IBD and Pregnancy: Safe Medications and What You Need to Know

When you have inflammatory bowel disease (IBD) and are planning a pregnancy, the biggest question isn’t just can you get pregnant-it’s can you stay safe while doing it. The truth is, most women with IBD can have healthy pregnancies. But the real danger isn’t the medications-it’s the disease itself when it’s active.

Uncontrolled IBD Is the Real Threat

Many women worry that taking their IBD meds during pregnancy could harm the baby. But the data tells a different story. If your Crohn’s disease or ulcerative colitis is flaring when you conceive, your risk of preterm birth jumps by 2.3 times. Low birth weight? That risk goes up by 1.8 times. Stillbirth? It’s 1.6 times more likely. These aren’t small numbers. They come from tracking over 1,500 pregnancies in the PIANO registry, the largest global study of its kind.

Stopping your meds to avoid any risk to the baby often backfires. When IBD flares during pregnancy, inflammation doesn’t just affect your gut-it can trigger early labor, restrict fetal growth, or even lead to miscarriage. Experts now agree: staying in remission is far safer than going off your treatment. As one lead researcher put it, ‘These women aren’t always seen as high-risk-but uncontrolled IBD makes them one.’

Which IBD Medications Are Safe During Pregnancy?

Not all IBD drugs are created equal when it comes to pregnancy. Here’s what the latest global guidelines say, based on real data from thousands of pregnancies.

Aminosalicylates (5-ASAs): Generally Safe, But Watch the Formulation

Medications like mesalamine and sulfasalazine are considered safe to continue during pregnancy. The Crohn’s & Colitis Foundation and ECCO both recommend keeping them on. But here’s the catch: not all mesalamine brands are the same.

Asacol® and Asacol HD® use a coating called dibutyl phthalate (DBP). Animal studies and human case reports show DBP can cause genital abnormalities in male babies when taken in high doses. If you’re on Asacol, switch to a DBP-free version like Lialda, Delzicol, or Apriso before trying to conceive. Your doctor can help you make the switch without triggering a flare.

Sulfasalazine is also safe, but it blocks folate absorption. That’s why you need a daily 1 mg folic acid supplement-starting at least three months before conception. Folate isn’t just for preventing neural tube defects; it helps reduce your own risk of IBD flares too.

Biologics: Anti-TNFs and Vedolizumab Are Well Studied

Anti-TNF drugs like infliximab (Remicade) and adalimumab (Humira) have the most safety data of any IBD biologics. The PIANO registry followed over 2,000 pregnancies and found no increase in birth defects, preterm birth, or low birth weight compared to the general population. These drugs are classified as Category A-safe with extensive evidence.

Vedolizumab (Entyvio) is newer, but data from the CONCEIVE study and over 100 pregnancies shows no major safety red flags. One early study suggested lower live birth rates, but that was only in women with active disease. When disease was controlled, birth outcomes matched those on anti-TNFs.

For both anti-TNFs and vedolizumab, most doctors recommend continuing them throughout pregnancy. Some may adjust the timing of your last dose in the third trimester to reduce drug levels in the newborn-but only if your disease is stable. Never stop these meds on your own.

Ustekinumab: Emerging Evidence Supports Use

Ustekinumab (Stelara) is a newer biologic, but data is growing fast. A 2023 European study tracked 78 infants exposed to ustekinumab during pregnancy. No increase in birth defects, preterm birth, or low birth weight was found-even in those exposed during the first trimester. Over 680 pregnancies are now recorded in global safety databases, with outcomes matching the general population. It’s now considered Category B-limited but reassuring data.

JAK Inhibitors: Avoid Before and During Pregnancy

Drugs like tofacitinib (Xeljanz) and upadacitinib (Rinvoq) are not recommended. While a small study of 11 pregnancies on tofacitinib didn’t show obvious harm, the sample size is too small to be reassuring. These drugs affect the JAK-STAT pathway, which plays a key role in early fetal development. The 2023 guidelines say: stop tofacitinib at least one week before trying to conceive. For upadacitinib, stop 4-6 weeks before. There’s just not enough safety data yet.

What’s Absolutely Forbidden?

Some IBD medications are known to cause serious birth defects. These are Category X-strictly off-limits during pregnancy.

• Methotrexate: Causes major birth defects in 17-27% of exposed pregnancies. Must be stopped at least 3-6 months before conception.
• Thalidomide: A known human teratogen. Even a single dose can cause severe limb and organ malformations.

If you’re on either of these, talk to your gastroenterologist right away about switching to a safer option. Don’t wait until you’re pregnant.

Corticosteroids: Use Only When Necessary

Prednisone and other steroids are sometimes needed to control flares. But they’re not ideal during pregnancy. Taking them in the first trimester may slightly increase the risk of cleft lip or palate-by 1.4 to 2.3 times. That’s why doctors aim to use them only for short-term flare control, not long-term maintenance. If you’re on steroids, work with your team to taper off as soon as possible and switch to safer maintenance drugs.

Immunomodulators: Azathioprine and 6-MP Are Still an Option

Azathioprine and 6-mercaptopurine (6-MP) have been used safely in pregnancy for decades. Studies show no increase in birth defects, miscarriage, or preterm birth. Your doctor will still check your blood counts regularly, but these drugs are considered low-risk. Many women stay on them throughout pregnancy without issue.

Planning Ahead: When to Talk to Your Doctor

The best time to plan your pregnancy isn’t when you miss your period-it’s before you even try. Experts recommend:

• Getting your IBD into remission for at least 3 months before conception
• Switching to pregnancy-safe medications at least 3-6 months ahead of time
• Starting folic acid (1 mg daily) at least 3 months before trying
• Having your doctor coordinate with your OB-GYN before you conceive

Many women don’t realize their gastroenterologist should be part of their prenatal team. A 2021 survey found only 42% of community gastroenterologists knew all the pregnancy-safe IBD drugs. Don’t assume your doctor has the latest info. Bring the guidelines with you.

What About Breastfeeding?

Most IBD medications are safe while breastfeeding. Anti-TNFs, vedolizumab, and 5-ASAs pass into breast milk in very small amounts-far below levels that would affect the baby. Sulfasalazine is a bit trickier because it breaks down into sulfa, which can rarely cause jaundice in newborns. But studies show the risk is extremely low, and most pediatricians say breastfeeding is fine. The Crohn’s & Colitis Foundation supports breastfeeding for women on IBD meds.

Just avoid JAK inhibitors and methotrexate while nursing. They can accumulate in breast milk and affect the baby’s immune system.

What’s New in 2025?

Research is moving fast. The VERSA study is tracking 200 pregnancies on vedolizumab with infant follow-up to age 2. The PLACENTA study is building models to predict how much of a drug crosses the placenta-so doctors can personalize dosing. And a new shared decision-making tool, expected in early 2025, will help women and their doctors weigh risks and benefits together, instead of guessing.

Pharmaceutical companies are investing millions into pregnancy safety data. That’s because women with IBD are having babies-and they deserve clear, evidence-based answers.

Final Takeaway: You Can Have a Healthy Pregnancy With IBD

The fear of medication risks is real. But the data is clear: uncontrolled IBD is far more dangerous than any of the approved treatments. You don’t have to choose between being healthy and having a baby. You can do both.

Work with your team. Switch to safe meds early. Take your folic acid. Keep your disease in remission. And remember-you’re not alone. Thousands of women with IBD have had healthy babies. With the right plan, you can be one of them.