Heartburn Medications in Pregnancy: What’s Safe to Take - Antacids, H2 Blockers, and PPIs

Heartburn during pregnancy isn’t just annoying - it’s incredibly common. Up to 80% of pregnant people experience it, especially in the second and third trimesters. Your stomach is getting squeezed, hormones are relaxing the valve between your esophagus and stomach, and acid is backing up where it shouldn’t be. It’s not a sign of something wrong - it’s just how pregnancy works for many. But when the burn won’t quit, you start wondering: Can I take something for this? And if so, what’s actually safe?

First-Line Defense: Antacids Like Tums

When it comes to heartburn relief in pregnancy, calcium carbonate antacids like Tums are the go-to. Why? Because they work fast and give you something your body actually needs: calcium. Your baby’s bones are building fast, and you’re sharing your calcium supply. Tums don’t just neutralize acid - they help refill your reserves. A single tablet usually has 200-400 mg of calcium carbonate. You can take up to 500-1500 mg every 4 to 6 hours as needed, but don’t go over 10 tablets a day without checking with your provider.

Other safe antacids include Rolaids (calcium carbonate + magnesium hydroxide) and Mylanta (aluminum hydroxide, magnesium hydroxide, and simethicone). These work quickly, often within minutes, and last 1-2 hours. But watch out for ones that contain aluminum or magnesium trisilicate - those aren’t recommended. Aluminum can cause constipation, and magnesium trisilicate has unclear safety data in pregnancy.

And here’s the big one: never take Pepto-Bismol. It contains bismuth subsalicylate, which breaks down into aspirin-like compounds. Aspirin during pregnancy can affect fetal development and increase bleeding risks during delivery. Even if the bottle says “for upset stomach,” skip it.

Second-Line: H2 Blockers Like Pepcid

If antacids aren’t cutting it - maybe you’re waking up at 3 a.m. with a burning throat - your doctor might suggest an H2 blocker. These reduce how much acid your stomach makes, instead of just neutralizing what’s already there. The most commonly used and safest option is famotidine (Pepcid). It starts working in about an hour and lasts up to 12 hours. That means one dose can get you through the night.

Ranitidine (Zantac) used to be a top choice, but it was pulled from the U.S. market in April 2020 because of a cancer-causing contaminant called NDMA. Even if you still have some lying around, don’t use it. Stick with famotidine. It’s been studied in thousands of pregnant women and shows no increased risk of birth defects or complications.

Side effects are rare but can include mild headaches or dizziness in about 3-5% of users. Don’t take more than the recommended dose. If you’re using it daily for more than two weeks, talk to your provider. You might need a different approach.

Third-Line: PPIs Like Prilosec

If you’re still struggling after trying antacids and H2 blockers, your doctor may consider a proton pump inhibitor (PPI). These are the strongest acid blockers available over the counter. Omeprazole (Prilosec), lansoprazole (Prevacid), and pantoprazole (Protonix) all work by shutting down the acid pumps in your stomach lining. They take longer to kick in - 1 to 4 hours - but their effects last 24 hours or more.

Omeprazole is the most studied PPI in pregnancy. Multiple studies, including large ones published in journals like JAMA Pediatrics, haven’t found a clear link to major birth defects. But here’s the catch: one 2019 study did find a small association between first-trimester PPI use and childhood asthma. That doesn’t mean PPIs cause asthma - it just means the data isn’t perfect. Because of that, doctors only recommend PPIs when other options have failed and your heartburn is severe enough to interfere with eating or sleeping.

Long-term use of PPIs - even outside pregnancy - can affect how well your body absorbs calcium, magnesium, and vitamin B12. That’s why they’re not meant for daily, indefinite use unless absolutely necessary. If you’re on a PPI during pregnancy, your provider will likely monitor you closely and try to taper you off after delivery.

What to Avoid Completely

Not all heartburn meds are created equal. Some are outright dangerous in pregnancy:

• Pepto-Bismol - contains aspirin-like ingredients
• Ranitidine (Zantac) - withdrawn due to NDMA contamination
• Aluminum-containing antacids - like Alka-Seltzer (aspirin + aluminum)
• Magnesium trisilicate - found in some older antacid formulas
• Herbal remedies - like licorice root or chamomile - their safety in pregnancy isn’t proven

Even if something is sold as “natural,” don’t assume it’s safe. Stick to what’s been studied and approved.

Timing Matters - Especially in the First Trimester

The first 14 weeks of pregnancy are the most sensitive period for fetal development. That’s when organs are forming. Most experts - including the Northeast Georgia Physicians Group and Cleveland Clinic - recommend avoiding all non-essential medications during this time. That includes antacids, H2 blockers, and PPIs.

If you’re having heartburn early on, focus on lifestyle changes:

• Eat smaller, more frequent meals instead of three big ones
• Avoid spicy, fatty, fried, or acidic foods - citrus, coffee, chocolate, and tomatoes are common triggers
• Don’t lie down for at least 3 hours after eating
• Wear loose clothing - tight waistbands put pressure on your stomach
• Elevate your head while sleeping with an extra pillow or wedge

If you absolutely can’t manage the pain, talk to your OB/GYN before reaching for any pill. They can help you weigh the risks and benefits.

When to Call Your Doctor

Heartburn is normal. But some symptoms aren’t. Call your provider if you have:

• Heartburn that doesn’t improve with medication or lifestyle changes
• Difficulty swallowing or pain when swallowing
• Vomiting blood or black, tarry stools
• Unexplained weight loss
• Chest pain that radiates to your arm, jaw, or back

These could be signs of something more serious - like GERD complications, ulcers, or even heart issues. Don’t brush them off as “just pregnancy.”

What About Breastfeeding?

Good news: most of these medications are safe while breastfeeding. Calcium carbonate passes into breast milk in tiny amounts and won’t affect your baby. Famotidine and omeprazole also enter breast milk in very low levels, and no adverse effects have been reported in nursing infants. The American Academy of Pediatrics considers both safe for use during lactation.

Still, if you’re taking these long-term while nursing, keep an eye on your baby for unusual fussiness, diarrhea, or poor feeding. It’s rare, but worth noting.

Bottom Line: What to Do

- First trimester: Try lifestyle changes only. Avoid meds unless absolutely necessary. Talk to your provider.

- Second and third trimesters: Start with calcium carbonate antacids (Tums). If that’s not enough, move to famotidine (Pepcid). Only consider omeprazole if symptoms are severe and other options failed.

- Always: Check with your OB/GYN before taking anything - even something you think is “harmless.”

- Never: Use Pepto-Bismol, Zantac, or unapproved herbal remedies.

Heartburn doesn’t have to rule your pregnancy. With the right tools - and the right timing - you can find relief without risking your baby’s health. The safest path isn’t always the fastest one. But it’s the one that gets you to the finish line with both of you healthy.