Biologics During Pregnancy: Safety, Risks, and What You Need to Know

When you're pregnant and managing a chronic condition like rheumatoid arthritis, Crohn’s disease, or psoriasis, biologics, a class of targeted immune system drugs made from living cells. Also known as biologic therapies, they work differently than traditional pills—blocking specific proteins that cause inflammation. Many women worry: can these powerful drugs hurt the baby? The answer isn’t simple, but it’s not as scary as you might think. Research shows that certain biologics cross the placenta more than others, especially in the third trimester, but most don’t increase the risk of major birth defects when used earlier in pregnancy.

For example, adalimumab, a TNF inhibitor used for autoimmune disorders, has been studied in thousands of pregnancies and is often considered one of the safer options. So is etanercept, another TNF blocker with a long track record in pregnant patients. On the other hand, drugs like rituximab, a B-cell depleter, are usually avoided because they can affect the baby’s immune system after birth. The key isn’t avoiding all biologics—it’s choosing the right one at the right time. Many doctors recommend continuing treatment through the first and second trimesters, then stopping a few weeks before delivery to reduce newborn exposure.

It’s not just about the drug itself. Your condition matters just as much. Untreated inflammation from lupus or Crohn’s can lead to preterm birth, low birth weight, or even miscarriage. So sometimes, the bigger risk is not taking the medication. That’s why decisions around biologics during pregnancy aren’t made in a vacuum—they’re part of a bigger picture involving your health history, current symptoms, and what alternatives exist. If you’re on a biologic and planning a pregnancy, talk to your rheumatologist or gastroenterologist before stopping or starting anything. Some women switch to safer options months before conceiving. Others continue without issue. The data supports both paths, depending on the situation.

You’ll also find plenty of questions about breastfeeding. Most biologics don’t pass into breast milk in significant amounts, and even if they do, they’re proteins that get broken down in the baby’s gut—unlike small-molecule drugs that can enter the bloodstream. That’s why many moms keep using them after birth. But again, it depends on the drug. Your pharmacist or provider can help you check the specifics.

Below, you’ll find real-world advice from women who’ve navigated this, plus clear breakdowns of which biologics are linked to what outcomes. You’ll see how others managed their conditions while pregnant, what side effects to watch for, and how to talk to your care team without feeling pressured to choose between your health and your baby’s. No guesswork. No fearmongering. Just facts, experiences, and practical next steps.