Indigestion is commonly called "heartburn."  However, the condition has nothing have to do with the heart. Indigestion is a burning feeling that starts in the stomach and seems to rise into the throat. It occurs when digested food from your stomach, which contains acid, is pushed up toward your esophagus. Changes in your hormone levels during pregnancy slow digestion and relax the muscle that normally prevents the digested food and acid in your stomach from entering your esophagus. Also, your enlarged uterus is pressing on your stomach and this contributes to the symptoms. 

Tips to prevent or relieve indigestion: 

• eat 5 or 6 small meals a day instead of 2 or 3 large ones
• a glass of fluid may be equal in volume to a small meal, so avoid drinking large amounts of fluids with your meals
• avoid foods that cause gas, such as spicy or greasy foods
• avoid smoking, caffeine, chocolate, and alcohol
• do not eat or drink several hours before exercising
• antacids may be helpful -- ask your health care provider for a suggestion