Heartburn Medications in Pregnancy: Safe Options for Antacids, H2 Blockers, and PPIs

Heartburn during pregnancy isn’t just uncomfortable-it’s common. Up to 80% of pregnant people experience it, especially in the second and third trimesters. The growing baby presses up on the stomach, and pregnancy hormones relax the valve that keeps acid down. It’s not a sign of something wrong; it’s just part of the physical shift your body is going through. But when the burning feels constant or wakes you up at night, you start wondering: What can I safely take?

First-Line Defense: Antacids Like Tums

If you’ve ever asked a pregnant friend what works for heartburn, they’ll probably say, “Tums.” And they’re right. Calcium carbonate antacids, including Tums, Rolaids, and other generic brands, are the go-to first choice. Why? Because they work fast-neutralizing stomach acid within minutes-and they’re backed by decades of safe use in pregnancy.

Calcium carbonate doesn’t just soothe heartburn. It also gives you extra calcium, which your baby needs to build bones and teeth. That’s a rare win-win. Most experts, including the Cleveland Clinic and Austin Gastroenterology, agree: if you’re going to take something, start here.

But not all antacids are created equal. Avoid those with aluminum hydroxide or magnesium trisilicate. Aluminum can build up and cause constipation or even neurological issues in rare cases. Magnesium trisilicate has been linked to fetal toxicity in animal studies, so it’s best skipped. Mylanta is okay if it’s the version with aluminum hydroxide and magnesium hydroxide-but only if you don’t have kidney problems. Always check the label.

How much is too much? Stick to no more than 1,500 mg of calcium carbonate per day unless your doctor says otherwise. That’s about four regular Tums tablets. Taking more than that over time can lead to high calcium levels in your blood, which may affect your kidneys or cause nausea. And don’t use them daily for weeks on end without checking in with your provider.

Second-Line: H2 Blockers Like Pepcid

If antacids aren’t doing the job after a few days, the next step is often an H2 blocker. These reduce acid production instead of just neutralizing it. Famotidine (Pepcid) is the top pick. It’s been studied in thousands of pregnant women and shows no increased risk of birth defects, preterm birth, or low birth weight.

Unlike antacids, which last 1-2 hours, famotidine works for up to 12 hours. That means you can take it once at night and sleep through the burning. It’s especially helpful if heartburn keeps you awake or happens right after meals.

What about ranitidine (Zantac)? Don’t use it. The FDA pulled it from the market in 2020 because of a cancer-causing contaminant called NDMA. Even if you have old bottles lying around, toss them. Pepcid is the only H2 blocker currently recommended for pregnancy.

Side effects are rare but possible: headaches, dizziness, or stomach upset in about 3-5% of users. If you feel strange after taking it, stop and call your provider. Also, don’t mix it with other medications without checking. Some antacids can interfere with how well H2 blockers are absorbed.

Third-Line: PPIs Like Prilosec

When heartburn is severe, constant, or doesn’t respond to antacids or H2 blockers, doctors may turn to proton pump inhibitors (PPIs). Omeprazole (Prilosec), lansoprazole (Prevacid), and pantoprazole (Protonix) are the most common. Omeprazole is the most studied in pregnancy-and the one most often prescribed.

PPIs work by shutting down the stomach’s acid pumps entirely. They’re powerful. Effects start in 1-4 hours and last a full day. That’s why they’re used for chronic GERD, not occasional heartburn.

But here’s the catch: while large studies haven’t shown clear birth defects linked to omeprazole, there are some concerns. A 2019 study in JAMA Pediatrics found a small increased chance of childhood asthma in kids whose mothers took PPIs during the first trimester. It didn’t prove cause and effect, but it’s enough to make doctors cautious.

That’s why PPIs are reserved for when other options fail. If you’re in your first 14 weeks of pregnancy, your provider will likely push back on starting a PPI unless your symptoms are extreme. After the first trimester, the risk drops significantly. Still, long-term use may slightly reduce calcium absorption, which matters if you’re already struggling to get enough through diet or supplements.

Only take PPIs under medical supervision. Never self-prescribe them during pregnancy. Your doctor will start you on the lowest effective dose and monitor you closely.

What to Avoid Completely

Some medications are off-limits. Pepto-Bismol? No. It contains bismuth subsalicylate, which breaks down into aspirin-like compounds. Aspirin during pregnancy increases the risk of bleeding, premature closure of a fetal blood vessel, and low birth weight. Even one dose isn’t worth it.

Also skip aluminum-containing antacids if you have kidney disease. Magnesium-based ones can cause diarrhea if overused. And never take multiple heartburn meds together unless your provider tells you to. Mixing H2 blockers and PPIs can lead to over-suppression of acid, which may cause nutrient deficiencies or gut infections.

Non-Medication Strategies That Actually Work

Medications help-but they’re not the whole story. Many women find relief just by changing how they eat and move. Here’s what works:

• Eat five or six small meals instead of three big ones. A full stomach puts more pressure on the valve.
• Avoid trigger foods: spicy dishes, fried food, chocolate, citrus, caffeine, and carbonated drinks.
• Don’t lie down for at least three hours after eating. Gravity helps keep acid down.
• Elevate your head while sleeping. Use a wedge pillow or stack a couple of regular pillows under your mattress-never just behind your head.
• Wear loose clothing. Tight waistbands squeeze your stomach.
• Chew gum after meals. It increases saliva, which helps neutralize acid.

These aren’t just “old wives’ tales.” They’re backed by clinical guidelines from the Cleveland Clinic and the American College of Obstetricians and Gynecologists. In fact, many women find that combining lifestyle changes with occasional antacids gives them the best results.

When to Call Your Doctor

Heartburn is normal. But if you’re having any of these, it’s time to get checked:

• Difficulty swallowing or pain when swallowing
• Vomiting blood or black, tarry stools
• Unexplained weight loss
• Heartburn that wakes you up every night
• Symptoms that don’t improve after two weeks of safe OTC meds

These could signal something more serious-like GERD complications, a hiatal hernia, or even a rare condition called HELLP syndrome. Don’t wait. Your provider can do a simple exam or recommend further testing if needed.

What About Breastfeeding?

If you’re nursing, most of these medications are still safe. Calcium carbonate passes into breast milk in tiny amounts and won’t affect your baby. Famotidine is considered low-risk, and omeprazole is one of the preferred PPIs for nursing mothers. The amount that gets into milk is far below what would harm a baby.

Still, talk to your provider. If you’re taking higher doses or long-term meds, they may want to monitor your baby’s weight or check for signs of fussiness or diarrhea. But in most cases, you can safely use these meds while breastfeeding.

Final Thoughts

Heartburn during pregnancy is frustrating, but you’re not alone-and you don’t have to suffer. Start with simple, safe steps: eat smaller meals, avoid triggers, and sleep propped up. If you need help, Tums are your best friend. If that’s not enough, famotidine is a reliable next step. Save PPIs for when nothing else works-and only with your doctor’s okay.

The goal isn’t to eliminate heartburn completely. It’s to manage it safely so you can sleep, eat, and enjoy your pregnancy without constant discomfort. Always check with your provider before starting any new medication-even if it’s over the counter. Your body is doing something incredible. Let the right tools help you through it.