Safe Antacids in Pregnancy: What Works and What to Avoid

When you're pregnant, heartburn isn't just annoying—it can feel like your stomach is trying to escape through your throat. That burning feeling? It's heartburn in pregnancy, a common condition caused by hormonal changes and pressure from the growing uterus pushing stomach acid upward. It affects up to 80% of pregnant women, especially in the second and third trimesters. Many reach for over-the-counter antacids, but not all are safe. Knowing the difference can make all the difference for you and your baby.

The safest options are those with simple, well-studied ingredients like calcium carbonate, a common antacid found in brands like Tums that neutralizes acid and adds extra calcium—a bonus since you need more calcium during pregnancy. Another safe choice is magnesium hydroxide, often paired with aluminum hydroxide in products like Maalox, which works quickly and doesn’t cross the placenta in harmful amounts. These are the go-tos for OB-GYNs and pharmacists who’ve seen what actually works without risk.

But avoid anything with sodium bicarbonate (baking soda)—it can cause fluid overload and affect your baby’s pH balance. Stay away from aluminum-based antacids used long-term, as they can build up in your system. And never mix antacids with iron supplements without spacing them out—calcium blocks iron absorption, which you need for your baby’s blood supply. If you’re taking prenatal vitamins, check the label. Some already include calcium, so you might not need extra.

What you eat matters too. Spicy food, caffeine, and big meals right before bed make heartburn worse. Eating smaller meals, staying upright for an hour after eating, and sleeping with your head slightly raised can cut symptoms by half. Sometimes, the simplest fix isn’t a pill—it’s a change in routine.

When in doubt, talk to your provider before taking anything—even something that seems harmless. What’s safe for one person might not be right for another, especially if you have gestational diabetes, high blood pressure, or kidney issues. Your body’s changing fast, and what worked before pregnancy might not be safe now.

The posts below give you real-world advice from people who’ve been there: which antacids worked without side effects, how to spot the ones to avoid, and what alternatives like ginger or chamomile tea actually help. You’ll find comparisons, dosing tips, and stories from moms who figured out their own safe routine. No fluff. Just what you need to feel better without risking your pregnancy.