That burning feeling in your chest and throat after eating - or even when you have not eaten - reaches its peak in the third trimester. Acid reflux affects up to 80% of pregnant women by late pregnancy, and two separate biological forces drive it.
Two Reasons It Gets Worse in the Third Trimester
First, progesterone relaxes smooth muscle throughout the body, including the lower oesophageal sphincter - the valve that keeps stomach acid from flowing back up. Second, your growing uterus physically compresses the stomach, increasing pressure and pushing acid toward the relaxed sphincter.
| Factor | First Trimester | Third Trimester |
|---|---|---|
| Progesterone level | Rising | Highest of pregnancy |
| Uterus compression on stomach | Minimal | Significant |
| Stomach capacity | Normal | Reduced by up to 30% |
| Women affected | ~25% | Up to 80% |
Diet Changes That Help
- Eat 5-6 small meals instead of 3 large ones - smaller portions reduce stomach pressure
- Avoid lying down within 2-3 hours of eating
- Elevate the head of your bed by 10-15cm using bed risers or a wedge pillow
- Avoid trigger foods: fatty or fried food, chocolate, citrus, tomato, coffee, carbonated drinks
- Eat slowly and chew thoroughly
- Drink fluids between meals rather than with food
Safe Treatments in Pregnancy
- Antacids containing calcium carbonate (like Gaviscon or Rennie) - safe, effective, provide immediate relief
- Alginate antacids (Gaviscon Advance) - form a gel raft on top of stomach contents, highly effective
- Ranitidine or omeprazole - may be prescribed by your doctor for severe cases
- Avoid antacids containing sodium bicarbonate or aspirin - not recommended in pregnancy
When to see your doctor
If reflux is causing you to vomit blood, causes chest pain radiating to your arm, or is significantly affecting your nutrition or sleep, tell your doctor. Prescription medications are safe and effective in pregnancy.