Chromosomal disorders in the fetus of pregnant woman from Aktau

Abstract

The article presents the data of cytogenetic study on the fetal karyotype of 310 pregnantwomen from the city Aktau in 2013-2015. Chorionic biopsy and placental biopsy were carried out for248 pregnant women with amniocentesis in 18 cases and cordocentesis in 44 cases. Clinical indicators imposing invasive procedures to pregnant women at risk were maternal age factor, fetal ultrasoundmarkers, serum blood markers determined in pregnant women, the presence of children with multiplecongenital malformations, chromosomal pathologies, etc. Distribution frequencies of fetal chromosomalabnormalities have been determined based on clinical and laboratory studies. The highest frequency ofchromosomal abnormalities of the fetus was indicated in pregnant women with three salient indicators:the factor of the age of the pregnant woman, parameters of biochemical screening, and ultrasound markers. Chromosomal abnormalities of the fetus were detected in 94 (30.3%) pregnant women including 92cases (97.9%) represented by numerical chromosome disorders and 2 cases (2.1%) of structural disorders. Disorders of the autosome system were observed 9.4 times more often comparing to abnormalitiesin the sex chromosome system. Of the numerical chromosome abnormalities, a high specific weight isoccupied by trisomy of the 21-st chromosome which has reached 65.1%. A comparative analysis of thefrequencies of chromosomal abnormalities of the fetus of two port cities has demonstrated a 1.7-foldincrease in the city of Aktau (Kazakhstan) compared with the city of Murmansk (Russia), and the averagefrequencies of fetal karyotype anomalies have made up 19.6% and 11.6%, respectively. Higher level offrequencies for fetal karyotype anomalies in Aktau is possibly associated with unfavorable environmentalconditions in this city caused by the allocation of the oil and gas industry, the repository for tailing toxicand radioactive wastes, and abandoned uranium mines.Key words: karyotype, fetus, prenatal diagnosis, fetal chromosome disorders, ecological state ofurban agglomerations.