UC and Pregnancy: Eating Well to Gain the Right Amount of Weight

Medically Reviewed by Brunilda Nazario, MD on July 09, 2021
5 min read

Getting the right balance of nutrients is always important when you have ulcerative colitis. But when you're pregnant and have UC, getting a well-balanced diet is absolutely essential to ensure that your baby has enough nutrition to grow and thrive.

Gastrointestinal woes can be an everyday occurrence in people with ulcerative colitis. This painful form of inflammatory bowel disease (IBD), which causes inflammation and sores on the intestinal lining, can really take a toll on diet.

When people are in pain, they don't want to eat, so their nutrition suffers, explains Susan L. Mikolaitis, RD, LDN, clinical research dietitian in the department of gastroenterology and nutrition at Rush University in Chicago.

Here are some ways to boost your nutrition during pregnancy, and even before you get pregnant.

When in doubt about what to eat, follow the government's guidelines on nutrition during pregnancy. This balanced diet includes items such as:

  • Fortified breads and cereals
  • Vegetables (such as carrots, sweet potatoes, spinach, cooked greens, squash, tomatoes, and sweet red peppers)
  • Fruits (such as cantaloupe, honeydew melon, mangoes, prunes, bananas, apricots, oranges, grapefruit, and avocado)
  • Dairy (low-fat or fat-free milk and yogurt), if not lactose intolerant
  • Meat and beans (cooked beans and peas, nuts and seeds, lean meat and chicken)
  • Fish

Of course, that may be easier said than done. Morning sickness alone could make you swear off many of the foods on the list. And for many women with ulcerative colitis, some of the healthiest foods also may be symptom triggers.

Adjust your diet according to how you feel, but be careful not to avoid the nutritious foods you really need. Instead, get creative to get them in:

Grains. Some people with ulcerative colitis have trouble eating cereals, rice, and breads. Yet these whole grains are important because they are fortified with folic acid, a nutrient that helps prevent spina bifida and other neural tube birth defects.

If whole grains seem to trigger your ulcerative colitis symptoms, you might try quinoa and amaranth. They may be less likely to trigger your UC symptoms.

Fruits and vegetables. If they bother you, try fruit or vegetable juice instead. Just make sure it's 100% juice, with no added sugar.

"Sugar is not a good thing for patients with IBD," says Mikolaitis. Bacteria seem to be partial to disaccharides, a kind of sugar that includes table sugar. "And we think bacteria play a big role in the flare-ups of the disease," she says.

Drink pasteurized juice so you don't get E. coli or another food-borne illness, which may be dangerous for your baby.

Fish. Your doctor may have recommended that you eat more fish because it is high in omega-3 fatty acids. Omega-3s are thought to reduce inflammation, which can be beneficial for an inflammatory disease like ulcerative colitis.

But you need to make sure you don't eat fish that are high in mercury during pregnancy. Stick to low-mercury fish such as salmon, canned light tuna, pollock, catfish, and shrimp. Avoid high-mercury varieties such as king mackerel, tilefish, shark, swordfish, and albacore ("white") tuna.

Finally, make sure you are drinking enough water. Having active ulcerative colitis during pregnancy could mean more diarrhea. This can lead to dehydration if you don’t replace the fluid you lose.

Whether you are trying to conceive or are already pregnant, your diet is going to need a little boost from a vitamin supplement.

"All women considering conception should be started on a prenatal vitamin, and our patients are no different," says Uma Mahadevan, MD, director of clinical research at the Center for Colitis and Crohn's Disease and associate professor of medicine at the University of California, San Francisco.

A daily prenatal vitamin can also help replace nutrients you lose through diarrhea.

Ask your doctor whether you need additional supplements if you're not getting enough of certain nutrients. Vitamin D, calcium, potassium, and magnesium deficiencies are all common in people with IBD.

You may also need extra folic acid, because UC and some medications you may take for it make it harder for your body to absorb folic acid.

People with ulcerative colitis are more prone to developing anemia, a lack of red blood cells that can be caused by an iron deficiency. So getting extra iron is essential. But sometimes the iron in prenatal vitamins can bother women with IBD.

"For patients who have active ulcerative colitis – patients who are flaring – taking iron can be very stressful on the digestive system," Mahadevan says. Keep trying different vitamin formulations until you find one you can tolerate.

Some women with ulcerative colitis struggle to stay at the recommended weight for their height. Being underweight may increase the risk of giving birth to an underweight baby.

What's healthy? If you were at a normal weight when you got pregnant, you should aim to gain 25 to 35 pounds during your pregnancy. Increase that to 28 to 40 pounds if you started out your pregnancy underweight.

Instead of trying to eat three big meals a day, eat five smaller meals to make it easier on your digestive system. If you have to avoid certain foods because they seem to cause ulcerative colitis symptoms, ask a dietitian to help you make the healthiest choices from the foods you are able to eat.

It will be much easier for you to attain a healthy weight if you start your pregnancy off right. "If women who have ulcerative colitis are considering getting pregnant, it's always best to try to get their disease into remission before they seriously try," Mikolaitis says.

When your symptoms are under control, it's easier for you to eat well. And the better you eat, the better it will be for your ulcerative colitis and your chances of having a healthy pregnancy.