Objective - to estimate the prognostic value of clinical, anamnestic, microbiological, and biochemical factors in the genesis of early reproductive losses unassociated with fetal chromosomal abnormalities. Subjects and methods. The investigators analyzed the results of clinical, anamnestic, and laboratory examinations in 150 women followed up from the early stages of pregnancy, as well as gestational outcomes. A study group included 38 women whose pregnancy ended in early reproductive losses; a comparison group consisted of 112 women whose pregnancy resulted in full-term live babies. The laboratory, clinical, and anamnestic factors were assessed in the first trimester of progressive pregnancy. Results. Microbiological, molecular biological, immunological, biochemical, morphological, and cytogenetic studies were used. The investigation performed could establish the most important clinical, anamnestic, and laboratory risk factors for reproductive losses unassociated with fetal chromosomal abnormalities, whose identification promotes the timely detection of women at risk of early miscarriage. These included late reproductive age (older than 35 years), misbirth as a reproductive onset, opportunistic microorganisms (Ureaplasma urealyticum) in the diagnostically significant titer; a seronegative status against rubella virus; and carbohydrate metabolic disturbance. Conclusion. A fasting venous plasma glucose level may be considered to be one of the effective indicators of impaired maternal-fetal interactions in the early stages of pregnancy since it not only suggests the presence of gestational diabetes mellitus, but also affects the development and progression of endothelial dysfunction that mediates poor pregnancy outcomes in the majority of cases.