Heart burn in pregnancy, technically known as oesophagitis or gastritis is one of the commonest complaints of pregnancy. It is usually due to the relaxation of the valve between the oesophagus and stomach caused by the hormone progesterone. This relaxed valve allow acid contents from the stomach to get to an unfamiliar environment in the oesophagus leading to a burning sensation felt behind the rib cage.
The same surge of hormone explains the feeling of indigestion felt most times during pregnancy.
The way to alleviate symptoms of this nature is to sit upright during meals as this will reduce the compression on the stomach. Eat small quantities of food at frequent intervals and avoid fatty, highly spiced or pickled foods which worsen symptoms. Try and avoid going to bed immediately after eating and while sleeping maintain your head slightly elevated with more than one pillow. A cup of natural yoghurt before meals and bed time or a glass of milk could be beneficial. There are also antacids that can be made available to you by prescription from your doctors.