How to Read Pregnancy and Lactation Labeling on Drugs: A Clear Guide for 2025

If you’ve ever looked at a prescription label and seen a letter like C or D next to "Pregnancy," you’re used to the old system. But since 2015, that’s changed-dramatically. The FDA no longer uses those simple letters to tell you if a drug is safe during pregnancy or breastfeeding. Instead, you now get real, detailed information. The problem? Most people don’t know how to read it. And if you’re pregnant, breastfeeding, or helping someone who is, that gap can be dangerous.

Why the Old System Failed

For over 35 years, drugs were labeled with pregnancy categories: A, B, C, D, and X. It looked simple. Category A? Safe. Category X? Don’t take it. But that simplicity was misleading. A Category C drug didn’t mean "maybe dangerous." It meant: "We tested it on animals, and something weird happened-but we don’t have good human data." That’s not the same as saying "this causes birth defects." Yet, many doctors and patients treated it like a grade: C = bad, B = okay, A = perfect.

The truth? Less than 2% of prescription drugs were Category A. Over 70% were Category C. That didn’t mean 70% of drugs were risky. It meant we just didn’t have enough data. The old system didn’t help you weigh risks. It just scared you.

The New System: PLLR Explained

In 2015, the FDA replaced the letter system with the Pregnancy and Lactation Labeling Rule (PLLR). This isn’t just a tweak. It’s a complete rewrite. Now, every prescription drug’s label has three clear sections under "Use in Specific Populations":

• 8.1 Pregnancy
• 8.2 Lactation
• 8.3 Females and Males of Reproductive Potential

Each section follows the same structure: Risk Summary, Clinical Considerations, and Data. No more guessing. No more letters. Just facts.

How to Read the Pregnancy Section (8.1)

Start with the Risk Summary. This is where the old system fell apart-and the new one shines. Instead of saying "Category C," it tells you:

• The background risk of birth defects in any pregnancy is 3% to 5%.
• For this drug, the risk is 1.5 times higher than that.
• That means a 4.5% risk instead of 3%-not a huge jump, but meaningful.

It also tells you when the risk happens. Was it only in the first trimester? Did it affect heart development? Did it increase the chance of miscarriage? The summary gives you the numbers, not just a warning.

Next, Clinical Considerations. This is your action plan. It might say:

• "Monitor fetal growth every 4 weeks after 20 weeks of gestation."
• "Avoid use in the third trimester due to risk of neonatal withdrawal."
• "Consider alternative therapy if pregnancy is planned."

These aren’t vague suggestions. They’re specific, timed, and based on real patient data.

Finally, the Data section. This is for the curious-or the skeptical. It lists the studies: how many women were included, what kind of study it was (observational, registry, randomized trial), and whether results were adjusted for other factors like smoking or age. It tells you if the data is strong or shaky.

How to Read the Lactation Section (8.2)

Breastfeeding safety is often an afterthought. Not anymore. The lactation section gives you exact numbers:

• "Infant exposure is less than 5% of the maternal weight-adjusted dose."
• "Peak milk concentration occurs 2 hours after maternal dose."
• "No adverse effects reported in 80 breastfed infants over 6 months."

This isn’t "probably okay." It’s "here’s exactly how much gets into the milk, when, and what we’ve seen in real babies." Some drugs are known to pass into breast milk in high amounts-like certain antidepressants or seizure meds. The label will say if there’s a risk of drowsiness, poor feeding, or liver issues. It even tells you if the drug has a long half-life, meaning it builds up over time.

If a drug has a pregnancy exposure registry, it’s listed here too. These registries track outcomes in real time. Over 25,000 pregnancies were recorded in 2022 alone-up from just 5,000 before 2015. That’s progress.

What About Fertility and Contraception? (8.3)

This section matters if you’re planning a pregnancy-or trying not to get pregnant. It tells you:

• "Pregnancy testing required before starting treatment."
• "Two forms of contraception recommended (failure rate <1%)."
• "Discontinue drug 30 days before attempting conception."

For men, it might say: "Drug may reduce sperm count. Consider sperm banking before treatment." This used to be ignored. Now it’s required.

What’s Missing? The Real Challenges

The PLLR is better-but it’s not perfect. Labels are longer. A typical drug now has 300 to 500 extra words. That’s a lot to read during a 10-minute appointment.

Many doctors still rely on apps like MotherToBaby or TERIS because the label doesn’t give them a quick answer. Pharmacists report spending 5 to 7 extra minutes per prescription explaining the new labels to patients. And in emergencies? No one has time to parse paragraphs.

Also, not all data is equal. Many studies are small. Some don’t include women of color-only 15% of registry participants are Black or Hispanic, even though they make up 30% of U.S. pregnancies. That’s a gap.

How to Use This Info in Real Life

If you’re pregnant or breastfeeding and your doctor prescribes a new drug:

1. Ask for the FDA-approved prescribing information (the full label). Most can pull it up on their phone.
2. Go straight to Section 8.1 and 8.2. Skip the rest.
3. Look for the Risk Summary. Is the increase in risk absolute or just relative? A "2-fold increase" from 1% to 2% is very different from 10% to 20%.
4. Check Clinical Considerations. Are there monitoring rules? Timing limits?
5. Don’t ignore the lactation section-even if you’re not breastfeeding now, things change.
6. If you’re unsure, call MotherToBaby at 1-800-962-5847. They’re free, confidential, and staffed by specialists.

What’s Next? The FDA’s 2025 Plan

By 2025, the FDA plans to have 100% of pregnancy and lactation labels updated. They’re also testing visual icons-like traffic light colors (green/yellow/red)-to make risk levels easier to spot at a glance.

They’re also pushing for better data from underrepresented groups. If you’re pregnant and take a medication, consider joining a pregnancy registry. Your data helps future moms.

Bottom Line

The new labeling system doesn’t give you a quick answer. But it gives you a better one. It replaces fear with facts. It replaces guesswork with data. It treats you like a partner in care-not just a patient.

You don’t need to be a doctor to understand it. You just need to know where to look. And now, you do.