Pregnancy category

Pregnancy category

The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does "not" include any risks conferred by pharmaceutical agents or their metabolites that are present in breast milk.

Every drug has specific information listed in its product literature. In the UK, while no preset categories are applied, the British National Formulary gives a table of drugs to be avoided or used with caution in pregnancy, and does so using a limited number of key phrases. [cite book |title=British National Formulary |chapter=Appendix 4: Pregnancy |edition=55 |date=March 2008]

United States

In 1979, the United States Food and Drug Administration (FDA) introduced a classification of fetal risks due to pharmaceuticals. This was based on a similar system that was introduced in Sweden just one year earlier.

The United States FDA has the following definitions for the pregnancy categories:

United States FDA Pharmaceutical Pregnancy Categories
Pregnancy Category AAdequate and well-controlled 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).
Pregnancy Category BAnimal 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 which have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.
Pregnancy Category CAnimal 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.
Pregnancy Category DThere 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.
Pregnancy Category XStudies 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.

One characteristic of the FDA definitions of the pregnancy categories is that the FDA requires a relatively large amount of high-quality data on a pharmaceutical for it to be defined as Pregnancy Category A. As a result of this, many drugs that would be considered Pregnancy Category A in other countries are allocated to Category C by the FDA.

Australia

Australia has a slightly different pregnancy category system from the United States - notably the subdivision of Category B. The system, as outlined below, was established by the Congenital Abnormalities Sub-committee of the Australian Drug Evaluation Committee (ADEC).

ADEC Pregnancy Categories (Australia)
Pregnancy Category ADrugs which 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 B1Drugs 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 B2Drugs 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.
Pregnancy Category B3Drugs 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.
Pregnancy Category CDrugs 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.
Pregnancy Category DDrugs 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.
Pregnancy Category XDrugs that 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.

The subcategorisation of Category B, while offering additional information which may be of benefit in evaluating the risk vs benefit, presents its own problem of data reliability - since human data is lacking or inadequate, the subcategorisation is based on animal data. Furthermore, allocation of a drug in Category B does not necessarily imply greater safety than Category C.

Drugs in Category D are not absolutely contraindicated in pregnancy, unlike Category X. In some cases Category D was assigned to a drug on the basis of suspicion.

Categorisation of selected agents

The data presented is for comparative and illustrative purposes only, and may have been superseded by updated data.

Classification of some agents, based on different national bodies
Pharmaceutical agentAustraliaUnited States
Acetaminophen/ParacetamolAB
AmoxicillinAB
Amoxicillin with clavulanic acidB1B
IsotretinoinXX
PhenytoinDD
RifampicinCC
ThalidomideXX
TheophyllineAC
TetracyclineDD

Notes

References

* http://www.prn2.usm.my/mainsite/bulletin/sun/1995/sun24.html
* - links provided for 1999 4th edition and subsequent updates
*
* Food and Drug Administration. Federal Register 1980;44:37434-67
*


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Category — may refer to: *Category (philosophy) *taxonomic category Taxonomic rank *Category (grammar) *Category (mathematics) * Categories (Aristotle) *Category (Kant) *Categories (Stoic) *Categories (game), a game involving naming categories of things… …   Wikipedia

  • Pregnancy Risk Category — Die Schwangerschaftskategorie beschreibt Arzneistoffe hinsichtlich ihres Risikos, bei Anwendung während der Schwangerschaft Schäden und Missbildungen am Fötus zu verursachen. Inhaltsverzeichnis 1 Einleitung 2 Deutschland: Risikogruppen zur… …   Deutsch Wikipedia

  • Pregnancy Discrimination Act — A federal law that prohibits discrimination against employees based on the basis of pregnancy, childbirth, or related medical conditions. Category: Employment Law & HR Nolo’s Plain English Law Dictionary. Gerald N. Hill, Kathleen Thompson Hill.… …   Law dictionary

  • Pregnancy — For pregnancy in non human animals, see Pregnancy (mammals). Pregnancy Classification and external resources A pregnant woman at the end of the second trimester. ICD 10 …   Wikipedia

  • Immunization during pregnancy — Immunization during pregnancy, that is the administration of a vaccine to a pregnant woman, is not a routine event as it is generally preferred to administer vaccines either prior to conception or in the postpartum period. When widespread… …   Wikipedia

  • Drugs in pregnancy — Drugs used during pregnancy can have temporary or permanent effects on the fetus. Any drug that acts during embryonic or fetal development to produce a permanent alteration of form or function is known as a teratogen. Contents 1 Prescribing for… …   Wikipedia

  • Domestic violence and pregnancy — Part of a series on Violence against women …   Wikipedia

  • Beginning of pregnancy controversy — Controversy over the beginning of pregnancy usually occurs in the context of the abortion debate.[not verified in body] Depending on where pregnancy is considered to begin, some methods of birth control or infertility treatment might be… …   Wikipedia

  • Denial of pregnancy — (also called pregnancy denial) is a rare form of denial exhibited by women to either the fact or the implications of their own pregnancy. One study found that women who denied their pregnancy represented only 0.26% of all deliveries. [1] Contents …   Wikipedia

  • Major Diagnostic Category — The Major Diagnostic Categories (MDC) are formed by dividing all possible principal diagnoses (from ICD 9 CM) into 25 mutually exclusive diagnosis areas. MDC codes, like DRG codes, are primarily a claims and administrative data element unique to… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”