Two drugs for ulcerative colitis are known to cause birth defects: methotrexate and thalidomide. Ask your doctor to switch you to other drugs at least 3 months before you plan to start trying to get pregnant.
Your doctor may recommend that you stop taking steroids or take a very low dose. They can be risky during pregnancy, including a slightly higher chance that a baby will be born with a cleft palate.
Other medications for ulcerative colitis may be OK to take.