3rd Trimester Nutrition: Managing Heartburn & Digestive Discomfort

The third trimester is an exciting time as you near the final stretch of your pregnancy journey. But with a growing baby (and uterus), many women find themselves facing new digestive challenges — namely heartburn and general digestive discomfort.

If you're suddenly avoiding spicy foods or sleeping upright with a bottle of antacids nearby, you're not alone. Around 30–50% of pregnant women experience heartburn during pregnancy, with rates increasing in the third trimester (Ali & Egan, 2007).

Fortunately, there are safe and effective ways to manage these symptoms — and it all starts with nutrition and a few smart lifestyle tweaks.

Why Does Heartburn Happen in Late Pregnancy?

Heartburn (also called acid reflux or gastroesophageal reflux) occurs when stomach acid moves up into the esophagus, causing a burning sensation in the chest or throat.

In pregnancy, it happens for a few reasons:

• Hormones: Elevated progesterone relaxes the smooth muscles of your digestive tract, including the valve that normally keeps stomach acid where it belongs.

• Physical pressure: As your uterus grows, it pushes up against your stomach, making it easier for acid to escape.

• Slower digestion: This is your body’s way of absorbing more nutrients, but it can lead to bloating, fullness, and reflux.

Nutrition Tips to Relieve Heartburn

Making small changes to how and what you eat can make a big difference.

1. Eat smaller, more frequent meals

Large meals can overfill your stomach and increase pressure on the valve between your stomach and esophagus. Try eating 5–6 smaller meals throughout the day rather than 2–3 large ones.

2. Avoid known trigger foods

Everyone's triggers are different, but some common culprits include:

• Spicy foods

• Citrus fruits and juices

• Tomato-based dishes (like pasta sauce or pizza)

• Fatty or fried foods

• Caffeinated drinks (coffee, cola, energy drinks)

• Chocolate

• Peppermint

Keep a food and symptom diary to help you identify your own triggers.

3. Limit fluids during meals

Staying hydrated is essential during pregnancy, but try to drink fluids between meals rather than with them. This reduces stomach volume and pressure after eating.

4. Stay upright after eating

Try to avoid lying down for at least 1–2 hours after a meal. If reflux tends to hit at night, consider:

• Eating dinner earlier

• Elevating the head of your bed slightly

• Using a wedge pillow for extra support

Managing Digestive Discomfort & Bloating

Alongside heartburn, many women experience bloating, gas, and sluggish digestion in the third trimester.

To ease discomfort:

• Increase fibre gradually: Continue aiming for 25–30g of fibre per day to keep bowels moving. Think fruits, vegetables, whole grains, legumes (as tolerated), and seeds.

• Drink plenty of water: Fibre needs fluid to work properly — aim for at least 2–2.5 litres per day.

• Try gentle movement: A 10–15 minute walk after meals can aid digestion and reduce bloating.

• Watch carbonated drinks: Bubbles can contribute to a gassy, full feeling. Swap soft drinks for herbal teas or infused water.

What About Antacids?

Many over-the-counter antacids like calcium carbonate (e.g. Rennie, Quick-Eze) are safe during pregnancy, but always speak to your doctor or pharmacist before starting a new medication.

If heartburn is persistent, your healthcare provider may recommend medications like H2 blockers or PPIs, which reduce stomach acid production more effectively than antacids alone.

Gentle Foods That May Be Easier to Tolerate

When heartburn flares up, bland and soothing foods are often your best bet. Try:

• Oatmeal with banana and almond butter

• Boiled potatoes or sweet potato mash

• Steamed vegetables like zucchini or green beans

• Grilled lean proteins like chicken or fish

• Non-citrus fruits (e.g., melons, pears, apples)

• Plain crackers, rice cakes, or dry toast

Tip: Eat slowly and chew thoroughly to help your digestion start in the mouth.

In Conclusion

Heartburn and digestive discomfort may be common in late pregnancy, but they don’t have to take over your daily life. With a few strategic changes to your eating habits and lifestyle, you can manage your symptoms and feel more comfortable as you head toward the finish line.

Every pregnancy is unique, so if your symptoms are severe or persist despite making changes, don’t hesitate to reach out to your GP, midwife, or dietitian for personalised support.

You’ve made it so far — and your body is doing an incredible job. Keep nourishing yourself and your baby one gentle bite at a time.

References:

• Ali, R. A. R., & Egan, L. J. (2007). Gastroesophageal reflux disease in pregnancy. Best Practice & Research Clinical Gastroenterology, 21(5), 793–806.

• National Health and Medical Research Council (NHMRC). (2014). Nutrient Reference Values for Australia and New Zealand.