Why Did FDA Abolish the Pregnancy Drug Categories?

Note: The Pregistry website includes expert reports on more than 2000 medications, 300 diseases, and 150 common exposures during pregnancy and lactation. These expert reports are free of charge and can be saved and shared.

Note: always follow your doctor’s instructions. Never change your medication regimen on your own.


The U.S. Food and Drug Administration (the FDA) is the agency that promotes and protects public health and is responsible for publishing safety and effectiveness information for drugs used in this country. Starting in the 1970s, the FDA used letters (A, B, C, D, and X) to classify the safety of drugs during pregnancy and lactation. In 2015, the FDA changed the way they communicate this information to consumers and patients and removed categories entirely.

What changed?

After 4 decades of the letter-based risk categories, the FDA realized that people did not understand the system and were, therefore, misinformed about the safety of drugs during pregnancy and lactation. Clinicians and patients alike were confused by the meaning of the pregnancy risk categories because the system was overly simplistic, led to misinformation, and did not adequately address the available information.

As far back as 1992, the FDA began receiving requests to change the way the safety categories were reported. They then began obtaining input from many affected groups and, in 2008, proposed the new method of reporting information in the Pregnancy and Lactation Labeling Rule.

The new method of reporting is likely more important now than ever before, since more and more women are taking chronic medications for diseases and health conditions before they get pregnant. And, women are waiting longer and longer to have children, meaning their chance of being on a medication during pregnancy is higher and higher.

Now, instead of simply reporting a letter, drug manufacturers must offer narrative sections and subsections within the prescribing information that summarizes information about not just pregnancy but also lactation and reproductive potential. The new sections look like this:

Pregnancy (includes labor and delivery): 

  • Pregnancy exposure registry
  • Risk summary
  • Clinical considerations
  • Data

Lactation (includes nursing mothers)

  • Risk summary
  • Clinical considerations
  • Data

Females and Males of Reproductive Potential

The Pregnancy section provides information about dosing and potential risks to the developing fetus and offers information about registries that collect and maintain data on how pregnant women are affected when they use the drug.

The Lactation section includes information for drugs that should not be used during breastfeeding, data regarding active metabolites that appear in breast milk, and clinical effects on the infant. Other information may include a risk and benefit and timing of breastfeeding related to drug use to minimize infant exposure.

The Females and Males of Reproductive Potential section provides information about pregnancy testing or birth control before, during, or after drug therapy, as well as a medication’s effect on fertility or pregnancy loss.

Is it better than before?

Overall, the changes to the FDA reporting system have been received positively, and most clinicians believe that the summaries provided will allow women to make more information decisions about medication use before, during, and after pregnancy.

Some of the challenges still faced with the use of medications during pregnancy relate to the lack of human data. Clinical studies are rarely performed in pregnant women, so what we know and don’t know about medications is limited and often comes from anecdotal experiences and patient reports. As an industry, drug manufacturers are evaluating and considering safe, ethical, and meaningful ways to learn about medication use during pregnancy and lactation in order to provide the most valuable information to all people who may be affected.

While the new presentation of safety information offers more clarity than the 5-letter system, there are still uncertainties related to the use of many drugs during pregnancy. Rarely is the question to use a drug satisfied with a simple “yes” or “no” answer: you and your healthcare provider will need to discuss the risks and benefits of every drug you need to take during pregnancy and your healthcare provider will need to rely on clinical judgment and experience to determine what is best for you and your baby.

Jennifer Gibson
Dr. Jennifer Gibson earned a Bachelor of Science degree in Biochemistry from Clemson University and a Doctor of Pharmacy degree from the Medical College of Virginia School of Pharmacy at Virginia Commonwealth University. She trained as a hospital pharmacist and is the author of clinical textbooks, peer-reviewed journal articles, and continuing education programs for the medical community, as well as a contributor to award-winning healthcare blogs and websites. In her free time, she enjoys running, reading, traveling, and spending time with her family.

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