Aim. To study the features of the gas composition and acid-base state in newborns with specific intrauterine infections.Material and methods. The examination was conducted based on the neonatal pathology unit of the SI NMCShifobakhsh.The degree of oxygenation of blood and skin was determined using daily pulse-oximetry. The partial pressure of gases and the study of the acid-base state (CBS) of blood was carried out using Convergys/liquid device.Result and discussion. The results of our study of blood gases and the acid-base indicator of blood in newborns with severe IUI showed noticeable hypoxemia, moderate hypercapnia, and a deficiency of buffer States, which indicate a violation of gas exchange function in the lungs with the development of compensatory respiratory-metabolic acidosis in children of this group. In patients with a very severe course of IUI, as the syndrome of respiratory disorders and the severity of hyperventilation syndrome increased, deeper changes in blood gas parameters and the acid-base state of the blood were noted. It indicates significant damage to the ventilation function of the lungs, diffuse perfusion processes, gas, and acid-base homeostasis.Conclusions. Impairment of the function of organs and systems that developed against the background of a severe or very severe course of IUI, depending on the degree of severity of deviations in blood gas parameters and acid-base balance, shows the need for adequate corrective therapy.

Objective: To evaluate lipid peroxidation (LPO) and antioxidant defense (AOD) system in full-term and preterm neonates with specific intrauterine infections (IUI). Methods: Eighty full-term and preterm newborns with specific IUI were examined; 48 of them (60%) with a severe course of IUI, and 32 (40%) with an extremely severe IUI course. The control group included 30 relatively healthy newborns, including 22 full-term and 8 late premature (born at 34-37 weeks of gestation) neonates. The state of LPO and AOD was assessed by the levels of malondialdehyde (MDA), superoxide dismutase (SOD), ascorbic (AA), and sialic (SA) acids. Enzyme-linked immunosorbent assay (ELISA) of blood serum of newborns with IUI and their mothers was carried out in paired sera, with IgG, IgM, and avidity level (%) of IUI pathogens determined. Results: Analysis of epidemiological data on TORCH infection in the examined neonates revealed diagnostic titers of cytomegalovirus infection (91.3%), herpes (70.4%), toxoplasmosis (50.1%), and chlamydia (43.4%). Comparative analysis of MDA level in the first and control groups showed a statistically significant difference (p 0.05); while its comparison between the 2nd and control group showed even higher level difference (p 0.05). The levels of SOD, AA and SA in the 1st and 2nd groups were highly significantly different from the control group (p 0.001). All these tests showed significant differences between the 1st and the 2nd group (p 0.05), except for the levels of sialic acid (p 0.05). Conclusion: In neonates with specific IUI, statistically significant changes in LPO and AOD parameters were obtained compared with the control group. Enzymatic and non-enzymatic antioxidant parameters can be diagnostically significant for early prediction of infectious processes in the body of a newborn. The revealed changes in the LPO and AOD indicators in the neonates with IUI, dictate the need for timely and adequate antioxidant therapy along with etiotropic treatment. Keywords: Homeostasis, lipid peroxidation, intrauterine infections, antioxidant defense, tricarboxylic acid cycle.