Background: First reported in 1923 due to excessive ingestion of milk and bicarbonate for peptic ulcer disease, milk-alkali syndrome nearly disappeared by the 1980s. More recently, however, this syndrome has become a more common cause of hypercalcemia. This increase is likely due to the increased use of calcium carbonate for the prevention and treatment of osteoporosis. Pregnancy likely places women at risk for milk-alkali syndrome due to increased intestinal absorption of calcium. Recommendations for increased oral calcium intake during pregnancy along with frequent use of calcium carbonate for GI symptoms during late pregnancy increase this risk.
Methods: We performed a retrospective chart review of pregnant women with pre-eclampsia, ages 18-35 years, who were admitted for delivery to the University of Oklahoma Health Sciences Center. Serum calcium levels were reviewed and compared with those of an age- and sex-matched control group consisting of 100 non-pregnant women admitted to the same facility.
Results: Twenty-nine of the 100 pregnant patients (29%) had an albumin-corrected calcium above normal compared to only six patients (6%) in the control group (P = 18.32, p < 0.0001). The highest corrected serum calcium in the pregnant group was 12.3 mg/dl compared to 10.7 mg/dl in the control group.
Summary: Milk-alkali syndrome is not an uncommon cause of hypercalcemia, and pregnancy may predispose women to milk-alkali syndrome as demonstrated by the patient reported. Albumin-corrected calcium is frequently high in women with pre-eclampsia but ionized calcium is not.