Objective. To develop a method for determining the risk of reproductive loss in the 1st trimester of pregnancy.Materials and methods. Blood serum, whole blood, medical records of an inpatient (form No. 003/-07), and exchange cards (form No. 113/-07) of 94 pregnant women. Interleukin-6 concentration was assessed in the examined patients by immune-enzyme analysis. The level of leukocytes and monocytes was determined in whole blood by general clinical routine methods on a hematology analyzer. Statistica 10.0 software package and “R” programming language, version 4.1, were used for statistical analysis.Results. The developed logistic regression equation (sensitivity, 87.5%; specificity, 83.33%; classification accuracy, 86.17%) by determining the linear predictor Z makes it possible to assign a pregnant woman to the high risk group for the development of reproductive loss in the 1st trimester (Z > -0.4519).Conclusion. The proposed new method for determining a high risk of developing reproductive loss in the 1st trimester of pregnancy makes it possible to carry out appropriate therapeutic measures to help preserve women’s reproductive health, improve fertility, and increase the birth rate.