Pregnancy Categories

Category	Definitions*	Clinical Application
Category A	"Controlled studies in women fail to demonstrate a risk to the fetus in the first trimester (and there is no evidence of a risk in later trimester), and the possibility of fetal harm appears remote."	For all practical purposes, there are no Category A drugs.
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 an 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 a risk in later trimesters)."	Category B drugs include prenatal vitamins, acetaminophen and several other medications used routinely and safely during pregnancy. If there is a clinical need for a Category B drug, it is considered safe to use it.
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 C drugs have not been shown to be harmful to fetuses (if they had been, they wouldn't be Category C drugs). However, there are some reasons to be more concerned about these drugs than Category B drugs. If the pregnant patient will benefit from a Category C drug, it is generally used, although most obstetricians would prefer a Category B drug if it will give equivalently good results.
Category D	"There is positive evidence of human fetal risk, but the benefits from 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.)"	Category D drugs have some significant risks. They should be used during pregnancy only when the alternatives are worse.
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 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."	Category X drugs should not be used during pregnancy.

*Food and Drug Administration. Federal Register 1980;44:37434-67

Home · Military Medicine · Sick Call · Basic Exams · Medical Procedures · Lab and X-ray · The Pharmacy · The Library · Equipment · Patient Transport · Medical Force Protection · Operational Safety · Operational Settings · Special Operations · Humanitarian Missions · Instructions/Orders · Other Agencies · Video Gallery · Forms · Web Links · Acknowledgements · Help · Feedback

Approved for public release; Distribution is unlimited.

The information contained here is an abbreviated summary. For more detailed and complete information, consult the manufacturer's product information sheets or standard textbooks.

Source: Operational Medicine 2001, Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300.

Bureau of Medicine and Surgery
Department of the Navy
2300 E Street NW
Washington, D.C
20372-5300

Operational Medicine
Health Care in Military Settings
CAPT Michael John Hughey, MC, USNR
NAVMED P-5139
January 1, 2001

United States Special Operations Command
7701 Tampa Point Blvd.
MacDill AFB, Florida
33621-5323

*This web version is provided by The Brookside Associates, LLC. It contains original contents from the official US Navy NAVMED P-5139, but has been reformatted for web access and includes advertising and links that were not present in the original version. The medical information presented was reviewed and felt to be accurate in 2001. Medical knowledge and practice methods may have changed since that time. Some links may no longer be active. This web version has not been approved by the Department of the Navy or the Department of Defense. The presence of any advertising on these pages does not constitute an endorsement of that product or service by either the US Department of Defense or the Brookside Associates. The Brookside Associates is a private organization, not affiliated with the United States Department of Defense.

Advertise on this site