Chromosomal disorders in the fetus of pregnant woman from Aktau

Abstract

Abstract. The article presents the data of cytogenetic study on the fetal karyotype of 310 pregnant
women from the city Aktau in 2013-2015. Chorionic biopsy and placental biopsy were carried out for
248 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 ultrasound
markers, serum blood markers determined in pregnant women, the presence of children with multiple
congenital malformations, chromosomal pathologies, etc. Distribution frequencies of fetal chromosomal
abnormalities have been determined based on clinical and laboratory studies. The highest frequency of
chromosomal 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 92
cases (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 abnormalities
in the sex chromosome system. Of the numerical chromosome abnormalities, a high specific weight is
occupied by trisomy of the 21-st chromosome which has reached 65.1%. A comparative analysis of the
frequencies of chromosomal abnormalities of the fetus of two port cities has demonstrated a 1.7-fold
increase in the city of Aktau (Kazakhstan) compared with the city of Murmansk (Russia), and the average
frequencies of fetal karyotype anomalies have made up 19.6% and 11.6%, respectively. Higher level of
frequencies for fetal karyotype anomalies in Aktau is possibly associated with unfavorable environmental
conditions in this city caused by the allocation of the oil and gas industry, the repository for tailing toxic
and radioactive wastes, and abandoned uranium mines.
Key words: karyotype, fetus, prenatal diagnosis, fetal chromosome disorders, ecological state of
urban agglomerations.