Genetic association of the xenobiotic biotransformation system with the risk of death of the gestational sac in primigravida women living in an industrial city

Abstract

Introduction. Every second conception in the population ends in failure, in 20% of the cases the cause is a non-developing pregnancy. In the overall structure of early reproductive losses, missed miscarriage accounts for 80%. The development of this pathology is influenced by both endogenous and exogenous factors. Exogenous factors with a teratogenic effect lead to the occurrence of mutations and the formation of an abnormal embryo, which is poorly predicted. The peculiarities of the biotransformation system of xenobiotics of the maternal organism directly affect the severity of the impact of these factors on the embryo. Materials and methods. A survey of eighty six young primigravida women living in Novokuznetsk was conducted. 33 of them were diagnosed with the gestational sac death, 53 women had a standard developed pregnancy. Variants of the GSTM1 and GSTT1 genes of the second phase of the xenobiotic biotransformation system were determined in these groups by polymerase chain reaction. Results. Novokuznetsk, a city with a critically high level of environmental pollution, has recorded a 20–fold increase in the number of missed miscarriages over the past 25 years. A statistically reliable association of deletion polymorphisms of the genes of the second phase of the xenobiotic biotransformation system with the death of the gestational sac - GSTM1 (χ2 – 5.37; OR – 3.18) and GSTT1 (χ2 – 10.85; OR – 16.64) was revealed, while the normal alleles were associated with a successful outcome of pregnancy - GSTM1 (χ2 – 5.37; OR – 0.13) and GSTT1 (χ2 – 10.85; OR – 0.06). Limitations. The study was of a pilot nature, so it is advisable to increase the sample in the future. Conclusion. The dependence between the activity of enzymes of the second phase of the xenobiotic biotransformation system and the increased risk of miscarriage of the first pregnancy in young women living in the conditions of ecological distress was revealed. The results of the study make it possible to predict possible pregnancy complications and elaborate algorithms for full-fledged pregravid preparation.