Heartburn affects up to two-thirds of pregnant women, and most of it is preventable with the right timing, positioning, and food choices. The burning sensation happens because pregnancy hormones relax the muscular valve between your esophagus and stomach, letting acid flow upward. As your uterus grows, physical pressure on the stomach makes things worse. The good news: a few targeted changes can dramatically reduce how often it happens.
Why Pregnancy Causes Heartburn
Progesterone, the hormone that rises steadily throughout pregnancy, directly relaxes the smooth muscle lining your digestive tract. It does this by boosting nitric oxide production in those muscle cells, which triggers relaxation. The valve at the bottom of your esophagus is one of those smooth muscles, and when it loosens, stomach acid can splash upward.
In the first and second trimesters, hormones are the main driver. By the third trimester, your growing uterus physically pushes up against your stomach, compressing it and making reflux even more likely. A study on meal timing found that simply being in the third trimester increased the odds of reflux by 66% compared to earlier in pregnancy, independent of other factors.
Time Your Last Meal Carefully
This is one of the most powerful changes you can make. Eating within two hours of lying down is strongly linked to reflux during pregnancy. In one study, a short gap between your last meal and bedtime increased the odds of reflux symptoms nearly thirteenfold. It was also tied to a four-and-a-half-fold increase in reflux-related insomnia. Aim to finish eating at least two to three hours before you recline for the night or even for a nap.
Smaller, more frequent meals also help. A full stomach increases pressure against that already-relaxed valve. Five or six small meals spread throughout the day keeps your stomach from overfilling at any point.
Foods and Drinks to Limit
Certain foods relax the esophageal valve further or stimulate extra acid production. The main ones to watch:
- Greasy or fried foods, which slow stomach emptying and increase pressure
- Spicy foods, which can irritate the esophageal lining directly
- Tomatoes and tomato-based sauces, which are naturally acidic
- Citrus fruits and juices, for the same reason
- Carbonated drinks, which expand the stomach with gas
- Caffeine, which relaxes the valve and increases acid secretion
You don’t necessarily need to eliminate all of these permanently. Pay attention to which ones trigger your symptoms and reduce those specifically. Many women find that tomatoes and citrus bother them most, while others react more to fatty foods. Keeping a simple food log for a week or two can help you identify your personal triggers.
Sleep on Your Left Side, Elevated
Sleeping position makes a real difference. When you lie on your left side, your esophagus sits higher than your stomach, which means gravity works in your favor to keep acid where it belongs. Right-side sleeping does the opposite, positioning the stomach above the esophageal opening and making reflux more likely.
Elevating the head of your bed adds another layer of protection. Propping the head end up by about 15 to 20 centimeters (roughly 6 to 8 inches) using bed risers or a wedge pillow lets gravity pull acid down and away from your esophagus while you sleep. Stacking regular pillows under your head alone tends to create a bend at the waist rather than a true incline, which can actually increase abdominal pressure.
Ginger for Nausea and Mild Reflux
Ginger has solid evidence behind it during pregnancy, particularly for nausea and vomiting. A meta-analysis of multiple trials found it reduced nausea significantly compared to placebo, and in some studies it outperformed vitamin B6. It’s considered safe for both mother and baby, with side effects limited to occasional mild stomach discomfort.
Ginger tea, ginger chews, or ginger biscuits are all reasonable options. The evidence is strongest for nausea rather than acid reflux specifically, but many women find it settles their stomach enough to reduce that burning feeling, especially when nausea and reflux overlap in the first trimester.
Antacids: What’s Safe and How Much
Calcium carbonate antacids are a common first-line choice during pregnancy and double as a calcium supplement. However, there’s an important upper limit. For women 19 and older, total calcium intake from all sources (food, supplements, and antacids combined) should stay below 2,500 mg per day. For those 14 to 18, the ceiling is 3,000 mg. Exceeding these amounts can lead to milk-alkali syndrome, a condition where dangerously high calcium levels develop and can affect kidney function.
Avoid antacids that contain aluminum in high doses or sodium bicarbonate (baking soda), as these can cause fluid retention or other issues during pregnancy. If you’re reaching for antacids more than a few times a day and still getting breakthrough symptoms, that’s a sign to talk to your provider about stepping up to something stronger.
When Stronger Medications Are Needed
For heartburn that doesn’t respond to diet changes and antacids, acid-reducing medications are the next step. H2 blockers like famotidine work by reducing the amount of acid your stomach produces and are considered safe during pregnancy. They’re typically recommended for mild to moderate symptoms that persist despite lifestyle changes.
For severe heartburn, proton pump inhibitors (PPIs) are an option. All PPIs except omeprazole have been classified as safe for use in pregnancy. Omeprazole carries a slightly more cautious classification, but a large Danish study examining over 840,000 births found no association between PPI use in the first trimester and birth defects. A separate meta-analysis of seven studies also found no link between PPI exposure during pregnancy and congenital malformations, miscarriage, or premature delivery, including when omeprazole was analyzed separately. One notable finding from the Danish study: PPI use in the one to four weeks before conception was associated with a small increased risk, so women planning to become pregnant may want to discuss stopping PPIs beforehand.
Habits That Help Day to Day
Beyond food choices and medication, a few simple habits can reduce reflux episodes throughout your day. Stay upright for at least 30 minutes after eating. Avoid bending at the waist to pick things up (bend at the knees instead). Wear loose-fitting clothing around your midsection, since tight waistbands increase abdominal pressure. Chewing sugar-free gum after meals can stimulate saliva production, which naturally neutralizes acid in the esophagus.
Drinking fluids between meals rather than with them helps prevent your stomach from becoming overly full. Sipping water throughout the day is fine, but downing a large glass alongside a full plate makes reflux more likely.
When Heartburn Might Be Something Else
Most pregnancy heartburn is uncomfortable but harmless. Rarely, upper abdominal pain that feels like heartburn can be a sign of preeclampsia or HELLP syndrome, particularly if it’s located under the ribs on the right side or radiates to the right shoulder. These conditions typically appear after 20 weeks and come with other warning signs: sudden swelling in the face or hands, severe headaches, vision changes, or a sharp rise in blood pressure. If your “heartburn” doesn’t respond to antacids, feels different from your usual reflux, or is accompanied by any of these symptoms, it needs prompt medical evaluation.