The Purpose: to identify additional markers for predicting severe forms of intrauterine infection of the fetus and newborn during prolonged pregnancy with premature rupture of the fetal membranes in a period of 24—33 weeks by studying the dynamics of proteins — α2-macroglobulin, α1-antitrypsin; lactoferrin and albumin in the blood of pregnant women. Material and methods. 26 almost healthy pregnant women (control group) and 34 pregnant women with premature rupture of fetal membranes in the period of 24—33 weeks and prolongation of pregnancy lasting from 7 to 17 days (main group) were examined. In the main group, 12 women gave birth to children without signs of intrauterine infection (1st subgroup), in 11 cases, signs of local intrauterine infection (conjunctivitis, omphalitis, pyoderma) were detected — 2nd subgroup, and 11 patients had newborns with severe intrauterine infection (early neonatal sepsis, intrauterine pneumonia, meningitis) — 3rd subgroup. The content of α2-macroglobulin, α1-antitrypsin was determined by the method of quantitative rocket immunoelectrophoresis; lactoferrin — by enzyme immunoassay; albumin — by biochemical method. Statistical analysis was performed using a certified Instat II program (USA). Results. Concentrations of α2-macroglobulin and α1-antitrypsin remained unchanged throughout the observation period and did not differ from measurements of healthy pregnant women at birth children without signs of intrauterine infection (1st subgroup), were significantly increased at birth of children with local signs of intrauterine infection (2nd subgroup) and sharply reduced at the birth of newborns with severe intrauterine infection (3rd subgroup). Albumin concentration was reduced, and lactoferrin increased, regardless of the condition of the newborn. Conclusion. Concentrations of α2-macroglobulin >3.6±0.2 g/l and α1-antitrypsin >3.75±0.3 g/l in the blood of pregnant women with premature rupture of the fetal membranes or these parameters do not differ from those in healthy pregnant women (α2-macroglobulin — 2.57±0.09 g/l; α1-antitrypsin — 3.0±0.1 g/l) and not changing upon observation, are additional prognostic criteria of the development of intrauterine infection of the fetus and the presence or absence of the possibility of prolongation of pregnancy with the likelihood of having children without intrauterine infection or with mild forms of its manifestations. Low levels of these proteins in the blood from the time of the outflow of water with premature rupture of the membranes (α2-macroglobulin <1.96±0.18 g/l and α1-antitrypsin <2.5±0.22 g/l) indicate severe generalized form of intrauterine infection of the fetus and the need for urgent delivery.