What causes heartburn during pregnancy?
Heartburn occurs when the valve between the stomach and the food pipe (esophagus) are unable to prevent the stomach acids from passing back into the esophagus. Pregnancy has the tendency to increase the frequency of heartburn because the hormone progesterone causes the valve to relax. This allows the stomach acid to pass into the esophagus and irritate the lining. Heartburn and indigestion are more common during the third trimester because the developing baby tends to put pressure on the intestines and the stomach. The pressure on the stomach may push contents back up into the esophagus.
