Pregnancy and IBD

The big picture

Most people with Crohn’s disease or ulcerative colitis can have a healthy pregnancy and a healthy baby.

The most important thing is to have your IBD calm (in remission) when you get pregnant, and to keep it calm. Active IBD is a bigger risk to a pregnancy than most IBD medicines are. When IBD is calm, pregnancy outcomes look much like those of people without IBD.

Dr. Squirell and her colleagues followed 287 women with IBD through 291 pregnancies at a specialist clinic in British Columbia. Here is what they found:

• IBD that was active before pregnancy was the strongest sign that it would be active during pregnancy.
• Babies whose mothers needed steroids for a flare were more likely to come early.
• Biologic medicines did not change how the pregnancies turned out.

Active IBD is a bigger risk to a pregnancy than most IBD medicines are.

Before you try to get pregnant

Book a planning visit with your IBD team. Do this a few months before you start trying, if you can. At this visit, your team will:

• Check that your IBD is truly calm, with tests like a stool test, blood work, an ultrasound or a scope.
• Review each of your medicines.
• Talk about vitamins, smoking, alcohol, and anything else that affects pregnancy.

Experts advise waiting until your IBD has been calm, without steroids, for at least 3 months.

Take folic acid, a B vitamin, every day. It helps prevent birth defects of the baby’s spine and brain. Start before you try to get pregnant. The dose depends on your medicines and on how well your bowel takes in food:

“Most people” means you do not take sulfasalazine and your bowel takes in food well. Sulfasalazine makes it harder for your body to use folic acid. Malabsorption means your bowel cannot take in food well. This can happen with Crohn’s in a long part of the small bowel, or after a lot of small bowel surgery. If a close family member was born with spina bifida, your team may also advise a higher dose. Many prenatal vitamins have some folic acid in them, so ask your pharmacist how to reach your dose.

Fertility

Most people with calm IBD can get pregnant. Active IBD can make it harder. Surgery to make a J-pouch (the pouch made from the small bowel after the colon is removed) can also make it harder. If you have trouble getting pregnant, fertility treatments such as IVF seem to work about as well for people with IBD.

Your medicines

Most IBD medicines are safe in pregnancy. Do not stop them on your own. Stopping can cause a flare, and a flare is riskier for your baby than the medicine.

A few pills can harm a developing baby. They must stop 3 months before you try to get pregnant. Some of them leave your body sooner than that. But 3 months also gives time to switch you to a safe medicine and make sure the new one keeps your IBD calm.

Ozanimod and etrasimod are called S1P pills.

If you get pregnant while on one of the “stop” medicines, do not panic and do not just stop it. Call your IBD team the same day.

Checkups during pregnancy

Even when you feel well, your team will check on your IBD about once each trimester (every 3 months). This usually means:

• A stool test called calprotectin. It measures inflammation in the bowel. Pregnancy does not change the result, so it is a good test to use now.
• Blood work. Some results change a little in any pregnancy, and your team knows what to expect.
• An intestinal ultrasound if needed. It uses no radiation and is safe. It works best in the first two trimesters. Later, the growing uterus can block the view.

A flexible scope can be done in pregnancy if it will change your care. CT scans and MRI with contrast dye are avoided.

Ulcerative colitis is more likely than Crohn’s to flare during pregnancy. In Dr. Squirell’s study, flares in colitis were most common in the middle of pregnancy. So keep your checkups, and call early if symptoms change.

Other things to ask about

• Low-dose aspirin. It lowers the risk of pre-eclampsia, a serious high blood pressure problem. Ask your obstetrician about starting it at 12 to 16 weeks.
• Blood clots. IBD raises the risk of blood clots in pregnancy and after birth. If you are in hospital, you may get a blood thinner shot.
• Vaccines. Non-live vaccines are safe in pregnancy and on IBD medicines. Canada advises these in every pregnancy:
  • The flu shot and a COVID-19 vaccine, at any stage.
  • Tdap, to protect your baby from whooping cough. The best time is 27 to 32 weeks.
  • RSV protection for your baby. RSV is a virus that can cause serious chest infections in babies. You can get an RSV vaccine (Abrysvo) at 28 to 36 weeks. Or your baby can get an RSV antibody shot after birth. Usually one or the other is enough. In Ontario, both are free in RSV season. Ask your team which is best for you.

Giving birth

Most people with IBD can have a vaginal birth. IBD alone is not a reason for a C-section. A vaginal birth does not cause Crohn’s disease around the bottom.

A planned C-section is usually advised if you have:

• Active Crohn’s disease around the bottom, such as an abscess or fistula. A fistula is a tunnel from the bowel to the skin or another organ.
• A fistula into the vagina, now or in the past.
• A J-pouch. A C-section helps protect the muscles that keep the pouch from leaking. Talk this choice through with your team.

Otherwise, how you give birth depends on the usual reasons your obstetrician uses for anyone.

After your baby is born

Keep taking your IBD medicine. Flares are more common in the months after birth, and they are more common in people who stop their medicine. Plan to keep up your stool tests and blood work in the first year.

Breastfeeding is encouraged. It does not cause flares. Most IBD medicines pass into breast milk in tiny amounts or not at all. You can breastfeed on 5-ASA, azathioprine, steroids, and biologics. Do not breastfeed on JAK pills or S1P pills.

Your baby’s vaccines

If you took a biologic in pregnancy, tell your baby’s doctor or nurse at the first visit.

• Most vaccines should be given on time. These are the “non-live” vaccines, which cannot cause infection. Babies exposed to biologics respond to them normally.
• Rotavirus vaccine (drops by mouth, first dose at 2 months). This is a live vaccine. The 2025 expert consensus says it may be given to babies who were exposed to biologics, and we follow that advice. A Canadian study of 191 exposed babies found it was safe. Canada’s national vaccine guide is more cautious. It says there is not enough data yet, and that waiting may be considered. But that advice was written in 2016, before these newer studies. Tell your baby’s doctor about your medicine early. The first dose must be given before your baby is 15 weeks old.
• BCG vaccine (a tuberculosis vaccine used in some communities). Your baby should not get it in the first 6 months.
• MMR and chickenpox vaccines at 1 year can be given on the usual schedule.
• RSV antibody shot (nirsevimab, Beyfortus). This is not a vaccine, and it is not live. It gives your baby ready-made antibodies against RSV. In Ontario, it is free for babies in their first RSV season (fall and winter).
• Taking a biologic only while breastfeeding does not change your baby’s vaccines.

In Dr. Squirell’s study, babies exposed to biologics had more infections, mostly minor, in their first 6 months. Few needed hospital care. Larger studies of anti-TNF medicine alone have not found more serious infections. Taking anti-TNF medicine together with azathioprine may raise the risk a little. Call your baby’s doctor about any fever or illness, as you would for any baby.

Will my child get IBD?

Most children of a parent with IBD do not get it. The chance is higher if both parents have IBD.