Molecular cytogenetic study of the fetal genome in idiopathic recurrent pregnancy loss.

Objective: Despite numerous studies on the causes of recurrent pregnancy loss (RPL), nearly half of cases remain unidentified, which determines the research relevance. This study aims to investigate microchromosomal variations in the fetal genome associated with the development of idiopathic RPL.

Methods: The research was supported by the Centre for Molecular Medicine and the Research Institute of Obstetrics, Gynecology and Perinatology and conducted over a period of 2 years. The study employed the Prepito automatic analyzer from PerkinElmer and the ChemagicPrepito nucleic acid extraction system, to isolate 100 DNA samples from conception products of women with idiopathic RPL, and, subsequently, to analyze for the presence of full-genome chromosomal abnormalities by array comparative genomic hybridisation (aCGH) using CGX-HD microarrays (8x60K), Format 1: CGX (80x60K), a ScanRI microarray scanner (PerkinElmer, Finland), and Genoglyphix, Cytogenomix software.

Results: The study determined that 83% of the materials studied had a normal molecular karyotype, while unbalanced chromosomal abnormalities were detected in 17% of cases, of which 35.3% of abortions had aneuploidies and 64.7% had various structural abnormalities. Among the aneuploidies, 66.7% were trisomies and 33.3% were monosomies. In the group of structural disorders, 81.8% were microdeletions, while microduplications accounted for 18.2%. The data obtained on the frequency and structure of chromosomal abnormalities detected in abortions in the sample surveyed showed that idiopathic RPL is not caused by chromosomal abnormalities of embryos and, unlike all other forms of RPL, has a different cause not related to chromosomal abnormalities.

Conclusion: This study conducted molecular cytogenetic analysis of the fetal genome related to RPL. Its findings can help optimize the process of counseling patients with idiopathic RPL.