Ulcerative Colitis and Pregnancy: What You Need to Know

Many women with ulcerative colitis go on to have healthy pregnancies and babies — and with the right preparation, the odds are very much in your favor. The key is planning ahead, staying in remission before conception, and working closely with both your gastroenterologist and OB-GYN throughout pregnancy. This guide covers everything UC patients need to know about pregnancy, from medication safety and fertility to managing flares and planning for delivery.

Does UC Affect Fertility?

One of the first questions many women with UC ask is whether their diagnosis will make it harder to get pregnant. The reassuring answer, in most cases, is no. UC itself does not significantly reduce fertility. Women with well-controlled UC have fertility rates comparable to the general population, and most are able to conceive without difficulty.

The exception is active disease. When UC is poorly controlled and inflammation is ongoing, the body is under significant physiological stress, which can temporarily disrupt the hormonal signals that regulate ovulation and the menstrual cycle. Getting your disease under control before trying to conceive is one of the most important steps you can take.

There is one surgical factor that deserves specific attention. Women who have had J-pouch surgery (ileal pouch-anal anastomosis) may experience reduced fertility due to scarring around the fallopian tubes from the pelvic surgery. Studies suggest that J-pouch surgery can reduce natural conception rates significantly. If you are considering J-pouch surgery and pregnancy is part of your future plans, discuss the timing carefully with your gastroenterologist and surgeon before proceeding. Some women choose to complete their family before pursuing surgery.

For men with UC, sulfasalazine can temporarily reduce sperm count and motility — a well-documented side effect. Switching to mesalamine (which does not carry this effect) before trying to conceive typically resolves the issue within a few months. If your male partner has UC and is on sulfasalazine, this is worth raising with their gastroenterologist.

• UC itself does not significantly reduce fertility in most women
• Active inflammation can temporarily affect ovulation and fertility
• J-pouch surgery can reduce fertility in women due to pelvic scarring — discuss timing before surgery if pregnancy is planned
• Men on sulfasalazine: switching to mesalamine resolves sperm count reduction

Planning Pregnancy With UC — What to Do Before You Conceive

Preparation makes a significant difference in pregnancy outcomes for women with UC. The goal before conception is to give yourself the best possible starting point — which means stable disease, optimized nutrition, and a medication plan that is safe to continue through pregnancy.

Aim to be in remission for at least three to six months before trying to conceive. Women who are in remission at the time of conception are far more likely to remain in remission throughout pregnancy. Active disease at conception increases the risk of a difficult pregnancy course, preterm birth, and low birth weight. It is worth taking the time to get your UC fully under control before stopping contraception, even if that feels frustrating.

Review every medication you are taking with your GI doctor before stopping contraception. Some medications are safe during pregnancy; others need to be stopped well in advance. This conversation should happen before you begin trying — not after you discover you are pregnant. Your doctor may adjust your regimen proactively to ensure you are on the safest possible combination.

Get your nutritional levels checked. UC, particularly when it has been active, can deplete key nutrients. Before pregnancy, ask your doctor to check your iron, vitamin D, folate, and B12 levels. Deficiencies in any of these can affect fertility and early fetal development. Supplementing where needed before conception is straightforward and important.

Start folic acid supplementation if you have not already. All women trying to conceive are advised to take folic acid to reduce the risk of neural tube defects, and this applies equally to women with UC. If you are on sulfasalazine, higher-dose folic acid supplementation is recommended because sulfasalazine interferes with folate absorption.

Finally, make sure your OB-GYN is fully informed about your UC diagnosis and current medications before your first prenatal appointment. Ideally, establish care with an OB-GYN who has experience managing high-risk pregnancies or inflammatory bowel disease, and ensure your GI doctor and OB-GYN are communicating throughout your pregnancy.

• Aim for remission for at least 3–6 months before trying to conceive
• Review all medications with your GI doctor before stopping contraception
• Check iron, vitamin D, folate, and B12 levels — correct deficiencies before conception
• Start folic acid supplementation; higher dose if on sulfasalazine
• Inform your OB-GYN about your UC and current medications from the start

How Does Pregnancy Affect UC?

The relationship between pregnancy and UC runs in both directions — your UC affects your pregnancy, and your pregnancy can affect your UC. Understanding what to expect can help you stay calm and act quickly when needed.

The most important predictor of your UC course during pregnancy is your disease status at conception. Women who are in remission when they conceive have roughly a 70 to 80 percent chance of remaining in remission throughout the pregnancy. That is an encouraging number, and it is the reason remission at conception is so strongly emphasized. Your body is already doing the right things, and pregnancy itself — through its immunomodulatory effects — often helps keep the disease quiet.

Women with active disease at conception face a different picture. Active inflammation at the time of conception increases the likelihood that the disease will remain active or worsen during pregnancy. The first trimester and the postpartum period are the two times when flares are most common. Postpartum flares in particular are well-recognized, partly because the immunological changes of pregnancy reverse after delivery.

It is important to say clearly: UC that is well-controlled does not directly cause miscarriage or birth defects. The fears that many newly diagnosed women have about whether UC will prevent them from having children or harm their babies are understandable, but the evidence is reassuring. The risks that do exist — preterm birth, low birth weight, small for gestational age — are primarily associated with active, uncontrolled disease. Controlled disease carries risks much closer to the general population.

This is why treating a flare promptly during pregnancy matters so much. Untreated inflammation is not a neutral choice — it carries its own risks for both mother and baby, and in most cases those risks exceed the risks of the medications used to treat it.

Which UC Medications Are Safe During Pregnancy?

Medication safety in pregnancy is one of the most anxious conversations for UC patients, and it is important to approach it with accurate information rather than fear. Many UC medications have a well-established safety profile in pregnancy, and stopping medication without guidance is often more dangerous than continuing it.

Generally considered safe during pregnancy:

• Mesalamine (5-ASA) — one of the best-studied medications in pregnancy, considered safe throughout all three trimesters. Most gastroenterologists recommend continuing it without interruption.
• Sulfasalazine — also considered safe, but must be taken with high-dose folic acid supplementation because it interferes with folate absorption. Many patients are maintained on sulfasalazine throughout pregnancy without issues.
• Corticosteroids (prednisone, prednisolone) — used short-term for flares and considered acceptable for that purpose. Prolonged use carries some risk including gestational diabetes and preterm birth, so the goal is always the shortest effective course.
• Biologic medications (TNF inhibitors: infliximab, adalimumab, certolizumab pegol) — TNF inhibitors cross the placenta, particularly in the third trimester. Most evidence to date suggests they are low risk, but timing of the final dose before delivery is something to discuss with your care team. Certolizumab has the least placental transfer of the three. Continuing biologics is generally preferred over stopping them and risking a flare.
• Vedolizumab — a gut-selective biologic with limited but growing data in pregnancy. Current evidence is generally reassuring, and most IBD specialists consider it low risk based on available data.

Medications to avoid or use with extreme caution:

• Methotrexate — absolutely contraindicated during pregnancy. It is a known teratogen that causes serious birth defects and pregnancy loss. If you are on methotrexate, you must stop it at least three to six months before trying to conceive and use reliable contraception during that washout period. This conversation needs to happen with your GI doctor well in advance.
• Thalidomide — contraindicated in pregnancy due to severe teratogenic effects.
• JAK inhibitors (tofacitinib, upadacitinib) — there is limited safety data in human pregnancies, and animal studies have shown concerns. Most IBD specialists advise against using JAK inhibitors during pregnancy unless there is no other option, and most recommend transitioning to a biologic before conception if possible.

The most important rule in all of this: never stop or change any UC medication without first consulting your gastroenterologist. The risks of a medication are always weighed against the risks of uncontrolled disease. A decision made in fear — stopping a biologic because of something read online — can trigger a severe flare that poses far greater risks than the medication itself.

Managing a UC Flare During Pregnancy

If you think you are having a flare during pregnancy, the most important thing to do is contact your GI doctor promptly — the same day, not after a few days of waiting to see if it improves. Early treatment protects both you and your baby.

Mild flares may be managed by optimizing your existing mesalamine dosing — your gastroenterologist may recommend a higher dose or adding a rectal formulation, both of which are safe in pregnancy.

Moderate flares may require a short course of corticosteroids. While steroids during pregnancy are not ideal, the evidence shows that a short course to control a moderate flare is safer than leaving active inflammation untreated. Your doctor will use the lowest effective dose for the shortest time necessary.

Severe flares may require hospitalization, IV medications, and close monitoring by both your GI team and obstetric team working together. In the rare situation where medical therapy fails during a severe flare, surgery may be necessary — a sobering reality, but one that your medical team will handle with the safety of both you and your baby as the priority.

The underlying message is the same in all cases: untreated severe inflammation poses more risk to your pregnancy than most UC medications used to treat it. Do not delay seeking help out of fear about medication safety. Your doctors will make the safest possible choices given the situation.

Delivery and UC — What to Expect

Most women with UC are able to deliver vaginally and do not require a cesarean section because of their UC alone. Vaginal delivery is the default for women without specific obstetric indications.

There are situations where a C-section may be recommended. Women who have had J-pouch surgery are often advised toward cesarean delivery to protect the sphincter complex and avoid damaging the pouch repair. Women with active perianal disease — fistulas, abscesses — may also be better served by a cesarean. Your OB-GYN and GI doctor will discuss your specific situation in the third trimester and make a plan together.

Begin that delivery planning conversation early — ideally by 28 to 32 weeks. Knowing your plan in advance reduces stress and ensures everyone on your care team is aligned. Also make a postpartum plan before delivery — postpartum flares are common as the immunological shifts of pregnancy reverse and the physical and emotional demands of a newborn add to your body’s stress load. Discuss with your GI doctor whether any medication adjustments should be made in anticipation of the postpartum period.

Breastfeeding With UC Medications

Breastfeeding is beneficial for both mother and baby, and most UC medications are compatible with it. The general principle is the same as in pregnancy: do not make changes without guidance, and discuss each medication individually with your gastroenterologist and pediatrician.

Mesalamine is considered compatible with breastfeeding. Infant exposure through breast milk is low, and no adverse effects have been well documented.

Biologic medications — most are considered compatible with breastfeeding, with very limited transfer into breast milk. Infliximab and adalimumab in particular have large molecular weights that limit their passage into milk, and what does pass is largely broken down in the infant’s digestive system. Current IBD guidelines generally support continuing biologics while breastfeeding.

Corticosteroids used short-term for a flare are generally compatible with breastfeeding. If you are on a higher dose, some doctors recommend waiting two to four hours after taking the dose before nursing to reduce infant exposure, though this is a precaution rather than a firm requirement.

Whatever medications you are on, check each one individually with your GI doctor and your baby’s pediatrician before you begin breastfeeding. Do not stop a medication without guidance.

Questions to Ask Your GI Doctor Before and During Pregnancy

Going into appointments with specific questions helps you make the most of limited time and ensures nothing important falls through the cracks. Here are the key questions to raise with your gastroenterologist when pregnancy is on your horizon.

• Is my UC stable enough to try to conceive? Get a clear answer on where your disease stands and what remission looks like in your case.
• Which of my current medications are safe to continue during pregnancy? Review the full list — not just the UC medications, but everything you take.
• Do I need to make any changes before stopping contraception? Some medications require a washout period before conception is safe.
• How will we monitor my UC during pregnancy? Ask about the frequency of check-ins, which tests are safe during pregnancy, and what the threshold is for escalating care.
• What should I do if I think I am having a flare? Have a clear action plan — who to call, what to take, and when to go to the hospital.

For a full list of questions to bring to your GI appointment — including pregnancy-specific questions and questions about treatment planning — see our free GI doctor questions checklist.

Medical Disclaimer

This article is for educational purposes only and does not constitute medical advice. UC and pregnancy involve many individual factors, and the guidance here is intended to help you understand your situation and ask better questions — not to replace the advice of your care team. Always consult your gastroenterologist and OB-GYN before making any decisions about pregnancy, medications, or UC management during pregnancy.