Heartburn in pregnancy affects the majority of women, and it is treated as one of those minor inconveniences you are simply meant to put up with. Which is easy to say when you are not the one lying awake at two in the morning with a burning chest, propped on four pillows, unable to get comfortable in any position at all.
It is genuinely miserable, particularly in the last few months when it tends to be at its worst. Here is why it happens, what actually helps, and one specific symptom that is worth taking seriously rather than assuming is just reflux.
Why heartburn in pregnancy is so common
Estimates vary, but somewhere between forty and eighty per cent of women experience it at some point in pregnancy. It is one of the most common complaints there is, and yet it is rarely discussed with any real practical detail.
Part of the problem is that it gets bundled in with the general expectation of discomfort. You are pregnant, so of course you are uncomfortable. But heartburn affects sleep, and sleep affects everything else, so it is worth addressing properly rather than enduring.
What is actually happening
Two things, working together.
Progesterone relaxes smooth muscle. This is genuinely useful in pregnancy, since it keeps your uterus from contracting. But it does not act selectively. It also relaxes the lower oesophageal sphincter, the ring of muscle at the top of your stomach that normally keeps stomach contents where they belong. When that valve is more relaxed than usual, acid travels upwards.
Progesterone also slows the rate at which your stomach empties, so food sits there longer, giving it more time and opportunity to reflux.
Your growing uterus presses upward. As your baby grows, everything above gets compressed. Your stomach has less room, sits higher, and is under more physical pressure, which pushes contents towards a valve that is already less competent than usual.
So it is a mechanical problem and a hormonal one at once, which is exactly why it worsens as pregnancy progresses.
When it usually starts, and whether it eases
Honestly, the timeline is not especially encouraging, but knowing it helps you plan.
It can begin at any point, and some women experience it from the first trimester, driven by progesterone before there is any real bump. More commonly it appears in the second trimester and worsens through the third.
It typically peaks in the third trimester, when the mechanical pressure is greatest. Many women find the last six to eight weeks are the hardest.
Some women get relief when the baby drops lower into the pelvis in the final weeks, which takes some pressure off the stomach. Others find no such reprieve.
The genuinely good news is that it resolves almost immediately after birth, since both the progesterone and the pressure disappear at once. This is one of the few pregnancy complaints with a genuinely clean ending.
What genuinely helps at mealtimes
The mechanical changes are where most of the improvement comes from, and they cost nothing.
Eat smaller amounts more often. This is the single most effective change. A large meal distends a stomach that already has no room and increases pressure against a relaxed valve. Five or six smaller meals across the day works considerably better than three substantial ones.
Eat slowly. Rushing means swallowing more air and arriving at fullness before you have noticed. Putting your cutlery down between mouthfuls sounds fussy but genuinely helps.
Stay upright for two to three hours afterwards. Lying down or reclining removes gravity from the equation entirely. If you need to rest, do it propped up rather than flat.
Do not eat within about three hours of bed. This is the one that most improves nights. It is inconvenient, particularly if you are hungry in the evening, but shifting your main meal earlier and having something small rather than substantial later makes a real difference.
Drink between meals rather than with them. Fluid alongside food adds volume to an already crowded stomach. Sip through the day instead.
Loosen your waistband. Anything pressing on your abdomen adds to the pressure. Maternity clothing with a soft over-bump panel is worth it for this reason alone.
Chewing gum after meals stimulates saliva, which is alkaline and helps neutralise acid. A small thing with a reasonable evidence base.
Trigger foods, and why the standard list may not be yours
You will find a standard list everywhere: citrus, tomatoes, spicy food, fried food, chocolate, caffeine, fizzy drinks, mint.
Those are common triggers, and they are worth knowing. But here is the more useful point: your triggers may not match the list at all, and cutting all of them pre-emptively narrows your diet considerably at a time when eating well matters.
A more sensible approach is to notice your own pattern. Keep a rough note for a week or two of what you ate and when the burning was worst. Most women find two or three specific culprits rather than the whole list, and knowing yours means you can eat everything else freely.
Some women find mint helps, despite it appearing on trigger lists, since it relaxes the valve for some and soothes for others. This is exactly why individual observation beats a generic list.
What is worth being cautious with regardless is very large, very fatty meals, since fat slows stomach emptying further, and eating late.
If digestion generally has been sluggish, our article on gut health covers the wider picture, and steady blood sugar helps too, since erratic eating tends to mean larger meals when you finally do eat.
Sleeping without the burn
Nights are usually the worst of it, and a few things genuinely change that.
Prop yourself up. Not just extra pillows under your head, which tends to bend you at the neck and does little. Raise the whole upper half of your body, either with a wedge pillow or by putting something under the legs at the head of the bed to tilt the whole mattress. Gravity does the work.
Sleep on your left side. This has a genuine anatomical basis: your stomach sits to the left, and lying on that side keeps the junction with your oesophagus above the level of the stomach contents. Lying on the right does the opposite. Conveniently, left side sleeping is also recommended in later pregnancy for blood flow, so it serves two purposes.
Time your last meal. Three hours before lying down, as above. This matters more than almost anything else for night symptoms.
Have something small to hand in case you wake, since an empty stomach can sometimes make it worse. A few plain crackers or a small glass of milk.
Accept that a pregnancy pillow is worth the money if you are struggling. Supporting the bump and keeping you on your side, propped up, makes the whole arrangement more sustainable.
What is safe to take
There are effective options, and you do not have to simply endure this.
Antacids and alginates are commonly used in pregnancy, and several are considered suitable. If those are not enough, there are further options your GP or midwife can prescribe, and these are used routinely in pregnancy where symptoms are significant.
Please speak to your pharmacist, GP or midwife rather than taking anything you happen to have in the cupboard or that a friend recommends. Pharmacists in particular are genuinely helpful for this and you do not need an appointment.
One practical note: if you are taking iron supplements, be aware that antacids interfere with iron absorption, so leave a gap of a couple of hours between them.
When heartburn is not heartburn
This section matters more than anything else in this article, so please do read it.
Pain under your ribs on the right side, or in the upper right of your abdomen, is not typical heartburn and should always be checked.
In later pregnancy, particularly from around twenty weeks onwards, this kind of pain can be a sign of pre-eclampsia, a serious condition affecting the placenta and your blood pressure. The pain is often described as being under the ribs, sometimes mistaken for indigestion or heartburn, and it is a symptom that is very frequently dismissed by women who assume it is just reflux.
Contact your maternity team or triage immediately, the same day, if you have:
- Pain under your ribs, particularly on the right side
- A severe or persistent headache that does not settle
- Visual disturbances, flashing lights, blurred vision or spots
- Sudden swelling of your face, hands or feet
- Feeling generally unwell or unusually anxious, alongside any of the above
- Vomiting in later pregnancy that is new
You do not need several of these. Any one of them warrants a call, and pain under the ribs alongside a headache or visual changes warrants an urgent one.
Please do not worry about wasting anyone’s time. Maternity triage would far rather assess you and find nothing than miss pre-eclampsia, which can develop quickly and is why blood pressure and urine are checked at every appointment.
Ordinary heartburn is a burning sensation behind the breastbone, often rising towards the throat, usually related to eating or lying down, and typically relieved by antacids. Pain that sits under the ribs, does not relate to meals, and is not relieved by antacids is a different thing and needs assessing.
What to hold onto
Heartburn in pregnancy is common, genuinely miserable, and more manageable than it feels at two in the morning.
Smaller meals more often, nothing within three hours of bed, upright after eating, propped up and on your left side at night, and a conversation with your pharmacist about what is safe to take. Notice your own triggers rather than cutting everything on a generic list.
And know the difference between the burning you can manage and the pain under your ribs that needs a phone call. That distinction is the most important thing in this article.
It ends the day your baby arrives, which is not much consolation at three in the morning but is at least genuinely true.
A gentle note
If you would love practical support feeling more comfortable through your pregnancy, I am here. I offer warm, one-to-one pregnancy coaching alongside your midwifery care.
Written by
Brydee Thomas
Holistic health coach and founder of Radiant Bloom, supporting women through trying to conceive, pregnancy and the postpartum months. Evidence-based guidance, no programmes and no generic plans.