[THE ROLE OF SEXUAL DYMORPHISM AND THE STATE OF THE ARTERIAL DUCT IN THE FORMATION OF OXIDATIVE STRESS DISEASES IN PRETERM INFANTS].

Oxidative stress is a state of imbalance between the production of reactive oxygen species and their inactivation by the body's antioxidant systems. Premature babies are susceptible to oxidative stress due to an imperfect antioxidant system. Oxygen resuscitation, respiratory therapy, surfactant use, and other intensive nursing techniques increase the production of reactive oxygen species and increase oxidative stress. The placenta of male and female fetuses have different expression of proteins and genes, which is especially important when exposed to unfavorable factors, because creates the conditions for a survival advantage for female fetuses. The aim of the study was to study the features of the formation of oxidative stress diseases in preterm infants, depending on gender. The results of the management of 324 preterm infants at 24-36 weeks of gestation were analyzed. At the 1st stage of the study, in order to identify the significance of sexual dimorphism in the formation of oxidative stress diseases, the observed children were divided into 2 groups depending on gender. And at the 2nd stage, in order to identify the patterns of the formation of oxidative stress diseases in preterm infants, depending on the state of the ductus arteriosus and gender, each of the groups was divided into 2 subgroups (A and B) depending on the state of the ductus arteriosus: subgroup A - children with the ductus arteriosus spontaneously closed in the neonatal period, and subgroup B - children in whom the ductus arteriosus remained open throughout the child's stay in the perinatal center, including those with a PDA that required surgical closure. At the 1st stage of the study, both groups were relevant in terms of the frequency and severity of respiratory distress syndrome, the frequency of use of surfactant therapy, the frequency and duration of respiratory oxygen therapy, the frequency and severity of BPD, ROP, the frequency of PVL, long-term persistence of the ductus arteriosus and the formation of hemodynamically significant PDA. Group I in comparison with II had a significantly longer gestation period 30,0±0,2 vs 29,2±0,2 (p=0,009), body weight 1429,2±33,6 vs 1230.7±34,8 (p=0,0001) and a higher Apgar score at the 1st minute of life 4,2±0,1 vs 3,8±0,1 (p=0,016). At the 2nd stage of the study, severe RDS was observed significantly more often in group I-B compared with I-A: 59,8% vs 37,4% (p=0,001). The need for respiratory therapy was observed significantly more often among girls with spontaneously closed PDA: in group II-A - 97,2% compared with I-A - 90,9% (p=0,040) and with II-B - 91,9% (p=0,024). The duration of respiratory support was significantly shorter in the group of boys with spontaneously closed ductus arteriosus: in group I-A - 11,8±1,5 compared with II-A - 18,0±2,3 (p=0,019) and with I-B - 17,9±1,9 (p=0,014). The frequency of diagnosis and a severe BPD were recorded among boys with PDA (in group I-B compared with group I-A): 55,0% vs 34,1% (p=0,002) and 21,8% vs 3,3% (p=0,004), respectively. A significantly higher prevalence of ROP, regardless of gender, was observed in the groups of children with spontaneously closed PDA: among boys 89,8% vs 55,0% (p=0.000), among girls 91,7% vs 61,3% (p=0.000). The highest prevalence of grade 3 or more ROP was observed in children with PDA regardless of gender: among boys 43,6% vs 29,1% (p=0,042), among girls 52,6% vs 34,8 (p=0,038). The same incidence of oxidative stress diseases (BPD, PVL, ROP), despite the fact that the group of preterm girls had a significantly shorter gestational age and body weight at birth, indicates a more stable antioxidant system in female newborns with perinatal pathology. When considering the effect of PDA on the formation of oxidative stress diseases in preterm infants, signs of sexual dimorphism were also noted. In the group of boys with PDA, compared with children with spontaneously closed ductus arteriosus, a higher incidence of severe RDS, a longer duration of oxygen therapy, and a higher incidence of severe BPD were revealed. In the group of girls, no similar significant differences were found. ROP grade 3 or more, which requires surgical methods of treatment, was more often observed in children with PDA, regardless of gender.