Heartburn and Indigestion in Pregnancy

What is actually happening

Three things are going on at once, and the NHS names all of them: hormonal changes, the growing baby pressing on your stomach, and "the muscles between your stomach and gullet relaxing, allowing stomach acid to come back up." The HSE puts the hormonal part more precisely — "during pregnancy, hormones can relax the muscle that keeps your oesophagus closed" — and adds that "your growing baby can put pressure on your stomach. This can cause acid to move upwards into the oesophagus."

That combination explains the timing people find so odd. Heartburn often arrives late, or gets markedly worse late, because the mechanical part of the problem only builds as the bump does. The HSE reports that about 8 in 10 women have heartburn during pregnancy, and that "you're most likely to get heartburn in the third trimester (last 3 months) of your pregnancy."

The reassuring headline first, because it is worth having: the HSE states plainly that "heartburn is uncomfortable, but it does not harm you or your baby." Cochrane's reviewers describe it as one of the most common gut symptoms in pregnancy and note that serious complications are rare.

What it normally feels like

The NHS lists a burning sensation or pain in the chest, feeling bloated, burping, feeling sick and bringing food back up. Usefully, it also notes that "symptoms usually come on soon after eating or drinking, but there can sometimes be a delay" — which is why people often fail to connect a 9pm burning sensation with a 6pm meal.

The HSE separates the two words that get used interchangeably. Indigestion is "a bloated feeling you might have after eating or drinking"; heartburn is a type of indigestion, "a burning feeling, usually in your chest or throat." Other symptoms it lists include burping, stomach acid coming up into your mouth, feeling sick, being sick and tummy pain.

Common triggers named by the HSE: high-fat foods, spicy foods, chocolate, citrus products and caffeinated drinks.

What actually helps — and how strong the evidence is

This is where most articles overstate their case, so here is the honest version.

NICE's antenatal care guideline (NG201) makes two recommendations on heartburn. Recommendation 1.4.8 is to "give information about lifestyle and dietary changes"; recommendation 1.4.9 is to "consider a trial of an antacid or alginate for pregnant women with heartburn." Note the verb: consider. That is NICE's language for an option, not a strong recommendation, and it reflects how thin the underlying evidence is.

The Cochrane review of interventions for heartburn in pregnancy found only four small trials with usable data, covering 358 women in total. Its findings:

• Medication versus placebo or no treatment: women who received a pharmaceutical treatment reported complete relief more often (risk ratio 1.85, 95% CI 1.36 to 2.50; 256 women, two trials) — rated moderate-quality evidence.
• Partial relief and side effects: no clear difference, and the evidence was graded very low quality.
• Medication versus diet and lifestyle advice: in one trial of 65 women, more women taking sucralfate got complete relief than women given dietary and lifestyle advice (RR 2.41, 95% CI 1.42 to 4.07).
• Acupuncture: one trial of 36 women did not report heartburn relief at all, but found women reported improved ability to sleep (RR 2.80) and eat (RR 2.40).

The reviewers' own conclusion is blunt: "there is very little evidence to show that heartburn in pregnancy can be completely relieved by pharmaceutical treatment," and there is not enough data to say which medicine is best. So the practical advice below is worth trying because it is low-risk and widely recommended by national bodies — not because trials have shown it works well.

Things national guidance recommends

• Eat smaller amounts, more often rather than three large meals (NHS, HSE).
• Sit up straight while you eat and just after. The NHS explains why: "this will take the pressure off your stomach."
• Stop eating around three hours before bed. The HSE gives this as a specific figure.
• Prop your head and shoulders up in bed. The NHS says this "can stop stomach acid coming up while you sleep"; the HSE suggests pillows supporting head and shoulders.
• Cut back on caffeine and on rich, spicy or fatty foods (NHS).
• Avoid smoking and alcohol (NHS).
• Track your own triggers. Tommy's suggests noting what makes you feel worse and avoiding those foods, especially in the evenings — spicy foods, chocolate and fruit juice are common culprits.

Medicines

The two mainstream options are antacids, which the NHS describes as neutralising "the acid in your stomach", and alginates, which the HSE explains "stop the acid leaking back up from your stomach."

Two practical points that get missed:

• The NHS warns: "Do not take antacids within 2 hours of taking folic acid or iron supplements" — antacids interfere with absorption.
• The HSE is clear that not all antacids are safe in pregnancy: "tell your pharmacist that you're pregnant before taking medicine for indigestion and heartburn."

If over-the-counter options are not enough, this is a conversation for your midwife or doctor rather than a reason to keep buying stronger products.

When burning is not heartburn

This is the part of the page that matters most, and it is easy to miss because the symptom is so familiar.

Pain just below the ribs is one of the recognised symptoms of pre-eclampsia, and it is very commonly mistaken for indigestion. The NHS lists among the later symptoms of pre-eclampsia "pain below the ribs" alongside heartburn that does not go away with antacids. Its page on swelling in pregnancy says to seek immediate medical attention for a sudden increase in swelling of the face, hands or feet together with severe headaches, vision problems, rib pain, persistent heartburn or feeling severely unwell.

So the distinction is not really about how the burning feels. It is about what else is happening at the same time, and whether an antacid touches it.

When to call

Contact your maternity unit, midwife or doctor straight away — or your local urgent care line — if you have heartburn or upper tummy pain together with any of:

• A severe headache, or a headache that simple painkillers do not shift.
• Vision problems such as blurring or flashing lights.
• A sudden increase in swelling of your face, hands, feet or ankles.
• Vomiting, or feeling severely unwell.
• Heartburn that antacids do not relieve at all.

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, or 111 in New Zealand) if you collapse, have a seizure, or become severely breathless.

Book a non-urgent appointment with your midwife or doctor if: dietary and lifestyle changes are not working (NHS), or you have difficulty swallowing, a persistent cough, swollen neck glands, weight loss, repeated vomiting or stomach pain (NHS and HSE both list these). None of those are typical of ordinary pregnancy heartburn and they deserve a proper look.

What is worth letting go of

There is no evidence base behind the folk claim that heartburn predicts how much hair your baby will have, and there is no need to endure it on the grounds that it is "just part of pregnancy". Equally, there is no good trial evidence that any particular food elimination works for everyone — which is why the practical advice is to find your own triggers rather than adopt someone else's list wholesale.