Heartburn is due to acid reflux
from the stomach to the food pipe. It occurs more in pregnancy
especially in later months as the sphincter between food pipe and stomach becomes loose and due to enlarging tummy there us increased pressure which causes acid regurgitation. Eat very small and frequent meals and take light food. No tea, acidic, fried, junk and spicy food. Eat homemade food. If still problem persists take antacids.