Heartburn in Pregnancy: What Helps, Safe Antacids and Relief at Night

How do you relieve heartburn during pregnancy?

To relieve heartburn in pregnancy, start by changing how and when you eat, which the NHS says may be enough if symptoms are mild; if it is not, there are antacids that are safe in pregnancy. The NHS suggests eating small meals often instead of three large ones, sitting up straight while you eat and just afterwards, and not eating within 3 hours of going to bed.

A 2022 review in BMC Gastroenterology on heartburn in pregnancy says lifestyle and diet changes should be advised first and help most people. Its list of common triggers includes fatty or spicy foods, chocolate, mints, caffeinated drinks, citrus juices, tomatoes and fizzy drinks, and it suggests a food diary to find yours. The review also suggests drinking fluids between meals and less with them, and chewing gum to neutralize acid.

The NHS says cutting down on caffeine and on rich, spicy or fatty foods can ease symptoms, and that smoking and alcohol can both cause indigestion. ACOG's general advice on acid reflux adds not lying on your back right after eating.

Why does heartburn happen in pregnancy?

Heartburn is more likely in pregnancy because of hormonal changes and the growing baby pressing on your stomach, the NHS says, along with the muscles between the stomach and the esophagus relaxing and letting stomach acid come back up. The BMC review adds slower movement of food through the gut and weight gain as pregnancy goes on.

The NHS says symptoms can start at any point in pregnancy but are more common from 12 weeks onwards. You are more likely to get heartburn if you had indigestion before pregnancy, have been pregnant before, or are in the later stages of pregnancy, according to the NHS. The BMC review says reflux becomes more common from the first trimester to the third, and that its prevalence in pregnancy has been reported as high as 80% in some populations.

The NHS lists the symptoms as a burning feeling or pain in the chest, feeling full, heavy or bloated, burping, feeling or being sick, and bringing food back up, usually soon after eating or drinking. The BMC review says symptoms typically go away after birth, although about 20% of women still have them afterwards.

Why is heartburn worse at night?

Heartburn can be worse at night because reflux can become more frequent when you lie down, ACOG says in its general advice on acid reflux. The NHS says propping up your head and shoulders in bed can stop stomach acid coming up while you sleep, and that sleeping on your left side can also help.

The BMC review recommends raising the head of the bed by 4 to 6 inches (10 to 15 cm), lying on your left side rather than your right side or your back, and not eating within 3 hours of going to bed. It notes that the biggest effect of reflux on quality of life is on sleep. Which side to sleep on in later pregnancy, and why, is in the safest sleeping position during pregnancy.

Can you take Tums or other antacids while pregnant?

Calcium carbonate, the active ingredient in Tums, is the preferred antacid in pregnancy according to a 2023 review in American Family Physician, used within the usual dose limits. Check with your doctor, midwife or pharmacist before taking any antacid. The NHS lists antacids and alginates as medicines for heartburn in pregnancy and says to tell the pharmacist you're pregnant, because some antacids are not suitable.

American Family Physician says to avoid antacids containing sodium bicarbonate, which can cause fluid overload and metabolic alkalosis in the mother or the baby, and antacids with magnesium trisilicate. The BMC review links long-term use of magnesium trisilicate to heart and breathing problems and kidney stones. Other aluminum and magnesium antacids are acceptable, according to American Family Physician.

The BMC review warns that excessive use of calcium antacids can cause calcium-alkali syndrome, with high blood calcium, metabolic alkalosis and kidney problems, and says pregnant women need guidance to avoid an overdose. MedlinePlus, which lists Tums among its calcium carbonate brands, says not to take calcium carbonate as an antacid for more than 2 weeks unless your doctor tells you to, and to tell your doctor if you are pregnant. American Family Physician also says products containing bismuth subsalicylate should be avoided after 20 weeks because of risks to the baby, including kidney problems and low amniotic fluid.

The NHS says not to take antacids within 2 hours of folic acid or iron supplements, because antacids can stop your body absorbing them. Prenatal vitamins covers what those supplements should contain.

What if antacids don't help your heartburn?

See your doctor or midwife: the NHS says that if antacids and alginates don't improve your symptoms, a GP may prescribe a medicine that reduces the amount of acid in your stomach. American Family Physician says H2 antihistamines (H2 blockers) and proton pump inhibitors (PPIs) are safe options when calcium carbonate does not control symptoms, and its table lists PPIs as acceptable in the second and third trimesters.

American Family Physician also notes that a 2020 meta-analysis suggested a possible increased risk of birth defects and asthma in children exposed to PPIs before birth, but that weaknesses in the studies rule out declaring a definite link. ACOG's general advice on acid reflux says that reflux more than twice a week, or 2 weeks of over-the-counter treatment with no relief, may mean gastroesophageal reflux disease (GERD).

If you take a prescription medicine for another condition and think it is making indigestion worse, the NHS says to speak to your GP, and never to stop a prescribed medicine without advice from your GP or the professional responsible for your care.

When should you call your doctor or midwife?

The NHS lists heartburn that does not go away with heartburn medicines and pain below the ribs among the symptoms of preeclampsia that need checking immediately, and says preeclampsia is most likely from 20 weeks but can happen at any point in pregnancy. The NHS also says pain just under the ribs is common in later pregnancy as the baby and uterus push up, but that pain there which is bad or persistent, particularly on the right side, can be a sign of preeclampsia. Preeclampsia symptoms covers the other signs.

Call your doctor or midwife about:

• Heartburn that heartburn medicines don't ease, bad or lasting pain under the ribs, or feeling very unwell (NHS).
• Pain in the upper belly or shoulder, nausea and vomiting in the second half of pregnancy, a headache that won't go away, changes in eyesight, swelling of the face or hands, sudden weight gain, or difficulty breathing (ACOG).
• Difficulty swallowing, a hoarse voice, a cough that doesn't get better or keeps coming back, swollen glands on either side of your neck, weight loss, or pain or swelling in your stomach (NHS).
• Symptoms that diet and lifestyle changes don't control (NHS).