Heartburn is most common in late pregnancy, particularly after 36 weeks. This is because of the increased pressure of your fetus on your stomach as you near the end of pregnancy.

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Heartburn is a common pregnancy discomfort, affecting up to 80% of expectant parents. Sometimes referred to as acid reflux or indigestion, heartburn in pregnancy is caused by hormonal changes and increased pressure of the growing fetus pressing against your stomach.

It’s most prevalent in the third trimester of pregnancy and is usually most bothersome at 36 weeks of pregnancy or later, as your baby reaches their largest weight and size before birth.

If heartburn in late pregnancy is a challenge for you, you aren’t alone. Here’s what heartburn at 36 weeks or later looks like and how you can get some much-needed relief.

The hormones of pregnancy can cause digestion to become sluggish and can also relax the muscles in the digestive system, triggering food and stomach acid to be regurgitated back up your esophagus. Not only that, but the pressure of the baby and your growing uterus against the stomach can cause heartburn symptoms.

These symptoms may worsen as your pregnancy progresses, particularly when you reach 36 weeks. At 36 weeks pregnant, your baby weighs about 6 pounds, is about 18 inches long, and will continue to grow rapidly over the next few weeks. By 40 weeks pregnant, your baby is 7 to 8 pounds and about 20 inches long. That’s a lot of pressure on your stomach and digestive system!

Heartburn in late pregnancy can be extremely uncomfortable, and is often worse at night, just when you want to finally get some rest. That’s because lying down flat makes it easier for your stomach acid to pool in your esophagus. Symptoms may also be worse right after you’ve eaten.

Some of the most common symptoms of heartburn in late pregnancy include:

Usually, your doctor and midwife can diagnose heartburn based on the description of your symptoms. If they are concerned that your symptoms are caused by something other than heartburn, a more thorough examination may be necessary.

For the most part, heartburn is more bothersome and uncomfortable than anything else. But occasionally, it may make it difficult for you to eat. If you’re having trouble eating, keeping food down, or are losing weight, contact your healthcare professional promptly.

Heartburn in the third trimester can make it difficult to eat, exercise, work, and sleep. However, there are effective treatment options so you can feel more like yourself.

Medical treatment

When you’re pregnant, you have to be cautious about what medications you take. While some heartburn medication is not considered safe during pregnancy, there are several safe options, but talk with your doctor or midwife before taking any medication during pregnancy.

Here are a few options for treating heartburn while pregnant:


Antacids made of substances like calcium, magnesium, and aluminum are the best choice during pregnancy. They work by neutralizing stomach acids and are considered safe during pregnancy.

However, most doctors recommend avoiding antacids made with sodium bicarbonate, as these can cause fluid retention and may lead to other health problems during pregnancy. Antacids containing bismuth subsalicylate are also not recommended during pregnancy.


Alginates are medications that create a gel barrier at the top of your stomach contents so that stomach acids aren’t able to leak. Alginates are often combined with antacids for relief. Most alginates are safe to use in pregnancy. But always check with a doctor before starting any medications.

At-home tips for relieving heartburn in late pregnancy

Heartburn during pregnancy can often be managed with simple tweaks to your daily routine and sleeping setup.

Here are a few tips:

  • eat smaller, more frequent meals
  • try to avoid eating within about 3 hours before you go to sleep
  • stay upright after eating
  • prop your head and shoulders up while sleeping
  • stick to blander foods for now
  • avoid alcohol and caffeine
  • avoid smoking

Although heartburn can affect your sleep, productivity, and quality of life, it rarely causes complications.

A main concern is if the condition makes it difficult for you to eat or drink and causes reduced caloric intake or dehydration. If that’s the case for you, speak with your healthcare professional for treatment options.

Most of the time, heartburn symptoms will resolve after you deliver your baby. However, some people may have symptoms that linger.

If your symptoms linger, follow up with your doctor, healthcare professional, or GI specialist. Heartburn after pregnancy may be a sign that the lower esophageal sphincter is widening and becoming a more permanent concern that may need additional treatment.

What foods trigger heartburn in late pregnancy?

Trigger foods for heartburn include greasy or fried foods, acidic foods like fruit and tomato sauce, fatty foods, chocolate, spicy foods, and foods containing garlic and onions.

How common is heartburn in pregnancy?

While heartburn is most common in late pregnancy, you may experience it at other stages of pregnancy as well. According to a 2015 review of 80 studies, about 22% of people experience it in the first trimester, 39% experience it in the second trimester, and up to 72% experience it in the third trimester.

Does exercise help with heartburn?

Yes! Exercise — particularly an upright activity like walking — can help you digest your food and also decrease your stress, both of which can help with heartburn.

Heartburn during pregnancy is common, especially as you reach 36 weeks and later towards the end of pregnancy. The pressure of the fetus against your stomach increases symptoms.

Heartburn can be extremely uncomfortable, disrupt your life, and make sleeping challenging. But lifestyle changes can make a difference, and many heartburn medications are safe to use during pregnancy. Contact your doctor or midwife for treatment options to help relieve your symptoms.