Purpose - to conduct an analysis of the combined prenatal screening of the trimester I of pregnancy in women who had complications from the group of great obstetric syndromes. Materials and methods. A retrospective statistical analysis of the combined prenatal screening of the trimester I was carried out. Of the 239 pregnant women (Group I - main) who had complications from the group of great obstetric syndromes, according to the data of the pregnancy monitoring exchange cards, combined prenatal screening of the trimester I was carried out in 65.3% of pregnant women, which amounted to 156 pregnant women who were divided into three subgroups: Ia (n=74) pregnant women with severe preeclampsia, Ib (n=40) pregnant women with placental insufficiency, clinically verified fetal growth retardation; Ic (n=42) of pregnant women with spontaneous premature birth in the gestation period of 22-36 weeks. The control group (CG) was 56 practically healthy pregnant women with a healthy reproductive history and an uncomplicated course of this pregnancy. Statistical processing of the research results was carried out using standard Microsoft Excel 5.0 and Statistica 6.0 programs. Results. In the Group I, the average term of trimester I screening was 12 weeks 3±4 days, in the CG - 12 weeks 1±3 days, the difference in the gestational term of the trimester I combined screening was statistically insignificant. The lowest level of PAPP-A was determined in subgroups Ia and subgroup Ic. In the Group I, the level of PAPP-A was on average 2.16 (1.35-3.24) IU/l and 0.836 (0.571-1.14) MoM, and in CG - 2.62 (1.82-4, 12) MO/l and 1.16 (0.786-1.7) MoM. According to the relative number of patients with a level of PAPP-A <0.5 MoM, no significant differences were found between the Group I and CG, but in subgroup Ib the percent of such patients was the highest, which is significantly more than in CG. More significant differences were found at the level of PAPP-A <0.3 MoM: in Group I there were 11 (7.05%) patients with a level of PAPP-A <0.3 MoM, in CG - 1 (1.78%). The number of patients with a level of PAPP-A >1.5 MoM, on the contrary, turned out to be the largest in CG - 15 (26.8%) compared to 23 (14.7%) in the Group I and with subgroup Ia - 9 (12.2%). The level of β-hCG in the studied groups was not statistically significant. There was no statistically significant difference in the thickness of the nuchal translucency, but in the Group I this indicator was slightly higher. The largest nuchal translucency value was in subgroup 1b. There were no statistically significant differences in the frequency of the absence of imaging of the nasal bone during ultrasound screening. According to the frequency of detection of reverse blood flow in the ductus venosus, it was not possible to detect statistically significant differences. This sign occurred only in 3 (1.92%) patients of the Group 1 (1 patient in each subgroup) and in 1 (1.78%) patient of CG. Conclusions. In patients who later developed pregnancy complications belonging to the group of great obstetric syndromes, in the trimester I, a number of prenatal screening indicators differ from those in patients with a physiological course of pregnancy. When conducting a standard set of prenatal diagnostics, the most significant differences were found in the level of PAPP-A (MoM). The results obtained during the analysis of PAPP-A are promising from the point of view of using this parameter as an element of the prognostic model of great obstetric syndromes for the successful course of pregnancy and the birth of a child with a normal body weight. The research was carried out in accordance with the principles of the Declaration of Helsinki. The research protocol was approved by the Local Ethics Committee of the institution mentioned in the work. Women’s informed consent was obtained for the study. No conflict of interests was declared by the author.