BioMed Central (BMC) Gastroenterology Journal:

Gastroesophageal reflux disease (GERD) is one the most common medical complaints in pregnant women. Its prevalence has been reported to reach as high as 80% in certain populations. The prevalence of GERD is also increased as pregnancy progresses from the first to third trimester. Some women continue to experience GERD symptoms after delivery. Effective management of GERD symptoms is important to improve productivity and quality of life.

Symptoms in pregnancy:

Regurgitation, acid taste in mouth and heartburn are among the most common GERD symptoms, with heartburn and regurgitation causing the most significant negative impact. Heartburn and acid reflux have also been shown to be associated with severity of nausea and vomiting during pregnancy

Management of heartburn in pregnant and breastfeeding women:

Management of heartburn in pregnant and breastfeeding women involves lifestyle modifications, dietary modifications, non-pharmaceutical remedies and pharmaceutical drugs.

For patients who require a more intense intervention, various types of pharmaceutical drugs such as alginates, antacids, sucralfate, H₂ receptor antagonists (H₂RA) or proton pump inhibitors (PPI) are available. However, the suitability of each treatment for use during pregnancy and lactation must be taken into consideration.

This review aims to assess the efficacy and safety of alginate-antacids for relieving heartburn during pregnancy and lactation, based on recent evidence.

The optimum management of GERD in pregnant and breastfeeding women requires consideration of the drugs' safety as well as efficacy, since the medications may affect the foetus/infant

Antacids, alginates, and sucralfate are considered safe and effective as the first-line medical therapy relieving the symptoms of heartburn in pregnancy.

Alginates in treating heartburn in pregnancy:

Alginate formulations for GERD treatment are frequently combined with antacids such as sodium bicarbonate. The sodium bicarbonate component in the alginate formulation releases carbon dioxide within the alginate gel; this causes the gel to float to the top of the stomach contents to form a raft structure.

The alginate-antacid raft forms a non-systemic barrier over the postprandial acid pocket to reduce postprandial acid reflux. In an alginate/antacid combination, the rapid antacid action works concurrently with the long-lasting alginate reflux suppression.

Diagram of alginate raft structure formation following ingestion of an alginate-containing formulation. Alginates react with the stomach acid to form a gel-like substance with neutral pH (A). Sodium bicarbonate contained in the formulation releases carbon dioxide gas, which becomes trapped in the gel. The trapped carbon dioxide gas allows the gel to float to the surface of the stomach content (B), effectively forming a raft structure (C) which acts as a barrier over the gastric acid pocket, and blocks against upward reflux.

Maternal alginate absorption is limited and alginates are not significantly metabolized. Thus, alginates are considered acceptable for use during lactation. Its mode of action and long-term experience with its use indicate that they are safe to use in high-risk pregnancies and breastfeeding populations.