Hello dear, I understand your concern. In my opinion the heart burn is a routine problem faced during pregnancy due to the influence of progesterone hormone in pregnancy. As you had the gastritis before pregnancy it might get aggravated in pregnancy. But you need not worry as it can be controlled by medicines. The antacids can be taken as first line of treatment. If there is no relief then proton pump inhibitors (PPI) can be tried. Among PPI the omeprazole can be taken during pregnancy. It has good safety profile and is not associated with any harmful effects on the fetus. Nexium is almost similar to omeprazole. So you will get relief from PPI. So nothing to worry.Relax. Also dietary modifications like avoid spicy and oily diet and take food in small quantities every 2 hourly. Take buttermilk or curd daily in diet to decrease gastritis. So check for dietary modifications,antacids and PPI if needed. Don t worry.It will subside.Avoid stress. Hope this helps. Best regards...Dr.Srilatha