Scientists from the Research Institute of Medical Genetics of the Tomsk National Research Medical Center found that the contribution of chromosomal abnormalities to spontaneous miscarriage is greater than previously thought. Therefore, almost 68% of embryos have chromosomal mutations incompatible with development, not 50% as commonly believed. The Ministry of Education and Science of the Russian Federation told socialbites.ca about this.
Today, 23 million pregnancies are lost every year worldwide. Approximately 10-15% of pregnant women face this problem. The main reason for this is chromosomal abnormalities incompatible with the development of embryo cells.
“Scientists used the latest technologies: genome-wide analysis on microarrays with analysis of parental chromosome variants and, for the first time in world practice, they carried out a comparative study on tissues of different germ layers (layers). Thus, in 35% of embryos with a normal set of chromosomes, it was possible to detect mutations that were previously impossible to detect,” Director of the Tomsk National Research Medical Center, Academician of the Russian Academy of Sciences Vadim Stepanov told socialbites.ca.
The study improves the accuracy of diagnosing chromosomal abnormalities, explains the causes of most miscarriages, and reduces the burden of searching for other possible causes of pregnancy loss related to maternal health.
“We are faced with the phenomenon of chromosomal mosaicism, when there is a mutation in one tissue and no mutation in the other. What does this mean? To obtain a reliable result, at least two tissue types need to be analyzed, and to date this has not been done,” said deputy director of scientific work of the Tomsk National Research Medical Center, Igor Lebedev Research Medical Center, head of the genetics laboratory of the Tomsk National Research Institute of Medical Genetics. Professor of the Russian Academy of Sciences told socialbites.ca.
The results suggest that the preimplantation genetic testing protocol should be modified if a geneticist analyzes the embryo during the in vitro fertilization (IVF) process.
Often during IVF, some of the cells of the trophectoderm, which is one of the embryonic membranes of the fetus and forms the future placenta, and not the embryo itself, are taken for analysis.
In case of a normal set of chromosomes, questions about the transfer do not arise. But in recent years, the statistics of successful transfers of so-called “mosaic embryos”, which, according to the results of trophectoderm analysis, have cells with both normal and abnormal sets of chromosomes, are actively increasing. This increases the risk of miscarriage.
“This risk arises from the fact that the chromosomal composition of the inner cell mass in which the embryo will develop is not available for preimplantation genetic testing. The results of our study show for the first time that spontaneous miscarriage is accompanied by the accumulation of mosaic chromosome abnormalities, especially in cells originating from the inner cell mass,” emphasized Lebedev.
Previously gynecologist Ilyina in the name Six factors that cause premature birth.
Source: Gazeta
Barbara Dickson is a seasoned writer for “Social Bites”. She keeps readers informed on the latest news and trends, providing in-depth coverage and analysis on a variety of topics.