During pregnancy the hormones which relax smooth muscle in other parts of the body (for example, the uterus and lining of the blood vessels) also relax the muscle at the entrance of the stomach (called the cardiac sphincter). Because of this, acid produced in the stomach can “regurgitate” and irritate the lining of the food tube (the esophagus). In the stomach a layer of acid-proof mucus protects the stomach from being burned. The esophagus does not have this protective layer.
You may find that certain things you eat cause heartburn. Foods that contain hot spices are the more obvious culprits, but just about anything which you drink, or chew and swallow can cause stomach acid production and provide a liquefied substance which you can regurgitate. Also, the position you assume after you have eaten may make a significant difference. If you have food (solid or liquid) in your stomach and lie down, some of the stomach contents (including the acid) leak past the cardiac sphincter and move into the esophagus. The acid irritates the lining of the esophagus. It can be very uncomfortable.
So…..avoid foods which you know cause heartburn. Don’t lie down or even slouch in a chair for a couple of hours after you’ve eaten. Eat several hours before you go to bed at night. Try not to eat more than your stomach can comfortably accomodate. You may use most antacids during pregnancy, if you don’t over-use them. Both chewable and liquid forms will work to buffer stomach acid, but the liquid antacids will coat the esophagus on the way down. If you find yourself using an antacid several times every day, talk to your doctor or midwife.
There are some health problems which have symptoms which mimic simple heartburn. Fortunately, peptic ulcer disease usually improves somewhat in pregnancy. Some of the more common drugs used to treat peptic ulcer disease can be used in the second half of pregnancy, and may help considerably with severe cases of heartburn. Gallstones usually cause very severe cramping in the middle of the upper abdomen. The pain produced often comes and goes; often associated with meals. Gallstones can be diagnosed with ultrasound, but are usually not surgically removed during pregnancy unless the symptoms are severe. A severe form of toxemia/pre-eclampsia called HELLP syndrome is often associated with a persistent abdominal pain due to stretching of the liver capsule. This pain is usually in the upper abdomen, sometimes more to the right side.