The aim of the study – to optimize the prediction of primary placental dysfunctiondevelopment by determining the risk factors for its development in women with a threatof miscarriage in the early stages of pregnancy.Materials and methods. A prospective analysis of the somatic, reproductive and obstetricanamnesis of 40 pregnant women with threatened abortion in the 1st trimester ofpregnancy and clinical manifestations of placental dysfunction (PD) was carried out –the main group, 60 pregnant women with threatened abortion without PD (comparisongroup). The control group consisted of 50 women with the physiological course of the firsttrimester of pregnancy. Results. Among those with symptoms of threat of termination of pregnancy in the earlystages of pregnancy and PD, the number of women of borderline reproductive age (≤18years and ≥40 years), with obesity (BMI > 30) and a combination of several co-morbidextragenital pathologies was significantly higher than in the comparison group and inthe control group. In the anamnesis of pregnant women of the main group, gynecologicaldiseases, early pregnancy losses (spontaneous miscarriages and non-developingpregnancies) were significantly more often detected. In the first trimester of pregnancyvaginal bleeding, chorionic detachment, retrochorionic hematoma, and low chorionicposition were diagnosed significantly more often in women of the main group. In 7.5 % ofcases, in the first trimester of pregnancy, pregnant women with a threat of abortion andPD had an acute respiratory viral infection.The relationship between the development of primary PD and the frequency of gestationalcomplications associated with the placenta (PE (20.0 %), Abruptio placentae (17.5 %),fetal growth retardation syndrome (10.0 %) and fetal distress (27.5 %)) was established.Every third pregnancy ended in premature birth (32.5 %). The percentage of deliveries byCS in the main group was 62.5 %. Complications of pregnancy and childbirth, associatedwith impaired placental function, led to a high frequency of births of babies in a state ofmoderate and severe asphyxia (15.0 % and 5.0 %, respectively) and stillbirths.Conclusions. The conducted studies confirmed that the development of placentaldysfunction from the early stages of pregnancy in women with a threat of abortion isthe cause of the complicated course of pregnancy and childbirth, which lead to adverseperinatal consequences. Risk factors for the development of placental dysfunctionin pregnant women with threatened abortion are the borderline reproductive age ofthe mother, obesity, a combination of several co-morbid extragenital pathologies,gynecological diseases and early reproductive losses in the anamnesis. Also, the riskfactors for impaired placental formation are detachment of the chorion, retrochorialhematoma, and acute respiratory viral infections in the early stages of pregnancy.