The dissertation is devoted to the improvement of methods for early diagnosis of kidney damage and the prediction of preeclampsia at the preclinical stage of manifestation in pregnant women. To achieve this goal, the work was carried out in four stages. At the 1st stage of the study, in 91 pregnant women in the first trimester, anamnestic factors influencing the development of preeclampsia were collected. The main group (I1) included 56 pregnant women who had one high or several moderate risk factors for preeclampsia, and 35 healthy pregnant women who made up the control group (I2). As a result of the age composition of pregnant women and anthropometric data, it was found that the age composition of women in the main group (I1) is (31.88±0.86) years and higher in comparison with the same indicator in the control group (I2) (28.37±0.74) years. The mean pre-pregnancy weight of women in the intervention group was (73.69±2.48) kg with a body mass index (BMI) of (26.7±0.86) kg/m2, while the weight reference was (61.85±1.48) kg/m2 and BMI (22.5±0.59) kg/m2, (p<0.001). During the analysis of anamnesis and extragenital pathology, the study included 36 women with 1 pregnancy, of which 23 were in the main and 13 in the control groups. The main group consisted of pregnant women with the following factors: multiple twin pregnancies, with a history of kidney disease, the presence of chronic hypertension, antiphospholipid syndrome, in vitro fertilization, PE during previous pregnancy, PE in the mother. At the 2nd stage, four subgroups were formed: II1 - 47 pregnant women with placenta location along the anterior wall of the uterus and II2 - 44 pregnant women with placenta location along the posterior wall of the uterus, II3 - 27 pregnant women with cystatin C ˃1.0 mg/l and II4 - 64 pregnant women with cystatin C ˂1.0 mg/l. who made up group III1 and 65 women did not develop, which is attributed to group III2. The corrected obstetric factors that led to PE can be distinguished in the direction of decreasing importance as follows: 1 - During previous pregnancy, PE VS 6; 2 - Multiple pregnancy VS 2.56; 3 – 1st pregnancy OR 1.83; 4- IVF VS 1.72; 5- Maternal PE 1.57; 6- The interval of ≥10 years between pregnancies is 0.77. Group III1 included 19 pregnant women with the location of the placenta along the anterior wall of the uterus and 7 pregnant women with a posterior location. The odds ratio for the risk of developing PE when the placenta is located on the anterior uterine wall is 3.59 with a sensitivity of 56.92% and a specificity of 73.08%, an accuracy of 61.54% (p = 0.019). Thus, in group III1, the values are (1.46±0.06) mg/l, i.e. at the preclinical stage of PE implementation they exceeded the reference norm of 1.0 mg/l; in group III2, the values within the normal range are (0.84±0.01) mg/l. GFR for cystatin C in group III1 is a significant impairment of the renal filtration system - (52.46±2.08) ml/min/1.73 m², while in group III2 the indicator is (97.6±1.64) ml/min/1.73 m². In the ROK analysis in the PE group, for cystatin C values of 1.02–1.12, the area under the curve is 1, which characterizes the model as excellent, with a sensitivity of 92.86%, specificity of 98.48% and accuracy of 96.81%. When analyzing the ratio of cystatin C levels greater than 1.0 mg/l and the development of PE, a sensitivity of 98.46%, specificity of 100% and an accuracy of 98.9%, p <0.001 were noted. The mean serum creatinine level in pregnant women who subsequently developed preeclampsia (III1) was (76.68±1.81) μmol/L with creatinine GFR (90.23±2.83) ml/min/1.73 m² and are within the reference norm for healthy pregnant women. At the 4th stage, the IV1 group included pregnant women with the classic form of renal failure, the IV2 group included the group of women with hepatic failure, and the IV3 group included women with uteroplacental dysfunction. The most significant factors that led to PE by clinical forms in the leading renal failure syndrome were: location of the placenta along the anterior wall of the uterus (75%), first pregnancy (46.15%), age of the pregnant woman 35 years or more (37.5%), history of chronic kidney disease (31.25%). In the leading syndrome of PE with hepatic insufficiency: PE in previous births (100%), first pregnancy (80%), location of the placenta along the anterior wall of the uterus (40%) and PE in the mother (40%). In leading PE syndrome with uteroplacental dysfunction: location of the placenta along the anterior wall of the uterus (100%), first pregnancy (60%) and BMI ˃30 kg/m2 (60%). Regardless of the distribution by clinical forms of PE, the values of the biomarker of acute kidney injury cystatin C at the preclinical stage of PE implementation exceeded the reference values (1.0 mg/l) of healthy women. The obtained results of the study make it possible to detect damage to renal function at the preclinical stage of PE development, the values of the marker of renal function cystatin C do not depend on the man
