Risk Categories

In the United States the government Food and Drug Administration (FDA) has established the following drug classification.

Category A

Controlled studies in women fail to demonstrate a risk to the fetus in the first trimester, there is no evidence of a risk in later trimesters, and the possibility of fetal harm appears remote.

Category B

Either animal reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women, or animal reproduction studies have shown on adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of risk in later trimesters).

Category C

Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women, or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.

Category D

There is positive evidence of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (eg, 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).

Category X

Studies in animals or human beings have demonstrated fetal abnormalities or there is evidence of fetal risk based on human experience or both, and the risk of use of the drug in pregnant women clearly outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant.

Germany

Gr 1

Extensive human testing and animal studies have not shown that the drug is embryotoxic / teratogenic.

Gr 2

Extensive human testing of the drug have not shown that the drug is embryotoxic / teratogenic.

Gr 3

Extensive human testing of the drug has not shown that the drug is embryotoxic / teratogenic. However, the drug appears to be embryotoxic / teratogenic in animals.

Gr 4

There has been no adequate and well-controlled studies of the drug's effects on humans available. Animal studies have shown no embryotoxic/teratogenic effects.

Gr 5

There has been no adequate and well-controlled studies of the drug's effects on humans available.

Gr 6

There has been no adequate and well-controlled studies of the drug's effects on humans on pregnant women. Animal studies have shown embryotoxic/teratogenic effects.

Gr 7

There is a risk that the drug is embryotoxic/teratogenic to the human fetus, at least in the first trimester.

Gr 8

There is a risk that the drug is toxic to fetuses throughout the second and third trimester.

Gr 9

There is a risk that the drug causes prenatal complications or abnormalities.

Gr 10

There is a risk that the drug causes hormone specific action on the human fetus.

Gr 11

There is a known risk that the drug is a mutagen/carcinogen.

Canadian HPFB Fetal Risk Categories

In Canada the Health Products and Food Branch (HPFB) provides information on health-related risks and benefits of health products and food.

MedEffect Canada: Adverse Reaction Database | Adverse Reaction Reporting

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