Aim — to study the features of the course and outcomes of the gestational period in cases of clinically and morphologically confirmed diagnosis of placental insufficiency and fetal growth retardation. Material and methods. Prospective study was conducted in 220 C-section patients. Main group consisted of 120 pregnant women whose gestational period was complicated by fetal growth retardation syndrome. Comparison group consisted of 100 pregnant women whose gestational period ended with the birth of full-term babies weighing from 3000.0 g or more. Each group was divided into two subgroups depending on the time of anti-infection therapy (due to infectious and inflammatory complications) up to 16 weeks of the gestational period and after it. Laboratory (microscopic, bacteriological study, polymerase chain reaction method, enzyme-linked immunosorbent assay, hemostasis system data) and diagnostic (ultrasound, dopplerometry) examination methods were certified. The material for the morphological study was the areas of the placenta and placental bed obtained during cesarean section. Results. It was established that the leading role in the genesis of fetal growth retardation belongs to placental insufficiency of infectious genesis, confirmed by morphological studies. The number of observations of infectious and inflammatory changes in the placenta during pregnancy, complicated by the development of fetal growth retardation, was 62.5%. The main pathological reactions in the placental bed of the uterus during pregnancy, complicated by the development of fetal growth retardation, were severe inflammatory infiltration (76.66%), perivascular fibrosis (29.17%) and decidual cell micronecrosis (31.67%), which is morphological confirmation chronic persistent endometritis. In the placental bed in women whose gestational period was complicated by the development of fetal growth retardation, microbial agents were detected in 63.33%: representatives of the Mollicutes class were found in 26.67%; viral infections — in 25.83%; chlamydial infection — in 10.84%. In cases of conducting antimicrobial therapy in patients with inflammatory diseases of the reproductive system at a gestational age of 12—16 weeks, microbial agents in the placental bed were found in 15.79% of women whose gestational period was complicated by the development of fetal growth retardation; with such treatment after 16 weeks — in 84.21%. Conclusion. Placental insufficiency is the underlying condition for the development of complications of the gestational period and outcomes for the fetus. The need for etiotropic, antimicrobial therapy from the beginning of the 13th week of pregnancy is due to the fact that at the beginning of the second trimester of pregnancy (13—16 weeks of gestation) a second wave of cytotrophoblast invasion occurs, which ensures low-resistance blood flow and increased blood supply to the fetus for its growth and development. Diagnostic issues in patients with placental insufficiency and their management algorithms remain very relevant, as they have a direct impact on perinatal and infant mortality and, consequently, the quality of life in the future.