Research Information System
Istanbul Tip Fakultesi Mecmuasi, vol.26, no.sup. 64, 1973 (Scopus)
Results of estimation of total serum alkaline phosphatase and thermostable alkaline phosphatase (placental origin) activity in 164 women during pregnancy and puerperium (and also in healthy males and nonpregnant healthy females) are presented. Total serum alkaline phosphatase activity increases progressively in a curvilinear pattern in normal pregnancies and reaches upper limit of normal value at term. Heat stable alkaline phosphatase activity, which is produced by syncytiotrophoblast in the placenta, is not usually present in the first trimester of pregnancy and then rises in the same fashion as pregnancy progresses. The increase of total serum alkaline phosphatase activity in late pregnancy is entirely due to an increase of enzyme of placental origin. After delivery the enzyme activities of placental or nonplacental origin decline progressively and return to normal nonpregnant limits. In patients with preeclampsia both fractions of alkaline phosphatase show a sharp rise. Variations in total serum alkaline phosphatase and heat stable alkaline phosphatase activity from normal to excessive limits seems to be one of the signs of placental dysfunction and, indirectly, of fetal distress. Abnormal elevation in total and heat stable alkaline phosphatase activities should be taken as an indication of impaired placental function.