Serum constituents in pregnancy including 4 cases with elevated alkaline phosphatase levels.

Serum constituents were analyzed in 350 pregnant women in their third trimester. Results were compared with those from a group of 65 non-pregnant women. Significant differences between the two groups were found for total protein, albumin, calcium, phosphorus, cholesterol, urea nitrogen, uric acid, creatinine, bilirubin, alkaline phosphatase, lactate dehydrogenase and aspartate aminotransferase. Grossly elevated alkaline phosphatase levels were found in 4 subjects from the pregnant group. The source of this elevation was the placenta and placental damage was the probable cause.