When you have inflammatory bowel disease (IBD)-whether it’s Crohn’s disease or ulcerative colitis-and you’re planning a pregnancy, the biggest question isn’t just can I get pregnant? It’s can I stay safe-for you and your baby. The truth is, the biggest danger isn’t your medication. It’s your disease being active.
Uncontrolled IBD Is the Real Threat
Many women worry that their IBD drugs might harm the baby. But research shows something more urgent: if your IBD is flaring when you get pregnant, you’re at much higher risk for serious problems. Women with active disease at conception are 2.3 times more likely to have a preterm baby, 1.8 times more likely to have a low-birth-weight infant, and 1.6 times more likely to experience stillbirth compared to those in remission. These aren’t small risks. They’re life-changing.
That’s why experts now say: stay in remission. The goal isn’t just to avoid symptoms. It’s to get your gut quiet-ideally with endoscopic healing-before you even try to conceive. Most guidelines recommend being in stable, steroid-free remission for at least three months before pregnancy. Stopping your meds to “be safe” often backfires. A flare during pregnancy is harder to control, and steroids, which are sometimes used in flares, carry their own risks, especially in the first trimester.
What Medications Are Safe?
Not all IBD drugs are created equal when it comes to pregnancy. Some are proven safe. Others are risky. And some? We’re still learning.
Aminosalicylates (5-ASAs) like mesalamine and sulfasalazine are the first-line go-to. They’ve been used for decades in pregnant women with no clear link to birth defects. The Crohn’s & Colitis Foundation and European Crohn’s and Colitis Organisation (ECCO) both say you can keep taking them. But here’s the catch: not all mesalamine brands are the same. Asacol® and Asacol HD® use a coating called dibutyl phthalate (DBP), which animal studies and some human data link to genital malformations in male babies. If you’re on Asacol, switch to Lialda, Delzicol, or Apriso-DBP-free versions-before getting pregnant. Sulfasalazine blocks folate absorption, so take a high-dose folic acid supplement (at least 0.8 mg, often 1-5 mg daily) to protect against neural tube defects.
Anti-TNF drugs like infliximab (Remicade) and adalimumab (Humira) have the strongest safety record of any biologic. Over 2,000 pregnancies tracked in the PIANO registry show no increase in birth defects, preterm birth, or low birth weight compared to the general population. These drugs cross the placenta, especially in the third trimester, so some doctors will pause dosing around week 30 to reduce drug levels in the baby. But don’t stop early-keeping the drug going through most of pregnancy keeps your disease under control. Your baby will be fine. They’ll clear the drug naturally after birth, and live vaccines (like MMR) are still safe at the usual ages.
Vedolizumab (Entyvio) is newer, but data is reassuring. The CONCEIVE study followed 103 pregnancies. No birth defects. No increased infections. Early reports showed fewer live births, but that was because many women in that group had active disease. When researchers adjusted for disease activity, the numbers looked just like the general population. It’s now considered a solid option, especially for women who don’t respond to anti-TNFs.
Ustekinumab (Stelara) has data from over 680 pregnancies. No red flags. Rates of preterm birth, low birth weight, and birth defects matched the general U.S. population. A 2023 European study of 78 infants exposed to ustekinumab found no increased risks, even when mothers got induction doses early in pregnancy. It’s now in the “limited but reassuring” category.
What to Avoid Completely
Some drugs are absolute no-gos. Methotrexate is a known teratogen-it causes severe birth defects in 17-27% of exposed pregnancies. If you’re on it, you must stop at least three months before trying to conceive. Thalidomide is even worse-linked to limb deformities and other catastrophic issues. Never take it during pregnancy.
JAK inhibitors like tofacitinib and upadacitinib are trickier. There’s very little data. A small study of 11 pregnancies on tofacitinib showed no obvious harm, but because these drugs affect the JAK-STAT pathway-which is critical for early embryo development-experts recommend stopping them at least one week before conception (for tofacitinib) or 4-6 weeks before (for upadacitinib). If you’re on one of these, talk to your doctor about switching to a safer option before you start trying.
What About Azathioprine and 6-MP?
These immunomodulators have been used safely in pregnancy for over 30 years. Studies show no increased risk of birth defects or miscarriage. The biggest concern is low white blood cell counts in the mother, so regular blood tests are needed. But if your IBD is controlled on these drugs, there’s no reason to switch. Stopping them increases flare risk-and that’s far more dangerous than the drugs themselves.
Delivery and Breastfeeding
Most IBD medications are safe during delivery and breastfeeding. Anti-TNFs, vedolizumab, ustekinumab, and 5-ASAs all pass into breast milk in tiny amounts-far below levels that would affect the baby. The ECCO guidelines say you can breastfeed while on these drugs without concern. Sulfasalazine is debated, but even then, the amount in milk is minimal. No need to pump and dump. And yes, your baby can still get all their routine vaccines, including live ones like rotavirus and MMR. Exposure to your meds doesn’t make them immunocompromised.
How to Plan Ahead
This isn’t something to figure out the month you get a positive test. Plan at least 3-6 months before conception. That means:
- Getting your IBD into remission with your gastroenterologist
- Switching to pregnancy-safe meds if you’re on methotrexate or a JAK inhibitor
- Starting high-dose folic acid
- Setting up coordinated care between your GI doctor and OB-GYN
Many women don’t realize their GI doctor should be part of their prenatal team. In fact, only 42% of community gastroenterologists could correctly list all safe IBD drugs in a 2021 survey. Don’t assume your OB knows the details. Bring your medication list. Ask: “Is this safe? Should I switch?”
The Bigger Picture
The science is moving fast. The PIANO registry has tracked over 1,500 pregnancies since 2007. New studies like VERSA and PLACENTA are looking at long-term child development and how much of the drug actually crosses the placenta. By 2025, a shared decision-making tool will help patients and doctors weigh risks more clearly.
What hasn’t changed: your health matters more than you think. You’re not just a patient-you’re a future parent. And the best gift you can give your baby is a healthy, stable mom. Medications aren’t the enemy. Uncontrolled inflammation is.
Can I get pregnant if I have IBD?
Yes, absolutely. Most women with IBD can have healthy pregnancies. The key is being in remission before conception. Active disease increases risks like preterm birth and low birth weight, but well-controlled IBD doesn’t reduce fertility or pregnancy success.
Is mesalamine safe during pregnancy?
Yes-but only if it’s a DBP-free formulation. Avoid Asacol® and Asacol HD® because they contain dibutyl phthalate, which has been linked to genital malformations in male fetuses. Switch to Lialda, Delzicol, or Apriso before trying to conceive. These are considered safe throughout pregnancy.
Should I stop my biologics during pregnancy?
No, don’t stop them unless your doctor advises it. Anti-TNFs like infliximab and adalimumab are safe and should be continued. Some doctors pause them around week 30 to reduce drug levels in the baby, but stopping earlier increases your risk of a flare. Vedolizumab and ustekinumab can also be continued safely throughout pregnancy.
Is it safe to breastfeed while on IBD medication?
Yes. Most IBD medications-anti-TNFs, vedolizumab, ustekinumab, 5-ASAs, and azathioprine-pass into breast milk in very small amounts that are not harmful. You do not need to pump and dump. Your baby can still receive all routine vaccines, including live ones.
What if I’m on methotrexate and want to get pregnant?
Stop methotrexate immediately and talk to your doctor. It’s a known teratogen and can cause severe birth defects. Wait at least three months after your last dose before trying to conceive. Your doctor will help you switch to a safer medication like azathioprine or a biologic.
Do I need to see a specialist before getting pregnant?
Yes. Coordinate care between your gastroenterologist and obstetrician. Many OB-GYNs aren’t trained in IBD medication safety. Bring your full medication list, your last colonoscopy results, and your remission status. Planning ahead reduces risks and improves outcomes for both you and your baby.
What to Do Next
If you’re thinking about pregnancy:
- Check your current meds-especially if you’re on mesalamine, methotrexate, or a JAK inhibitor.
- Book an appointment with your GI doctor at least 6 months before trying to conceive.
- Start high-dose folic acid now, even if you’re not actively trying.
- Ask for a referral to a high-risk OB if you’ve had complications before.
The goal isn’t perfection. It’s control. You don’t need to be symptom-free forever. But you do need to be stable-medication and all-before you get pregnant. Your baby deserves that. And so do you.