GP Rob says: Gaviscon tablets are perfectly safe as the liquid and tablets contain ingredients that are not absorbed into the bloodstream, and so are safe to take during pregnancy.
Heartburn occurs in pregnancy because pregnancy hormones relax the valve at the top of the stomach, which allows acid and food to escape into the gullet (food pipe).
Combined with a growing baby putting pressure on your stomach, this results in the uncomfortable sensation you are experiencing.
Eat little and often, avoid bending over at the waist after eating, and wear loose clothing to lessen pressure on your stomach.
Prop the head of your bed up a little by putting books under the legs at the head end, as this helps prevent acid and food escaping from the stomach and causing heartburn when you lie down.