Background. The prevalence and severity of complications of gestational diabetes (GD) remain a significant problem worldwide. The desire to improve pregnancy outcomes, as well as an understanding of carbohydrate metabolism disorders, has led to studies demonstrating the presence of various pathogenetic subtypes of GD. Thus, studies have already demonstrated that pregnant women with GD and severe insulin resistance (IR) not only have more unfavorable prognoses, but also differ phenotypically and biochemically. Identification of biochemical markers of different GD subtypes has the potential to improve early diagnosis of a specific subtype and personalize treatment depending on the predominant pathogenetic factor.
Objective. Determineation of the biochemical markers for the diagnosis of various GD subtypes in pregnant women.
Methods. A single-center, observational, prospective, uncontrolled study included 130 pregnant women undergoing outpatient examination between March 2020 and March 2022. Based on the results of an oral glucose tolerance test with 75 g of glucose, 88 patients were diagnosed with GD: 43 were diagnosed with GD subtype with impaired β function-cells (GD I), 45 had the GD subtype with predominant IR (GD II), 42 patients formed the control group. Additionally, insulin was determined at three points to calculate the Matsuda index, fasting levels of total cholesterol (TC), triglycerides (TG), high and low density lipoproteins (LDL), apolipoprotein A (Apo-A), apolipoprotein B (Apo-B), adiponectin, leptin and omentin were examined
Results. Pregnant women from the GD II group had statistically significantly higher TG values (P=0.01 when compared with the GD I group, P<0.001 when compared with the control group), the total cholesterol and LDL levels were higher compared to those in patients from other groups, but these changes were not statistically significant. The (Apo-A) level was significantly higher in patients with GD (P<0.001 when comparing both GD groups with the control group) and did not differ when comparing different GD subtypes, in contrast to the Apo-B level, which was significantly higher in pregnant women from the group GD II compared with that in pregnant women from the other two groups (in both cases P=0.02). When studying adiponectin, leptin and omentin, statistically significant differences were detected only in the level of adiponectin (the lowest level in pregnant women from the GD II group compared with participants in other groups, P<0.001 - when compared with the GD I group; P=0.004 – with the control group ). It was not possible to detect significant differences in omentin and leptin levels within the study.
Conclusion. High levels of Apo-B, TG, and low levels of adiponectin can be used as potential biomarkers in scientific and clinical practice to verify the pathogenetic subtype of GD with severe IR, most unfavorable factor regarding the prognosis according to previous studies.

Keywords: pathogenetic subtypes, omentin, gestational diabetes, insulin resistance, adiponectin, leptin, cholesterol