Aim. To dev elop the pr ognostic model to calculate the probability of severe preeclampsia in healthy young reproductive age woman. Materials and methods. This study included two groups of healthy women aged 18-35 years with spontaneous singleton pregnane)': 100 patients with severe preeclampsia (patient group), and 100 women with non-complicated pregnancy (control group). All women had not a risk factors of preeclampsia such as history of hy pertension, auto-immune, metabolic, renal, or cardiac diseases, and family or individual history preeclampsia or thromboembolism before this pregnancy. Their body-mass index in the 1-st trimester of gestation was