Is Alka-Seltzer safe during pregnancy?

What does the evidence say about Alka-Seltzer during pregnancy?

1. Alka-Seltzer Original lists three actives per tablet: anhydrous citric acid 1,000 mg as an antacid, aspirin 325 mg as an NSAID analgesic, and sodium bicarbonate 1,916 mg as an antacid. Each tablet contains 567 mg of sodium. 1
2. The Alka-Seltzer Original label states it is especially important not to use aspirin during the last 3 months of pregnancy unless definitely directed to do so by a doctor, because it may cause problems in the unborn child or complications during delivery. 1
3. Alka-Seltzer Heartburn contains only anhydrous citric acid 1,000 mg and sodium bicarbonate 1,940 mg, with no aspirin, and carries 575 mg of sodium per tablet. The cap is 8 tablets in 24 hours for adults and children 12 and over, dropping to 4 tablets for adults 60 and over. 2
4. The FDA recommends not using NSAIDs after 20 weeks of pregnancy unless a healthcare provider specifically recommends it, and regular strength aspirin later in pregnancy might cause premature closure of the ductus arteriosus as well as bleeding during pregnancy, after delivery, or in the newborn's brain. 3
5. Sodium bicarbonate is approved to relieve heartburn, acid indigestion and upset stomach, and one 650 mg tablet carries 7.7 mEq of sodium and bicarbonate ions. Clinicians are advised to weigh risks and benefits in pregnancy because comprehensive human data are unavailable. 4

Is Alka-Seltzer safe in each trimester?

• First trimester. The first-trimester question is really an aspirin question. If the tablet in your hand lists aspirin among the actives, it is an NSAID dose, not an antacid dose, and it belongs in a provider conversation rather than a shelf decision you make alone. The aspirin-free heartburn version sidesteps that entirely.
• Second trimester. From 20 weeks, the FDA recommends not using NSAIDs unless a healthcare provider specifically recommends it, because of effects on the fetal kidneys and the amount of amniotic fluid. That timing lands squarely in the second trimester and applies to the aspirin-containing versions of this product line.
• Third trimester. Late pregnancy is when both the aspirin and the sodium matter most. The Alka-Seltzer Original label states it is especially important not to use aspirin during the last 3 months of pregnancy unless a doctor directs it, and swelling makes a 567 mg sodium load per tablet worth noticing.

What is actually in each Alka-Seltzer tablet