Heartburn in Pregnancy: What’s Safe to Take and What Helps
Why pregnancy causes heartburn, the safe treatment ladder from food tweaks to Gaviscon to omeprazole, and relief tips by trimester.
Part of the Complete Acid Reflux Guide.
Key fact: Heartburn affects up to 8 in 10 pregnancies — and it can be treated safely. Alginates like Gaviscon are first choice throughout pregnancy, with omeprazole a well-evidenced option where more is needed.
Talk to a Prescriber About Pregnancy Heartburn
Pregnancy prescribing deserves a careful conversation, not a hard sell. Our pharmacist independent prescribers can review your symptoms and advise what is safe for you and your baby.
Speak to a Prescriber →Why pregnancy causes heartburn
Two forces work together. First, progesterone — the hormone that maintains pregnancy — relaxes smooth muscle throughout the body, including the valve (the lower oesophageal sphincter) that normally keeps stomach acid out of the oesophagus. Second, as the uterus grows it exerts direct upward pressure on the stomach, pushing contents against that already-relaxed valve. Neither is anything you did wrong, and neither harms your baby — but together they explain why heartburn is one of the most common complaints of pregnancy.
When it starts — and when it eases
Heartburn can appear at any stage. In early pregnancy the cause is mostly hormonal; from around 27 weeks the mechanical pressure of the growing baby takes over and symptoms typically peak. For most women it does not fully settle until after the birth — but it then usually resolves quickly, as hormone levels fall and the pressure lifts. Persistent reflux after delivery is worth mentioning to your GP, as it suggests something other than pregnancy was contributing.
Safe first steps (no medicines needed)
These changes are safe for everyone and often enough on their own in early pregnancy:
- Smaller, more frequent meals — a crowded stomach has nowhere to go but up, especially with a baby pressing from below.
- Eat slowly and sit upright during and after meals — give gravity every chance to help.
- Finish eating 2–3 hours before lying down — the single most effective habit for evening and night symptoms.
- Identify your triggers — fatty and spicy food, chocolate, citrus, tomato and fizzy drinks are the usual culprits. Our foods to avoid guide covers them all.
- Cut caffeine — already advised in pregnancy, and it relaxes the reflux valve too.
- Loose clothing — anything tight around the waist adds to the pressure.
The safe medicines ladder
UK guidance follows a simple step-up approach. Start at the bottom; move up only if the step below is not enough.
1
Alginates (Gaviscon, Gaviscon Advance) — first choice
Alginates form a physical raft that floats on the stomach contents and blocks reflux. Because they act in the stomach rather than being absorbed into the bloodstream, they are considered safe throughout pregnancy. Take after meals and at bedtime. Simple antacids (calcium or magnesium based, such as Rennie) are also considered safe when used as directed.
2
Omeprazole — when alginates aren’t enough
Among proton pump inhibitors, omeprazole has the most extensive pregnancy safety evidence, accumulated over decades of use, and is the standard choice for persistent pregnancy heartburn. It should be started after discussion with your midwife, GP or a prescriber.
3
Review if symptoms persist
Heartburn that does not respond to the ladder, or that comes with red-flag symptoms, needs a proper clinical review rather than escalating doses.
Breastfeeding note: Gaviscon and omeprazole are both considered compatible with breastfeeding, so treatment does not have to stop at delivery — though for most women, so does the heartburn.
What to avoid in pregnancy
- Bicarbonate of soda (baking soda) — the sodium load can cause fluid retention, unhelpful in pregnancy.
- Effervescent remedies containing aspirin — aspirin at analgesic doses is not recommended in pregnancy; always check labels.
- Unlicensed herbal remedies — safety in pregnancy is largely untested; run anything herbal past a pharmacist first.
- Timing clashes with iron tablets — antacids and alginates can block iron absorption. Separate them by at least two hours.
Night-time heartburn when pregnant
Lying down removes gravity from the equation just as the pressure on your stomach peaks. The fixes that work: an alginate dose at bedtime, the head of the bed raised 10–15cm on blocks (not just extra pillows, which bend you at the waist), your last meal 2–3 hours before bed, and sleeping on your left side — which happily is the same position midwives recommend from 28 weeks for blood flow to your baby. Left-side sleeping also positions the stomach’s entrance above the acid pool, reducing reflux.
When to talk to your midwife or GP
Pregnancy heartburn is common and benign, but some symptoms need a proper look:
Book a review if heartburn is not controlled by the ladder above, if you have difficulty swallowing, are losing weight, or vomiting persistently (severe vomiting in pregnancy needs assessment in its own right).
Call your maternity unit urgently if you develop pain just under the ribs on the right or centre in the second half of pregnancy — especially with headache, vision changes or sudden swelling of face, hands or feet. This can be pre-eclampsia, which is sometimes mistaken for heartburn. Chest pain with breathlessness or pain spreading to your arm or jaw: call 999.
Persistent Pregnancy Heartburn? Get Proper Advice
If lifestyle changes and Gaviscon aren’t enough, our pharmacist independent prescribers can review your symptoms and discuss safe next steps — honestly, including when we’d rather you saw your midwife or GP.
Start Your Consultation →Frequently Asked Questions
Is Gaviscon safe in pregnancy?
Yes. Alginates such as Gaviscon are the recommended first-line medicine for pregnancy heartburn in the UK. They work physically — forming a protective raft on top of the stomach contents — rather than being absorbed into the body, which is why they are considered safe throughout pregnancy. Take a dose after meals and at bedtime for the best effect.
Can I take omeprazole while pregnant?
Yes, where it is needed. Omeprazole has been used in pregnancy for decades and has extensive reassuring safety data, which is why it is the usual choice when lifestyle changes and alginates are not enough. It should be started after a conversation with your midwife, GP or a prescriber rather than self-treating — pregnancy prescribing deserves that extra check.
When does pregnancy heartburn start and will it go away?
It can begin at any stage, but it typically appears or worsens from the second trimester and peaks in the third, when the growing uterus presses directly on the stomach. The good news is that pregnancy heartburn almost always resolves quickly after birth as hormone levels fall and the pressure lifts.
Does heartburn in pregnancy mean my baby will have lots of hair?
Remarkably, a small Johns Hopkins study did find that women with worse heartburn had hairier babies on average — the researchers suggested the same pregnancy hormones that relax the valve above the stomach also influence fetal hair growth. It is a genuine correlation but a weak one, so treat it as a fun story rather than a prediction.
How can I stop pregnancy heartburn at night?
Finish eating two to three hours before bed, take a dose of an alginate like Gaviscon at bedtime, raise the head of the bed 10 to 15 centimetres with blocks under the legs, and sleep on your left side — which is also the side midwives recommend in later pregnancy for blood flow. Extra pillows alone tend to bend you at the waist and can make reflux worse.
What heartburn remedies should I avoid in pregnancy?
Avoid bicarbonate of soda (the sodium load can cause fluid retention), any remedy containing aspirin such as some effervescent products, and unlicensed herbal remedies whose safety in pregnancy is unknown. Check with a pharmacist before taking anything new — and mention any iron tablets you take, as antacids can stop iron being absorbed if taken at the same time.
Support from Access Doctor
Pregnancy heartburn usually responds well to the safe options above. Where prescription treatment is appropriate, Access Doctor’s pharmacist independent prescribers take pregnancy into account in every clinical assessment — and will always tell you when your midwife or GP is the better route.
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View product →References
- National Institute for Health and Care Excellence. Clinical Knowledge Summary: Dyspepsia — pregnancy-associated. 2023. cks.nice.org.uk
- NHS. Indigestion and heartburn in pregnancy. 2023. nhs.uk
- UK Teratology Information Service. Use of omeprazole in pregnancy. medicinesinpregnancy.org
- Pasternak B, Hviid A. Use of proton-pump inhibitors in early pregnancy and the risk of birth defects. New England Journal of Medicine. 2010. pubmed.ncbi.nlm.nih.gov
- Costigan KA, Sipsma HL, DiPietro JA. Pregnancy folklore revisited: the case of heartburn and hair. Birth. 2006. pubmed.ncbi.nlm.nih.gov
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.