DETECTION OF Y-CHROMOSOME MARKER IN PLASMA OF PREGNANT WOMEN USING REAL TIME PCR: DIAGNOSTIC ACCURACY DEPENDING ON GESTATION AGE

The evaluation of the clinical significance of the test for the detection of the Y-chromosome marker in the plasma of a pregnant woman at different stages of pregnancy by real-time PCR was carried out. The blood samples of 4616 women at 4 to 32 gestation weeks were studied. Identification of the Y-chromosome marker was carried out based on the amplification of a region of the TSPY gene. The Y-chromosome marker was unambiguously identified in 2131 samples, which accounted for 46.2% of the total number of analyzed samples. In 233 samples (5%), the Y-chromosome marker was detected with reduced reliability, and in 15 samples (0.3%), an unambiguous conclusion about the presence or absence of Y-specific DNA in plasma could not be made during the initial study. The diagnostic accuracy of the Y-chromosome marker determination in the plasma of a pregnant woman at the 4-6th gestation week was 95.5%, and from the 7th week and at later stages of pregnancy it reached 97.3-98.2%. Testing from the 7th gestation week may be recommended for reliable prenatal sex determination of the fetus by real-time PCR analysis of extracellular circulating fetal DNA.