What are the recommended antacids for pregnant women experiencing heartburn or indigestion?

Antacids for Pregnancy

Calcium-containing antacids are the preferred first-line antacid choice for pregnant women with heartburn, followed by magnesium-aluminum hydroxide combinations if needed, with sucralfate as an alternative second-line option before escalating to H2-receptor antagonists or proton pump inhibitors. 1

Stepwise Treatment Algorithm

First-Line: Lifestyle and Dietary Modifications

• Begin with small, frequent meals throughout the day rather than three large meals to prevent gastric overdistension 2
• Eliminate spicy, fatty, acidic, and fried foods that trigger reflux 2, 3
• Separate solid and liquid intake to reduce gastric distension 2
• Elevate the head of the bed and avoid lying down immediately after eating 4

Second-Line: Calcium-Based Antacids

• Calcium-containing antacids are the preferred antacid formulation because they provide dual benefit: heartburn relief plus calcium supplementation for maternal and fetal bone health 1, 5
• Calcium carbonate antacids are safe throughout pregnancy and lactation, with no adverse fetal effects 5
• These agents work locally in the stomach without systemic absorption, minimizing fetal exposure 4

Alternative Antacid: Magnesium-Aluminum Combinations

• Magnesium and aluminum hydroxide combinations (with or without simethicone) demonstrate significantly better complete heartburn relief compared to placebo (RR 1.85,95% CI 1.36-2.50) 6
• These combination antacids are considered safe during pregnancy 4
• Avoid magnesium-only antacids near term due to theoretical risk of magnesium accumulation 4

Third-Line: Sucralfate

• Sucralfate 1g orally three times daily is highly effective, showing 2.4 times greater complete heartburn relief compared to lifestyle modifications alone (RR 2.41,95% CI 1.42-4.07) 6, 1
• Works by forming a protective barrier over the esophageal mucosa without systemic absorption 4
• FDA Category B with excellent safety profile during pregnancy 4

Escalation Beyond Antacids

If symptoms persist despite adequate antacid therapy:

H2-Receptor Antagonists (Fourth-Line)

• All H2-receptor antagonists except nizatidine are safe during pregnancy and lactation 4
• FDA Category B agents that can be used when antacids fail 4, 1

Proton Pump Inhibitors (Fifth-Line)

• Reserved for intractable symptoms or complicated reflux disease 4
• All PPIs except omeprazole are FDA Category B 4
• Should only be used after consultation with a physician 1

Critical Safety Considerations

• Avoid sodium bicarbonate-containing antacids due to risk of maternal and fetal metabolic alkalosis and fluid overload 4
• Serious reflux complications during pregnancy are rare, making invasive diagnostic procedures like endoscopy rarely necessary 4
• The physiologic mechanism involves progesterone-induced relaxation of the lower esophageal sphincter, affecting 30-90% of pregnant women 3, 4
• Early treatment prevents progression to more severe symptoms and improves quality of life 2, 7

Lactation Guidance

• Calcium-containing antacids and sucralfate remain safe during breastfeeding due to minimal systemic absorption 4, 5
• H2-receptor antagonists (except nizatidine) are safe during lactation 4
• Most antacids work locally and are not significantly excreted in breast milk 4