Tums Pregnancy: Safe Antacids and What to Avoid During Pregnancy

When you're pregnant, heartburn isn't just annoying—it can feel constant. Tums, a common over-the-counter antacid made from calcium carbonate. Also known as calcium carbonate tablets, it's one of the most trusted options for quick relief during pregnancy because it neutralizes stomach acid without crossing the placenta. Many OB-GYNs recommend it because it’s not absorbed into the bloodstream the way some other medications are. But not all antacids are the same, and knowing what’s safe—and what to skip—can make a big difference in how you feel day to day.

Heartburn during pregnancy happens because hormones relax the muscle that keeps acid down, and as your baby grows, it pushes up on your stomach. That’s why symptoms often get worse in the second and third trimesters. Calcium carbonate, the active ingredient in Tums, works fast by directly neutralizing acid. It also gives you a little extra calcium, which your body needs more of during pregnancy. But too much calcium can cause constipation or kidney stones, so sticking to the recommended dose—usually 2 to 4 tablets a day—is key. Don’t crush, chew, or take more than your doctor suggests, even if you’re feeling worse than usual.

Other antacids like Maalox or Mylanta contain aluminum or magnesium, which aren’t harmful in small doses but can build up if you use them daily over weeks. Magnesium-based antacids might also trigger early contractions in high amounts. Then there’s sodium bicarbonate, found in baking soda and some antacids, which you should avoid—it can cause fluid retention and raise your blood pressure, both risky during pregnancy. Even though Tums is generally safe, it’s not a cure-all. If you’re still burning after a week of use, or if you’re having trouble keeping food down, talk to your provider. You might need something stronger, like a PPI or H2 blocker, which are also considered safe under supervision.

Some women worry that using Tums every day means they’re dependent on it. That’s not true. It’s not addictive. But if you’re relying on it daily, it might mean your heartburn is being triggered by something else—like eating too fast, lying down after meals, or eating spicy or fatty foods. Simple changes—eating smaller meals, staying upright for an hour after eating, and avoiding trigger foods—can reduce how often you need it. And if you’re taking a prenatal vitamin with iron, that can make heartburn worse. Try taking your iron at night instead of with meals.

What you’ll find in the posts below are real, practical insights from people who’ve been there and from experts who know what works. You’ll see how Tums pregnancy fits into the bigger picture of managing nausea, acid reflux, and medication safety during each trimester. There’s also guidance on what other antacids are safe, how to spot warning signs, and when to call your doctor instead of reaching for another tablet. This isn’t just about pills—it’s about understanding your body, knowing your limits, and making smart choices so you can feel better without risking your health or your baby’s.