Antacids may be used to relieve heartburn and indigestion associated with pregnancy. However, women who are pregnant, thinking of becoming pregnant or breastfeeding should not use antacids without first consulting a physician. There have been no significant human or animal studies regarding the effects of antacids on expectant mothers and their fetuses. However, there have been reports that taking high doses of antacids during pregnancy may cause side effects in babies after birth. In addition, pregnant women who tend to retain water should avoid medications with high levels of sodium (salt), such as antacids.

Antacids containing aluminum, calcium or magnesium may pass into breast milk, but have not been reported to cause problems in nursing infants.