Pregnancy heartburn feels like a burning sensation that starts behind your breastbone and can rise up through your throat. It’s one of the most common pregnancy complaints, affecting about 26% of women in the first trimester and climbing to nearly 56% by the third. The burning is usually mild, but it can be persistent and uncomfortable, especially after meals or at night.
What the Sensation Actually Feels Like
The hallmark feeling is a warm or burning discomfort in the center of your chest, right behind the breastbone. It often travels upward into the neck and throat, which is what makes it feel different from other types of stomach upset. Many women describe it as a churning, acidic heat rather than a sharp pain.
Along with the burn, you may notice a sour or bitter taste in the back of your throat. This happens when stomach acid creeps far enough up to reach your mouth. Other sensations that commonly accompany it include bloating or pressure in your belly, frequent burping, nausea, and regurgitation, where swallowed food comes back up partially. These symptoms typically show up within 30 minutes to an hour after eating, though sometimes the delay is longer. Bending over, lying down, or lifting something after a meal makes it noticeably worse.
Why Pregnancy Makes Heartburn So Common
Two things work together to cause it: hormones and physical pressure. Progesterone, which rises steadily throughout pregnancy, has a direct relaxing effect on smooth muscle. The ring of muscle at the bottom of your esophagus that normally keeps stomach acid from traveling upward loosens under progesterone’s influence. As progesterone levels climb higher with each trimester, that valve gets progressively weaker, which is why heartburn tends to get worse as pregnancy advances.
The second factor is your growing uterus. By the third trimester, the uterus takes up enough space to push your stomach upward and compress it. This physical crowding forces stomach contents back toward the esophagus. The combination of a weaker valve and increased pressure on your stomach explains why more than half of pregnant women experience heartburn in their final months.
How It Changes Across Trimesters
Heartburn can start early, but it follows a clear pattern of escalation. About one in four women experience reflux symptoms in the first trimester, when progesterone is rising but the uterus is still small. By the second trimester, prevalence reaches about 33%. The third trimester is the peak, with nearly 56% of women affected as both hormonal and mechanical pressures hit their highest point. For most women, symptoms resolve after delivery once progesterone drops and the uterus is no longer compressing the stomach.
Common Triggers
Certain foods and habits are more likely to set off an episode. Spicy, fried, or fatty foods slow digestion and give acid more opportunity to creep upward. Citrus fruits, tomato-based foods, chocolate, caffeine, and carbonated drinks are frequent culprits. Large meals are worse than small ones because a full stomach puts more pressure on that already-weakened valve.
Timing matters too. Eating within two to three hours of lying down is one of the most reliable triggers for nighttime heartburn. Tight clothing around the waist can also increase abdominal pressure enough to push acid upward.
Ways to Reduce It
Smaller, more frequent meals are one of the simplest changes you can make. Eating five or six smaller portions throughout the day keeps your stomach from getting too full at any one time. Staying upright for at least two to three hours after eating gives gravity a chance to keep acid where it belongs.
For nighttime symptoms, elevating your upper body helps. A wedge pillow or raising the head end of your mattress creates a gentle incline that discourages acid from traveling up the esophagus while you sleep. Lying flat is one of the worst positions for reflux.
Over-the-counter antacids containing calcium carbonate or aluminum and magnesium compounds are generally regarded as safe during pregnancy. Calcium-based antacids are often the first choice because they provide the added benefit of extra calcium. Gas-relief products containing simethicone are also considered safe since the ingredient isn’t absorbed into the bloodstream. If antacids alone aren’t enough, certain acid-reducing medications can be used, though most providers prefer to hold off on those during the first trimester. Your provider can help you decide what makes sense for your situation.
When It Might Not Be Heartburn
Most pregnancy heartburn is harmless, but there’s one scenario worth knowing about. Pain in the upper right area of your abdomen, under the ribs, can feel a lot like heartburn or indigestion. But this type of pain, called epigastric pain, can be a sign of preeclampsia, a serious blood pressure condition in pregnancy. The Preeclampsia Foundation specifically warns that this pain is often confused with heartburn, gallbladder problems, or even the baby kicking.
The key differences: preeclampsia-related pain tends to be more persistent, located more to the right side, and often accompanied by other symptoms like sudden swelling in the face or hands, severe headaches, or vision changes. If you develop upper abdominal pain that feels different from your usual heartburn, or if it’s accompanied by any of these other signs, contact your provider right away rather than assuming it’s just reflux.