Heartburn affects up to 80% of pregnant people, particularly in the second and third trimesters. It is caused by progesterone relaxing the valve between the stomach and oesophagus, combined with the growing uterus pushing the stomach upwards. Safe remedies include eating smaller meals, avoiding trigger foods, staying upright after eating, and taking antacids containing calcium carbonate or magnesium. Avoid antacids containing aluminium in high doses.
Heartburn (also called acid reflux or gastro-oesophageal reflux) is one of the most common pregnancy symptoms, affecting up to 80% of pregnant people at some point. It is a burning sensation in the chest and throat caused by stomach acid travelling back up the oesophagus.
Two factors work together to cause pregnancy heartburn:
Progesterone. This hormone relaxes smooth muscle throughout the body, including the lower oesophageal sphincter (the valve between your stomach and oesophagus). When this valve relaxes, stomach acid can escape upwards more easily.
Physical pressure. As the uterus grows, it pushes the stomach upwards and compresses it, which can force acid back into the oesophagus. This is why heartburn tends to get worse as pregnancy progresses and is most common in the third trimester.
Heartburn can start at any point during pregnancy but is most common from the second trimester onwards. It typically worsens in the third trimester as the baby grows and takes up more space. Some people experience it from very early pregnancy due to hormonal changes. For most people, heartburn resolves quickly after delivery once the physical pressure is relieved and hormone levels return to normal.
Eat smaller, more frequent meals. Large meals put more pressure on the stomach. Five or six smaller meals are easier to digest and reduce the likelihood of reflux.
Avoid trigger foods. Common triggers include spicy foods, citrus fruits and juices, tomatoes and tomato-based sauces, chocolate, fatty or fried foods, onions and garlic, and carbonated drinks. You may find that your personal triggers differ, so pay attention to what worsens your symptoms.
Stay upright after eating. Gravity helps keep stomach acid where it belongs. Avoid lying down for at least 2 to 3 hours after a meal. If heartburn is worst at night, try eating your evening meal earlier.
Elevate the head of your bed. Raising the head of your bed by 10 to 15 centimetres (using blocks under the bed legs, not extra pillows which can strain your neck) can reduce night-time reflux. Sleeping on your left side may also help, as this positions the stomach below the oesophagus.
Wear loose clothing. Tight clothes around the waist and abdomen can increase pressure on the stomach. Opt for loose, comfortable maternity wear.
Avoid eating and drinking at the same time. Drinking large amounts of fluid with meals can increase stomach volume. Sip fluids between meals instead.
Antacids. Over-the-counter antacids containing calcium carbonate (such as Rennie or Tums) or magnesium hydroxide are generally considered safe during pregnancy. They work by neutralising stomach acid and provide quick relief. The NHS recommends these as first-line treatment.
Alginates. Products like Gaviscon contain alginates that form a raft on top of stomach contents, preventing acid from rising. Gaviscon is considered safe in pregnancy and many people find it effective, particularly for night-time reflux.
Avoid: Antacids containing high doses of aluminium, as these may cause constipation. Avoid sodium bicarbonate (baking soda) as it can cause water retention. If in doubt, check with your pharmacist.
Prescription options. If antacids are not sufficient, your GP may prescribe ranitidine alternatives (ranitidine was withdrawn in 2020) such as omeprazole or lansoprazole. These are proton pump inhibitors (PPIs) and are considered safe in pregnancy when prescribed by a doctor. NICE guidelines support their use when lifestyle changes and antacids are inadequate.
Milk. A glass of cold milk can provide temporary relief by coating the oesophagus, though it may worsen symptoms for some people in the longer term as milk stimulates acid production.
Ginger. Ginger tea may help with both nausea and mild heartburn. It has anti-inflammatory properties and can aid digestion.
Yoghurt. Plain yoghurt can soothe the oesophagus and may help neutralise acid. It is also a good source of calcium and protein.
Almonds. Some people find that chewing a small handful of almonds after a meal helps reduce heartburn, possibly because almonds are alkaline.
Speak to your GP or midwife if heartburn is not relieved by antacids or lifestyle changes, you are losing weight because of difficulty eating, you have difficulty swallowing, you are vomiting blood or have blood in your stools, or you have severe upper abdominal pain (particularly on the right side, which could indicate pre-eclampsia rather than heartburn).
Yes. Heartburn typically worsens as pregnancy progresses because the growing uterus pushes the stomach upwards, increasing pressure and making acid reflux more likely.
Yes, Gaviscon is considered safe during pregnancy. It contains alginates that form a protective barrier on top of stomach contents, preventing acid reflux.
No. Pregnancy heartburn is uncomfortable for you but does not affect your baby. However, if it prevents you from eating properly, speak to your midwife about management.
Antacids containing calcium carbonate (Rennie, Tums) or magnesium hydroxide are generally safe. Avoid high-dose aluminium antacids and sodium bicarbonate. Check with your pharmacist.
Yes, for most people heartburn resolves quickly after delivery as the physical pressure on the stomach is relieved and progesterone levels return to normal.
Milestones, partner sharing, notes, photos, and a curated essentials guide. Free, no app to install.
Get Started Free© 2026 Nuhah. All rights reserved.