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

When you have inflammatory bowel disease (IBD)-whether it’s Crohn’s disease or ulcerative colitis-and you’re thinking about getting pregnant, the biggest question isn’t just can I get pregnant? It’s can I stay safe? And more importantly, can my baby?

The truth is, most women with IBD have healthy pregnancies. But only if their disease is under control. Stopping your meds out of fear can be riskier than keeping them. Studies show that active IBD at conception increases the chance of preterm birth by more than double, raises the risk of low birth weight, and even raises the chance of stillbirth. The real danger isn’t your medication-it’s your inflammation.

What Medications Are Safe During Pregnancy?

Not all IBD drugs are created equal when it comes to pregnancy. Some are proven safe. Others are not worth the risk. Here’s what the latest global guidelines say, based on data from over 1,500 pregnancies tracked in the PIANO registry and reviewed by 42 experts worldwide.

Aminosalicylates (5-ASAs) like mesalamine and sulfasalazine are considered first-line and safe to continue. You don’t need to stop them. In fact, stopping them increases your chance of a flare by up to 70%. But there’s a catch: some mesalamine brands use a coating called dibutyl phthalate (DBP)-like Asacol HD. That coating has been linked to genital abnormalities in male babies in animal studies and should be avoided. Switch to a DBP-free version like Lialda or Delzicol. Your doctor can help you switch safely.

Sulfasalazine is also safe, but it interferes with folate absorption. That’s why you need to take a higher dose of folic acid-5 mg daily-starting at least three months before conception. Folic acid reduces the risk of neural tube defects, and with sulfasalazine, you’re not just being cautious-you’re preventing harm.

Biologics: The Gold Standard for Pregnancy Safety

If you’re on a biologic-like infliximab or adalimumab-you’re in good shape. These anti-TNF drugs have been studied in over 2,000 pregnancies. The data is clear: no increase in birth defects, no higher rate of miscarriage, and no spike in preterm births compared to the general population. The PIANO registry found that 2.6% of babies exposed to anti-TNFs had a major malformation-almost identical to the 2.8% rate in unexposed pregnancies.

Doctors often adjust the timing of your last dose in the third trimester. Why? Because these drugs cross the placenta more in the later stages. By delaying your final dose until week 30 or 32, you reduce how much of the drug your baby gets right before birth. That lowers the chance of your newborn having a suppressed immune system in the first few months.

Vedolizumab, a newer biologic that targets the gut specifically, also looks safe. The CONCEIVE study followed 103 pregnancies and found no increase in serious infections or birth defects. Early data showed fewer live births, but that turned out to be because many of those women had active disease. When disease activity was controlled, the live birth rate matched the general population.

Ustekinumab, used for moderate to severe IBD, now has data from over 680 pregnancies. No red flags. No spike in birth defects. No increase in preterm delivery. The European study from 2024 showed outcomes were the same whether moms got induction therapy or just maintenance. It’s now classified as Category B-limited but reassuring data.

What to Avoid at All Costs

Some drugs are absolute no-gos during pregnancy. Methotrexate is one. It’s a known teratogen. Studies show it causes major birth defects in 17% to 27% of exposed pregnancies-think cleft palate, brain malformations, limb defects. If you’re on methotrexate, you need to stop it at least three months before trying to conceive. And you need to use reliable birth control while taking it.

Thalidomide? Forget it. Even a single dose can cause severe limb deformities. It’s banned in pregnancy for good reason.

JAK inhibitors like tofacitinib and upadacitinib are trickier. There’s not enough data yet. A small study of 11 pregnancies with tofacitinib showed no obvious harm-but 11 is too few to say it’s safe. The 2023 Crohn’s & Colitis Foundation guidelines recommend stopping these drugs at least one week before conception. For upadacitinib, experts suggest stopping 4 to 6 weeks before trying to conceive, just to be safe. The concern isn’t proven harm-it’s theoretical risk to early development.

What About Steroids?

Corticosteroids like prednisone are sometimes used to get IBD under control fast. But they’re not ideal in pregnancy, especially in the first trimester. Studies show a 1.4 to 2.3 times higher risk of cleft lip or palate if taken early on. That’s why doctors aim for steroid-free remission before conception. If you’re still on steroids when you get pregnant, don’t panic. Work with your team to taper off as quickly and safely as possible. The goal is to switch to a safer maintenance drug before your baby arrives.

Immunomodulators: Azathioprine and 6-MP

Azathioprine and 6-mercaptopurine (6-MP) have been used for decades in pregnant women with IBD. The data is solid: no increased risk of birth defects, no higher miscarriage rate. The European Crohn’s and Colitis Organisation (ECCO) gives them a Category A rating-safe with extensive data. You can keep taking them throughout pregnancy. Just make sure your blood counts are monitored monthly. These drugs can lower white blood cells, and pregnancy can make that worse.

Planning Ahead: The 3-Month Rule

The best time to talk about pregnancy isn’t when you miss your period. It’s when you start thinking about it. Experts agree: get your IBD in remission for at least three months before conceiving. And ideally, you want to be on a steroid-free regimen. Why? Because if your disease is active when you get pregnant, you’re already at higher risk-even if you take all the right meds.

That means working with your gastroenterologist and OB-GYN as a team. Don’t wait until you’re pregnant to ask, “Is this safe?” Start the conversation six months out. Get your endoscopy done if you haven’t had one in the past year. Make sure your bloodwork is clean. Adjust your meds if needed. This isn’t about being perfect-it’s about being prepared.

What Happens After Baby Arrives?

Many moms worry: “Can I breastfeed?” The answer is usually yes. Most IBD medications pass into breast milk in tiny, harmless amounts. Anti-TNFs, vedolizumab, azathioprine-all considered safe. Mesalamine? Safe. Sulfasalazine? Possibly, but your baby’s stool might turn orange. That’s harmless. The Crohn’s & Colitis Foundation says monitoring is fine, but toxicity is extremely unlikely.

And what about vaccines? Your baby can get all the standard shots-even live ones like MMR and varicella. Exposure to your medication doesn’t make them immunocompromised. The ECCO 2024 guidelines confirm this clearly: no need to delay vaccines.

Why So Much Confusion?

Here’s the problem: for decades, pregnant women were left out of drug trials. That meant doctors had to guess. Many women were told to stop everything. Many flared. Many lost pregnancies. That’s changing. The PIANO registry changed everything. It proved that continuing treatment is safer than stopping it.

But knowledge gaps still exist. A 2021 survey found only 42% of community gastroenterologists could correctly identify all pregnancy-safe IBD drugs. And 68% of pregnant women with IBD said they were anxious about their meds. That anxiety is real. But it’s based on outdated fears. The science is now on your side.

The Bottom Line

You don’t have to choose between your health and your baby’s. With the right plan, you can have both. The safest thing you can do is keep your IBD in remission. That means staying on the right meds-switching out unsafe ones, keeping the safe ones, and working with your care team long before you get pregnant.

IBD doesn’t make you a high-risk pregnancy. Uncontrolled IBD does. And with today’s guidelines, tools, and data, you have more control than ever before.