David said:
There are 3 common reasons for post-partum GERD
Hormonal changes: Progesterone levels increase during pregnancy, relaxing the lower esophageal sphincter (LES), which prevents stomach acid from backing up into the esophagus. After delivery, hormone levels drop, but the LES may remain relaxed for some time.
Pressure from the growing baby: During pregnancy, the growing baby puts pressure on the stomach, which can also contribute to reflux.
Increased stomach acid production: Pregnancy and breastfeeding can increase stomach acid production, which makes reflux more likely.