Causes of heartburn in the third trimester

Pregnancy hormones can relax the valve between the stomach and oesophagus, allowing acid or food to move upwards. As the baby and uterus grow, pressure on the stomach can make this movement more likely, particularly after meals or when lying down.

Acid Reflux is a common explanation, but Gastritis, a Hiatus Hernia, or a Peptic Ulcer can also cause upper abdominal burning. Obesity may increase pressure on the stomach. Heartburn can feel uncomfortable without harming the baby, but severe or unusual symptoms should not be assumed to be reflux.

Try smaller meals, remain upright after eating, and avoid foods or drinks that clearly trigger symptoms. Choose comfortable clothing and ask your maternity clinician or pharmacist before taking an antacid or other Acid Reflux Medication, because pregnancy affects which products are suitable.

Record when symptoms occur, what you ate, your position, and any associated nausea or pain. Mention frequent symptoms at antenatal appointments, especially if they disturb sleep or make eating difficult.

Seek urgent advice for severe upper abdominal pain, pain under the ribs, severe headache, vision changes, sudden swelling, repeated vomiting, or feeling very unwell. Emergency help is needed for chest pressure, breathlessness, fainting, vomiting blood, or black stools.

Ask which medicines are suitable in pregnancy, whether your symptoms need testing, how to distinguish reflux from other causes of upper abdominal pain, and which warning signs should prompt immediate contact.