A case of isolated peripartum elevation of alkaline phosphatase in pregnancy complicated by gestational diabetes.

Several isoenzymes of alkaline phosphatase are present in pregnancy, the most common are of liver, bone, and placental origin. We report a case of pregnancy complicated by hypertension and gestational diabetes, in which an extremely high elevation in bone isoenzyme was noted during labor. The enzyme level returned to normal by six weeks postpartum. Elevations in total serum alkaline phosphatase during pregnancy or labor cannot be assumed to arise from the placenta, and should be further investigated to determine the specific isoenzyme.