COMPARATIVE ANALYSIS OF THE ELEMENTAL STRUCTURE OF THE PLACENTA AT TERM AND PRETERM PREGNANCY
Objective. To conduct a comparative analysis of the content of chemical elements in placenta in the case of term and preterm pregnancies. Methods. The content of some chemical elements was established: carbon (C), nitrogen (N), oxygen (O<sub>2</sub>), calcium (Ca), chlorine (Cl), potassium (K), sodium (Na), phosphorus (P) in 280 biopsies. Tissue extraction was carried out at five points of placenta: chorionic and basal plates in the parenchyma of the placenta, the navel-string part of the placenta and membranes of every tested woman. All mothers’ placenta material was divided into two groups according to the gestational age. The main group consisted of women (n=42) with 24-35 weeks gestational age. The women (n=14) with 39-40 weeks of the gestational age entered the control group. The study of pecularities of the accumulation of the content of certain chemical elements in the placenta biopsy was carried out with the help of a scanning electron microscope SEM EVOLS10 (Zeiss, Germany) with EDS Oxford-X-Max-50 (Oxford, UK) in a low vacuum mode with an accelerating voltage of 20 kV and a current on the sample of 470 pA. The test of Mann-Whitney and the Kruskal-Wallis criterion were used for statistic analysis. Results. It was stated that the structure of general content of some chemical elements: carbon, nitrogen, calcium, chlorine, potassium, sodium, phosphorus in the placenta at term and preterm pregnancies is the same. It was noted that general content of oxygen in the main group was considerably smaller than that in the control group (p=0,006). The content of the studied chemical elements was different in the groups of study and depended on the point of material intake. At preterm pregnancy the content of chemical elements in the navel-string part of placenta statistically differed from other points of material intake. Conclusion. The stated regularities in accumulation of some chemical elements in the placenta at a preterm pregnancy can serve as an orientation for the comparison with the mothers’ placenta of preterm babies with retinopathy of prematurity.