Functional and morphological changes in the mother-placenta-fetus system during chronic hypoxia (experimental study)

摘要

The aim of work was to study the characteristics of uteroplacental blood flow in pregnant rats, tissue oxygenation and themorphological features of the main internal organs (heart, liver, kidneys) of newborns during chronic intrauterinehypoxia. The rats (8 animals) were divided into 2 experimental groups. The first (hypoxia) group was subjected tohypoxia throughout pregnancy (21 days). The second (control) group was not exposed to any effect throughout thepregnancy. On the 20th day of gestation in both groups, a Doppler ultrasound study of uterine-fetal blood flow andmeasurement of the placenta was performed. Newborn rat pups of the first day of life were subjected to oxygenationdegree measurement. After delivery, the number of rats in the litter was counted and their body weight was measured.After the measurements the laboratory animals were withdrawn from the experiments and morphological study of theirinternal organs was performed. The studies have shown a clear relationship between the characteristics of uterine bloodflow and the presence or absence of hypoxia. In chronic hypoxia, there were low rates of arterial blood flow, an increasein the peripheral resistance of uterine vessels. All this indicates the defective formation of the placenta and impairedblood flow with the development of placental insufficiency. It was also found that hypoxia in the antenatal periodadversely affects the number and somatometric indicators of newborn rats in the offspring. Histological examination ofthe tissues of the heart, liver and kidney of newborn rat pups showed signs of impaired blood circulation, dystrophic andnecrobiotic changes in the parenchyma.