The level of alkaline phosphatase activity and the content of calcium and phosphorus ions in the blood of pregnant women in different trimesters of pregnancy

Abstract

Calcium-phosphorus exchange is an important part of the metabolism in the human body, which primarily ensures the mineralization processes of hard tissues, including teeth, which is a prerequisite for their resistance to the carious process. The aim of the study was to establish the dynamics of changes in the indicators of calcium-phosphorus metabolism in the blood of pregnant women in different trimesters of pregnancy. An examination and laboratory tests of the blood of 210 pregnant women aged 18 to 36 years were carried out, in which the level of calcium ions, the content of magnesium, phosphate ions and the activity of alkaline phosphatase were determined in the I, II and III trimesters of pregnancy. The degree of probability of the obtained results was statistically assessed. The results of the study indicate an increasing deficit of Ca ion content with increasing gestational age, namely: by 3.33% in the second trimester and by 5.98% in the third trimester compared to the first trimester. The level of phosphate ions was within normal limits and tended to increase in the second trimester of pregnancy by 11.88% with a subsequent decrease in the third trimester by 7.62%. The content of Mg is low and in some places borders on the lower limit of the norm, which indicates the insufficient supply of it to the body of pregnant women. The level of LF enzyme activity in the blood of pregnant women also decreased with each trimester of pregnancy. A strong positive correlation was established between the level of LF activity and the content of Mg in the blood of women throughout pregnancy, namely: I trimester ‒ r=0.75, p<0.05; II trimester ‒ r=0.78, p<0.05; III trimester ‒ r=0.81, p<0.05. Positive correlations of moderate and medium strength were also observed between the level of LF activity and the content of phosphate ions in the blood of pregnant women in the I trimester of pregnancy (r=0.62, p<0.05) and the III trimester ‒ (r=0, 44, p<0.05), which is quite understandable, since the direct result of the enzyme's work is the formation of available phosphate ions, which are subsequently incorporated into the structure of hydroxyapatites. As a result of the conducted research, it was determined that the II trimester of pregnancy is the most vulnerable, which is characterized by changes in all indicators of calcium-phosphorus metabolism and a break in most of the interdependencies between them, which, in turn, indicates the restructuring of metabolic processes in the body of a pregnant woman.

Keywords: pregnancy, calcium-phosphorus exchange, alkaline phosphatase activity, mineralization of hard tooth tissues.