Nearly 1 in 100 Canadians has inflammatory bowel disease. Too many believe it rules out having children

I often reflect on the advice of an outdated article on inflammatory bowel disease (IBD) and pregnancy from 1956. It stated:

“There should be no doubt that a woman with ulcerative colitis who wishes to have a child should be advised to postpone until the colitis is inactive — sometimes this may mean waiting forever.”

As a gastroenterologist specializing in IBD, I sit across from women weekly seeking updated advice on how their disease affects pregnancy. Crohn’s disease and ulcerative colitis, the two main forms of IBD, affect nearly one per cent of Canadians and are usually diagnosed in adolescence and early adulthood. An increasing number of young women are navigating life’s stages while managing a chronic condition.

Historical caution

Historically, women with IBD were cautioned against having children, or advised to choose between treating their bowel disease and having a healthy infant. While this caution was founded in real concerns about higher disease activity and complications, it was not a necessary ultimatum then and certainly isn’t now with modern treatments. However, I still meet patients who have internalized that message built on fear and outmoded concerns.

Many expectant parents wonder whether IBD could be inherited by their children, and most overestimate it. If one parent has Crohn’s, a child’s risk is roughly one in 10; for ulcerative colitis it’s lower.

Since the early 2000s, biologics (medications targeting the immune signals that drive IBD) have revolutionized disease management. They allow lasting remission, healing of damaged intestines and restore normalcy and quality of life.

With these medications came new questions, and the initial approach to pregnancy was one of reasonable caution: ceasing medication in late pregnancy when placental transfer starts to occur and fetal exposure becomes possible.

Unfortunately, this approach led to many women with well-controlled disease not only experiencing flares but also developing the very complications we had been attempting to avoid, such as pre-term birth and low birth weight.

Treating IBD in pregnancy

Caution about taking medication during pregnancy is often well-intentioned, but may also be misguided. The current evidence empowers us to treat IBD and focus on the mother’s health for a healthy infant, and much of my job comes down to reassurance.

Our reassurance comes from many observational studies, but most clearly from an American study called PIANO (Pregnancy in Inflammatory Bowel Disease and Neonatal Outcomes), which followed 1,700 pregnancies among women with IBD.

Most medications to control IBD did not raise rates of birth defects, miscarriage, premature birth or infection in babies. However, disease activity did raise these risks. Disease is considered active when there is inflammation in the bowel detected on imaging, endoscopy, stool or blood tests — regardless of whether symptoms are flaring. Later follow-up work also found no rise in childhood cancers.

In 2025, a global consensus statement on IBD and pregnancy synthesized the latest evidence and expert opinion. Its message is one of cautious reassurance. It’s recommended that most IBD medications — including biologics, azathioprine, 6-mercaptopurine and 5-aminosalicylic acid — be continued throughout pregnancy and breastfeeding.

Corticosteroids can also be used, but they are limited to treating active disease because their use is more often associated with premature and low- birth-weight babies. However, corticosteroids pose lower risk than uncontrolled disease. They should be used for the shortest time possible, with an alternate long-term medication for disease control.

A few drugs are exceptions and should be stopped: methotrexate causes serious birth defects and must be stopped three months before conception. Newer medications like Janus kinase inhibitors and sphingosine 1-phosphate receptor modulators should be avoided, as animal studies show harm to fetal development.

The message on medications is to plan ahead and not panic: speak with your gastroenterologist before conception if you can, and if you’re already pregnant, reach out early in case changes are needed.

Pregnancy and the immune system

IBD is what is called an “immune-mediated” disease. Put simply, the immune system is misfiring and causing inflammation in the bowel when there is nothing harmful to target.

This is particularly relevant because the immune system is affected by pregnancy and the postpartum period. Some immune-mediated diseases improve in pregnancy, while with IBD, nearly 40 per cent experience flares. Importantly, those with good pre-conception disease control are significantly less likely to have active disease during pregnancy.

So objective assessment of active inflammation — by colonoscopy, blood and stool tests or imaging — is strongly recommended before trying to conceive.

Most normal pregnancies are plagued by gastrointestinal symptoms, from nausea to abdominal pain to constipation. Even blood in bowel movements from hemorrhoids can be benign. This makes monitoring challenging, so close monitoring regardless of symptoms is important.

Blood work and stool tests are commonly checked each trimester. More invasive monitoring like colonoscopy should not be routine, but can be done if needed to evaluate disease activity without significant risk.

An exciting recent advance is intestinal ultrasound, which lets the gastroenterologist assess for bowel inflammation at the bedside in clinics.

In a 2025 study of 377 pregnancies, inflammation on ultrasound predicted worse outcomes even when the mother felt well and other tests were normal. A thick bowel wall in mid-pregnancy carried about four times the risk of premature birth. Absence of symptoms is not enough; the bowel wall is a leading indicator of a smouldering flare, and ultrasound, where available, is an excellent new resource.

All of this evidence points one way: the best time to prepare for a healthy pregnancy is before it starts. Women with IBD are more likely to remain childless by choice. If that is an informed decision I validate it, and IBD itself does not limit contraception options. But surveys suggest this more often traces back to fear and patchy knowledge than the disease, which good counselling can change.

It rarely occurs to patients to call their gastroenterologist to talk about pregnancy. If you have IBD and are thinking about a family, please ask. These pregnancies are a team sport: they go best when the gastroenterologist, obstetrician, family doctor and the rest of the care team give the same advice.