Acid reflux and heartburn during pregnancy: the complete guide

By: Dr Elie Servan-Schreiber (Gynécologue-obstétricien) — 11/03/2020

If you are pregnant and feel a burning sensation rising in your chest after meals, you are not alone. Acid reflux during pregnancy is one of the most common discomforts, especially from the second trimester onward. Good news: there are many practical solutions to reduce it. This comprehensive guide explains why it occurs, how to adapt your diet, which treatments are allowed, and when to see a doctor.

What is gastroesophageal reflux (GER)?

Gastroesophageal reflux, or GER, refers to the backflow of acidic stomach contents into the esophagus. Normally, a ring-shaped muscle called the lower esophageal sphincter (LES) acts as a one-way valve: it opens to let food pass into the stomach, then closes to prevent gastric contents from rising back up. When this sphincter relaxes inappropriately or abdominal pressure increases, stomach acid flows back into the esophagus, causing the characteristic burning sensation.

A distinction is made between physiological GER — brief and infrequent episodes, often after a large meal — and pathological GER, which manifests through regular, intense symptoms that impair quality of life. During pregnancy, GER is primarily physiological: it is directly related to the hormonal and mechanical changes specific to this period. It resolves in the vast majority of cases after delivery.

Why is acid reflux so common during pregnancy?

Three main factors explain why gastric reflux during pregnancy is so common. These mechanisms act synergistically and intensify as the trimesters progress.

1. Progesterone: the hormonal factor

Progesterone, an essential hormone for maintaining pregnancy, sees its concentration increase tenfold over the course of nine months (Richter, 2005). Its primary role is to relax the smooth muscles of the uterus to prevent premature contractions. But this muscle-relaxing effect is not limited to the uterus: it also affects the lower esophageal sphincter. Studies show that the LES relaxes by 30 to 50% under the effect of progesterone (Ali and Egan, 2007), which reduces its ability to prevent acid reflux. This relaxation explains why GER can appear as early as the first trimester in some women, well before the uterus exerts significant mechanical pressure.

2. The mechanical pressure of the uterus

As the baby grows, the uterus takes up more and more space in the abdominal cavity. In the third trimester, it exerts direct pressure on the stomach, pushing it upward and reducing its available volume. This compression increases intragastric pressure and promotes the backflow of acidic contents into the esophagus. This is why heartburn during pregnancy worsens significantly in late pregnancy and is particularly intense when lying down or bending forward.

3. Slower gastric emptying

Progesterone also slows gastrointestinal motility overall. Stomach emptying time is prolonged, meaning food stays in the stomach longer. This slowdown increases gastric volume, acid production, and the likelihood of reflux. It also contributes to the feeling of heaviness and bloating that is common during pregnancy.

Symptoms of gastroesophageal reflux during pregnancy

The symptoms of pregnancy GER vary and can range from mild discomfort to significant distress. Recognizing them helps to adapt relief measures and distinguish reflux from other more concerning conditions.

Classic GER symptoms

• Retrosternal burning (pyrosis): a burning sensation behind the breastbone, sometimes rising to the throat. This is the most common and characteristic symptom.
• Acid regurgitation: backflow of acidic liquid or partially digested food into the mouth, without effort to vomit.
• Bitter or sour taste in the mouth: often present upon waking or after a meal.
• Nighttime cough: a persistent dry cough, especially when lying down, can be a sign of reflux. The acidic contents irritate the upper airways.
• Chest pain: sometimes confused with cardiac pain, GER-related pain is worsened by meals and lying down.
• Feeling of a lump in the throat: called "globus," this sensation of a foreign body in the throat is common with chronic reflux.

Acid reflux trimester by trimester

The progression of reflux symptoms follows a fairly predictable pattern throughout pregnancy. Understanding this timeline helps to anticipate and adapt preventive measures.

First trimester: nausea takes center stage

In the first trimester, acid reflux is relatively rare. The dominant digestive symptoms are more likely pregnancy nausea and vomiting, linked to the rapid increase in HCG hormone. However, some women may already experience heartburn at this stage, due to the early effect of progesterone on the esophageal sphincter. If this is your case, the dietary measures described later in this article apply from the beginning of pregnancy.

Second trimester: the onset of reflux

It is generally in the second trimester that acid reflux makes its appearance. Between 30 and 50% of pregnant women begin to experience heartburn at this stage, mainly after meals and when lying down. The progesterone level continues to rise, the LES relaxes further, and the uterus begins to exert noticeable pressure on the digestive organs. Symptoms are often intermittent and can be well controlled through dietary and postural adjustments.

Third trimester: peak frequency

The third trimester is the period of maximum GER frequency during pregnancy: up to 80% of women suffer from it (Quartarone, 2013). The uterus reaches its maximum size, pressure on the stomach is at its peak, and the esophageal sphincter is maximally relaxed. Symptoms are often daily, worsened by lying down, large meals, and certain foods. It is at this stage that resorting to medication such as Gaviscon often becomes necessary in addition to lifestyle measures.

Anti-reflux diet: the golden rules

Diet plays a central role in managing gastric reflux during pregnancy. Certain foods worsen symptoms by stimulating acid production or relaxing the esophageal sphincter, while others have a protective effect. Here is a practical guide to adapting your diet. For a pregnancy-friendly breakfast, consider incorporating protective foods from the morning.

Foods to avoid

The following foods are known to worsen reflux. Their effect varies from person to person, but it is recommended to reduce or eliminate them if you suffer from heartburn:

• Fatty and fried foods (slow gastric emptying)
• Spicy dishes (irritate the esophageal lining)
• Acidic foods: citrus fruits (orange, lemon, grapefruit), tomatoes and tomato sauces, vinegar
• Chocolate (contains theobromine which relaxes the LES)
• Mint (relaxes the LES despite its refreshing effect)
• Coffee and caffeinated beverages (stimulate acid secretion)
• Carbonated beverages (increase intragastric pressure)
• Raw onions and garlic

Protective foods

Certain foods help neutralize acidity, protect the esophageal lining, or facilitate digestion:

10 practical tips to relieve acid reflux

Beyond diet, several lifestyle habits can considerably reduce the frequency and intensity of heartburn during pregnancy. Here are the 10 most effective measures, supported by medical literature.

1. Split your meals: eat 5 to 6 small meals per day rather than 3 large ones. An overfull stomach increases pressure on the esophageal sphincter and promotes reflux. This approach also helps stabilize blood sugar and reduce the risk of gestational diabetes.
2. Do not lie down for 2 to 3 hours after eating: lying down with a full stomach is the most conducive situation for reflux. Wait at least 2 hours (ideally 3) after dinner before going to bed. Eat a light and early dinner.
3. Elevate the head of the bed by 15 to 20 cm: place blocks under the legs of the headboard or use a wedge pillow. Note: simply stacking pillows is not enough, as it creates an angle at the abdomen that can worsen reflux. The goal is to incline the entire upper body.
4. Avoid tight clothing around the waist: belts, tight pants, and compression tights increase abdominal pressure and promote acid reflux. Choose maternity clothes with stretchy waistbands.
5. Chew sugar-free gum after meals: chewing stimulates saliva production, which is naturally alkaline. This saliva neutralizes acid present in the esophagus and accelerates reflux clearance. A study demonstrated that chewing gum for 30 minutes after a meal significantly reduces acid reflux (Moazzez, 2005).
6. Eat slowly and chew well: eating too fast leads to swallowing air (aerophagia) and less efficient digestion. Take the time to chew each bite thoroughly — aim for at least 20 chews — to ease the stomach's work and reduce gastric volume.
7. Drink between meals rather than during: drinking large amounts of liquid during meals distends the stomach and increases the risk of reflux. Prefer to drink in small sips between meals. Aim for at least 1.5 liters of water per day, spread throughout the day.
8. Sleep on your left side: this position reduces pressure on the esophageal sphincter and promotes gastric emptying thanks to the natural anatomy of the stomach. Sleeping on the left side is also recommended during pregnancy to optimize blood flow to the placenta.
9. Avoid bending forward after eating: bending over to pick something up, tie your shoes, or garden increases abdominal pressure and can trigger immediate reflux. If you need to bend down, bend your knees rather than your waist.
10. Walk for 15 minutes after meals: a gentle walk after meals promotes digestion and gastric emptying, while maintaining an upright position that prevents reflux. However, avoid intense exercise right after eating.

Medication treatments allowed during pregnancy

When lifestyle measures are not enough, medication can be considered. There are three levels of treatment, to be used progressively depending on symptom severity. Never take any medication without the advice of your doctor or pharmacist.

1st line: antacids and alginates (Gaviscon)

Antacids based on sodium alginate (Gaviscon) are the first-line treatment for GER during pregnancy. Their mode of action is mechanical and non-systemic: in contact with stomach acid, the alginate forms a viscous gel that floats on the surface of the stomach contents, creating a physical barrier that prevents reflux. Alginate reduces reflux symptoms by 60% according to studies (Quartarone, 2013).

Gaviscon is authorized throughout pregnancy because it is not absorbed by the body and does not enter the bloodstream. The usual dosage is 10 to 20 ml (1 to 2 tablespoons) after meals and at bedtime, up to 4 times per day. It can be taken as needed when symptoms appear. Magnesium and aluminum-based antacids (Maalox, Rennie) are also permitted for occasional use.

2nd line: H2 blockers (ranitidine)

If antacids fail, your doctor may prescribe an H2 blocker such as ranitidine (formerly Zantac) or famotidine. These medications reduce acid production by blocking H2 histamine receptors on the parietal cells of the stomach. They are more effective than simple antacids because their action lasts longer (6 to 12 hours).

H2 blockers are considered compatible with pregnancy based on available data, but their use should be under medical prescription only. They are generally reserved for moderate to severe reflux cases that do not respond to antacids.

3rd line: proton pump inhibitors (PPIs)

For severe GER cases that are refractory to previous treatments, proton pump inhibitors (PPIs) such as omeprazole (Prilosec) or lansoprazole may be considered. PPIs are the most powerful medications for reducing acid secretion. They directly block the proton pump of the stomach cells, reducing acid production by 90 to 99%.

Their use during pregnancy has long raised questions, but scientific data are now reassuring. A large-scale study published in the New England Journal of Medicine involving over 840,000 births found no increased risk of congenital malformation associated with PPI use in the first trimester (Pasternak and Hviid, 2010). Several subsequent meta-analyses confirmed these results. PPIs nevertheless remain a 3rd-line treatment, to be reserved for cases where the benefits clearly outweigh the theoretical risks.

Natural remedies: what works and what is a myth

Faced with the discomfort of reflux, many pregnant women turn to natural remedies. Some are genuinely effective, while others are more myth than reality. Here is an overview based on available scientific data.

Ginger: helpful but not specifically anti-reflux

The effectiveness of ginger against pregnancy nausea is solidly demonstrated by numerous clinical trials. Its prokinetic properties (it accelerates gastric emptying) may also benefit women suffering from reflux by reducing the time food stays in the stomach. However, there is no specific study demonstrating its effectiveness against GER. It can be consumed as a tea (1 g of fresh grated ginger in hot water) or as crystallized ginger, up to 1 to 1.5 g per day maximum.

Milk: a deceptive relief

Milk is often cited as a remedy for heartburn. It does provide immediate relief by temporarily buffering gastric acidity. However, this effect is short-lived: the proteins and calcium in milk then stimulate acid secretion (acid rebound effect), which can worsen symptoms 30 to 60 minutes after ingestion. Almond milk, which is non-dairy and naturally alkaline, is a better alternative if you are looking for a soothing beverage.

Vichy water and baking soda: with caution

Bicarbonate mineral waters (Vichy Célestins, Saint-Yorre) and baking soda effectively neutralize stomach acid. However, their high sodium content is problematic during pregnancy: excessive sodium intake promotes water retention, edema, and can contribute to high blood pressure. If you wish to consume them, limit yourself to one glass per day and consult your doctor, especially if you are prone to hypertension or edema.

Acupressure and acupuncture: limited evidence

A few preliminary studies suggest that acupuncture may reduce reflux symptoms, but the data remain insufficient to conclude proven effectiveness specifically during pregnancy. Acupressure of the P6 point (Neiguan), used for nausea, has not shown a significant effect on GER. These approaches can be tried as a complement to other measures, but should not replace medical treatment if symptoms are significant.

When to see a doctor?

Pregnancy-related gastroesophageal reflux is in the vast majority of cases benign and manageable. However, certain signs should prompt you to see your doctor, midwife, or go to the emergency room promptly:

• Intense chest pain: any severe chest pain should be evaluated by a healthcare professional to rule out a cardiac cause or esophageal complication.
• Vomiting blood (hematemesis): vomit containing red blood or "coffee ground"-colored material may indicate irritation or ulceration of the esophagus.
• Unintentional weight loss: if reflux prevents you from eating properly and you are losing weight, medical attention is needed to protect your health and your baby's.
• Difficulty swallowing (dysphagia): a sensation of food getting stuck in the esophagus may be a sign of severe inflammation (esophagitis) requiring treatment.
• Persistent symptoms despite treatment: if lifestyle measures and antacids do not relieve your symptoms after 2 weeks, your doctor may adjust treatment or consider additional investigations.
• Associated signs of pre-eclampsia: intense band-like epigastric pain, hypertension, severe headaches, visual disturbances, sudden swelling of the face or hands.

Never hesitate to ask your doctor or midwife. There is no such thing as an unnecessary consultation when it comes to your comfort and the safety of your pregnancy.

Our expert's opinion

"Acid reflux during pregnancy is a very common and almost always benign discomfort. In my practice, I find that the majority of women achieve significant relief with simple measures: splitting meals, avoiding lying down right after eating, elevating the head of the bed, and identifying trigger foods. When these measures are not enough, Gaviscon is a valuable ally, permitted at all stages of pregnancy. For more severe cases, we have medications with a well-established safety profile. The message I want to convey is that you should not endure this burning in silence thinking it's 'normal': it is common, yes, but solutions exist. Talk to your doctor. And keep in mind that these symptoms almost always disappear within days or weeks after delivery."

Dr. Elie Servan-Schreiber, physician and founder of bienmangerenceinte.fr