[GENOMIC VARIABILITY DURING PREGNANCY TRIMESTERS].

The article presents data on the genome status of pregnant women in different trimesters of pregnancy, during the normal course of pregnancy. The variability of ribosomal cystone activation as well as the variability of genome stability (frequencies of chromosomal aberrations and fragile sites) in different trimesters of pregnancy have been studied to detect genome-specific functional variability for each trimester.It was found that the level of genome stability determined by the frequency of chromosomal structural disorders and fragile sites in all three trimesters of pregnancy did not differ significantly from similar rates for non-pregnant healthy women. The exception was the frequency of fragile sites in the first trimester of pregnancy, which was statistically significantly higher than the control rate, which may be a specific feature (characteristic) for this trimester of pregnancy.At the same time, specific variability in genomic parameters was identified. In particular, deheterochromatization of pericentromeric heterochromatin and heterochromatinization of the medial region and pretelomeric heterochromatin.Based on data on the activation of Nucleolar organizing regions of acrocentric chromosomes and changes in the frequency of acrocentric chromosome associations, which are statistically significantly higher than the control level, a conclusion is made about increased activity of protein-synthesizing apparatus of the cell in all three trimesters of pregnancy. A statistically significant increase in the associative activity of the 15 acrocentric chromosome in the third trimester of pregnancy has been identified, which may also indicate possible specific modification variability on this chromosome and be characteristic of a given trimester of pregnancy.