Funding: the work was financially supported by the Russian Science Foundation under grant #22-15-00363 "Epigenetic and biochemical aspects of the pathology of pregnancy in violations of the invasive properties of the trophoblast: from early diagnosis to the prevention of maternal and perinatal morbidity", under the Agreement #22-15-00363 of May 13, 2022 for provision of a grant to support fundamental and basic research, made between the Russian Science Foundation, Angelika Vladimirovna Timofeeva (principal researcher/manager for the study) and V. I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology.

Author contribution: Timofeeva AV — study planning, quantitative real-time PCR, Western blotting, manuscript authoring and editing; Fedorov IS — preparation of samples, Western blotting, statistical processing of the data; Tarasova AM — preparation of samples and Western blotting; Gorina KA — clinical profiling of the patients; Suhova YuV — formation of groups of patients for the study, Gusar VA — analysis of the data obtained; Ivanets TYu — screening in the 1st trimester of pregnancy.

Compliance with ethical standards: the study was approved by the Ethics Committee of V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology (Minutes #13 of December 10, 2020), conducted in accordance with the requirements of the Declaration of Helsinki of 1964, Federal Law "On the Fundamentals of Protecting the Health of Citizens in the Russian Federation" #323 -FZ of November 21, 2011 All patients signed a voluntary informed consent form to participate in the study.