What do FDA Pregnancy Ratings Mean?
Is It Safe? Medication Being Pregnant

What do FDA Pregnancy Ratings Mean?

By Amy Morrison
FDA pregnancy ratings explained

The Food and Drug Administration (the American agency whose job it is to oversee the production and safety of drugs and medications) has a special FDA pregnancy rating system for pregnant people. This rating system has five categories that indicate the potential a drug may have to cause fetal birth defects if taken while pregnant.

These categories do not apply to breastmilk and nursing people, just FYI.

The FDA categories are:

Category A

Adequate 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). Example: Folic Acid

Category B

Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women. Examples: Acetaminophen (Tylenol), Amoxicillin

Category C

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. Examples: Coedine, Zoloft,

Category D

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. Example: Valium, Xanax

Category X

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. Examples: Accutane, Lipitor

Category N

FDA has not classified the drug.

If you read through these descriptions you can see that the FDA is carefully weighing the pros and cons of the potential for fetal birth defects against the potential harm to the mother if she doesn’t get her needed medication.

As far as I can tell there are two clear categories here. Category A translates to: ‘Go take your pills! You and baby both get to be happy!’ And Category X seems to indicate ‘The risk of birth defects with his drug is so high, it is totally not worth it. Just don’t take it.’ I can only assume they chose ‘X’ (instead of ‘E’) for this category to illustrate a significant separation from the other categories, and because ‘Fuck No’ would be too long.

The tricky part seems to be all the categories in the middle. Some of these drugs caused birth defects in animals but can’t ethically be tested on pregnant women – “could you swallow this pillow case of Zoloft in your third trimester and tell us what happens?”. Some of these drugs are risky in the first trimester and seem to have less risk of being harmful later in the pregnancy. Some of these drugs didn’t cause much harm if taken infrequently but risk increased with added exposure.

FDA pregnancy rating cheat sheet

If you want to track down any medication you’re currently or thinking about taking you can try:

I’ll warn you though, these pages are designed like a basement bingo hall and category listings aren’t always easy to find. In all fairness, they are most likely trying to make your doctor or pharmacist your go-to so a medication isn’t getting a thumbs up without the whole picture – what may be safe for you may not be safe for someone else. You get the gist.

To sum up FDA pregnancy ratings

Bottom line is: talk to your doctor about the safety of any drugs you have to take while pregnant – you never know what will make rats glow this month.



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