Pregnancy heartburn feels like a burning sensation in the center of your chest that can rise up into your throat, often accompanied by a sour or bitter taste in the back of your mouth. The pain is typically mild but persistent, and it can catch you off guard if you’ve never experienced acid reflux before. It’s one of the most common pregnancy complaints, affecting about 72% of women by the third trimester.
The Sensation and Where You Feel It
The burning starts behind your breastbone, roughly in the middle of your chest, and can travel upward along the path of your esophagus toward your throat. Some women describe it as a warm, acidic pressure rather than sharp pain. Others notice it more as a hot sensation radiating outward from the center of their chest. The intensity ranges from a mild warmth to a burning that makes it hard to get comfortable.
Along with the burn, you may notice a sour or bitter taste creeping into the back of your throat or mouth. This is stomach acid making its way up your esophagus. Some women also feel a lump-like sensation in their throat or find themselves burping more than usual. The discomfort tends to get worse when you bend over, lie down, or eat a large meal.
Why Pregnancy Makes Heartburn So Common
Two things are working against you. First, rising progesterone levels throughout pregnancy relax the ring of muscle at the top of your stomach that normally keeps acid from flowing backward into your esophagus. As progesterone climbs, that muscular valve loses pressure, making it easier for acid to escape upward. This is why heartburn tends to get progressively worse: it affects about 22% of women in the first trimester, 39% in the second, and 72% in the third.
Second, your growing uterus physically pushes your stomach upward and compresses it, which increases the pressure on that already-relaxed valve. This combination of hormonal relaxation and physical crowding is why even women who have never had heartburn before can develop it during pregnancy, particularly in the final months.
When It Typically Hits
Heartburn is most likely to flare after meals, especially large ones. Lying down within an hour or two of eating makes it worse because gravity is no longer helping keep acid in your stomach. Nighttime is a common trouble spot for this reason. Many pregnant women find that heartburn disrupts their sleep, particularly in the third trimester when the uterus is at its largest and progesterone levels are at their peak.
Certain foods are more likely to trigger episodes: spicy dishes, citrus, tomato-based foods, chocolate, and anything high in fat. Carbonated drinks and caffeine can also contribute. But triggers vary from person to person. Some women find that even bland meals cause burning if they eat too much at once.
What Helps Relieve It
Smaller, more frequent meals reduce the amount of acid your stomach produces at any one time and put less pressure on that weakened valve. Staying upright for at least two to three hours after eating gives gravity time to keep acid where it belongs. When you do lie down, elevating your upper body with a wedge pillow can make a noticeable difference. Sleeping on your left side also helps acid clear from the esophagus faster compared to lying on your back or right side.
For medication, antacids containing calcium carbonate are often considered the first choice during pregnancy. Antacids with aluminum or magnesium are also generally regarded as safe. If antacids alone aren’t enough, acid-reducing medications like famotidine (sold as Pepcid) are considered safe across all trimesters. Avoiding tight-fitting clothing around your midsection can also reduce pressure on your stomach.
When the Pain Might Be Something Else
Most pregnancy heartburn is harmless, but there’s one situation where chest or upper abdominal pain deserves immediate attention. Preeclampsia, a serious blood pressure condition of pregnancy, can cause pain under the ribs on the right side that gets confused with heartburn or indigestion. The key differences: preeclampsia pain tends to be sudden, severe, and located specifically in the upper right abdomen rather than centrally behind the breastbone. It’s often accompanied by other symptoms like severe headaches, vision changes, sudden swelling in the face or hands, or protein in the urine.
If your “heartburn” feels different from usual, is sharp rather than burning, sits under your right ribs, or comes with any of those additional symptoms, that’s worth a call to your provider right away. Straightforward heartburn, by contrast, is the familiar central chest burn that responds to antacids and positional changes.