Objective. To the study the prognostic value of clinical and anamnestic factors and indicator of endothelial function for the implementation of early reproductive losses. Material and methods. The study involved 150 pregnant women: 38 women with early reproductive losses in this pregnancy (the main group) and 112 women with delivery of live full-term infant (the comparison group). Results. The first trimester Loss is associated with impaired endothelial function: increased blood glucose level, impared balance of vasoconstrictors and vasodilators, increased level of homocysteine and decreased activity von Willebrand factor. Conclusion. The most significant indicators involved in the pathogenesis of early pregnancy losses not associated with a chromosomal abnormality and congenital malformations of fetus, are the plasma glucose level and markers of endothelial dysfunction. The flycemia evaluation in the first trimester can be used not only as a screening test, but also as a predictor of a high risk of early pregnancy loss associated with impaired endothelial function.