Introduction. Premature birth can occur at any age; however, it is important to note that the risk of preterm birth can vary based on several factors, including the mother’s medical history, general health, and lifestyle. There is thought to be a relationship between maternal age and the risk of preterm birth, although the exact nature of this relationship may vary. At the same time, it is considered for ages over 35, an increased risk factor for the evolution of pregnancies with complications. Pregnant women over 35 face a higher risk of premature birth. This increased risk may be associated with age-related factors such as underlying health conditions, higher rates of multiple pregnancies (due to fertility treatments), and potential placental dysfunction. Material and methods. In the given study, the biomarkers IL-6, IL-8, IL-10, IL-12, SDF-1α and VEGF in amniotic fluid (AF) and maternal blood were investigated, considering the above as predictive of premature birth outcome. At the same time, the oxidative stress status of maternal blood and amniotic fluid collected in the second trimester of pregnancy was identified. Results. In the research, we obtained statistically significant increases in the biomarkers AAT-isopropyl, G-GTP, HPL-isopropyl from the amniotic fluid taken from pregnant women over 35 years of age in the second trimester of pregnancy in those pregnant women who had a preterm birth. In the serum of pregnant women with premature birth, an increase in the concentration of carnosine-histidine peptides, G-GTP, GR and SH (thiol) groups was identified, and the decrease in the values of SDF 1α, HPL – hexane and IL-12 were statistically significant in the serum pregnant women compared to that of the amniotic fluid. Identifying the values of biochemical mediators during pregnancy can be a method of predictive diagnosis Conclusions. Our study shows the relationship between some concentrations of oxidative stress biomarkers (AAT-isopropyl, HPL-isopropyl and G-GTP, IL-12) in amniotic fluid, and values of (Carnosine Histidine Peptide, GR and SH and SDF-1α) in the serum of pregnant women, in the second trimester of pregnancy.