Heartburn is such a common feature of pregnancy that it might almost be regarded as normal. As the uterus enlarges, particularly after about the 20th week, it pushes the stomach up against the diaphragm, and this can predispose to gastro - oesophageal reflux, where stomach contents pass up from the stomach to the oesophagus. The lining of the oesophagus, unlike that of the stomach, is not resistant to the acidic stomach contents, and their presence causes pain. The symptoms can be eased by a number of medications which neutralise the acid and thicken the stomach contents. It’s also helped by eating little and often, by avoiding highly spiced foods and by using an extra pillow at night.