FETA HYPOXIA - A pathological condition that occurs when there is an insufficient supply of tissues and organs of the fetus with oxygen. Acute hypoxia occurs during childbirth (with anomalies of labor, loss or compression of the umbilical cord, prolonged compression of the fetal head in the pelvic cavity), less often during pregnancy (with uterine rupture, premature detachment of the placenta, etc.) important organs. Chronic hypoxia can be observed with extragenital diseases, toxicosis of pregnant women, prolonged pregnancy, maternal and fetal blood incompatibility, infection of the fetus, etc. It develops gradually, therefore the fetus adapts to moderate oxygen deficiency.
The severity of changes that occur in the body of the fetus during hypoxia is determined by the duration and intensity of oxygen deficiency. Severe oxygen deficiency leads to a significant impairment of blood circulation and microcirculation: the fetus has a short-term increase in blood pressure, tachycardia , which are replaced by a decrease in blood pressure and bradycardia; there is a thickening of the blood due to the release of plasma beyond the vascular bed, tissue edema develops; increased permeability and fragility of the vascular wall lead to hemorrhages. The accumulation in the tissues of acidic metabolic products (acidosis) and a change in the electrolyte balance under the influence of oxygen deficiency lead to intracellular edema. All these changes disrupt the function of vital organs, which can lead to fetal death, asphyxia of the newborn or intracranial injury.
The main clinical signs of acute hypoxia are abnormal fetal cardiac activity (increased heart rate more than 160 beats per 1 minute or a decrease to 120 or less beats per 1 minute, arrhythmia, and deafness of tones), pronounced increase or a sharp weakening of its motor activity. Chronic hypoxia, as a rule, can be diagnosed using special methods of research. In addition to auscultation, electrocardiography, phonocardiography, and cardiac tachography (registration of the fetal heart rate using cardiac monitors) are used to study fetal cardiac activity. Ultrasound scanning can detect fetal abnormalities inherent in hypoxia. An important sign of acute and chronic hypoxia is the admixture of meconium in the amniotic fluid, which is determined upon examination in the event of their discharge or amnioscopy (the study of fetal membranes and amniotic fluid using a special optical device introduced into the cervical canal). In the biochemical study of amniotic fluid obtained by amniocentesis, in the case of chronic hypoxia, a decrease in their pH (less than 7.01), an increased concentration of carbon dioxide, changes in enzymatic activity and hormone levels are noted.
If you suspect chronic hypoxia (toxicosis of pregnant women, extragenital diseases of a woman, etc.), a pregnant woman should be hospitalized to study the condition of the fetus, to determine the cause of hypoxia. Measures aimed at improving the uteroplacental circulation and the normalization of fetal metabolic processes can be carried out on an outpatient basis as prescribed by a doctor. These include ultraviolet radiation, the introduction of partusisten, aminophylline, complamine, inhalation of 40 - 60% oxygen-air mixture, etc.
When signs of acute hypoxia appear, urgent hospitalization of the pregnant woman and urgent emergency measures to combat hypoxia during transportation are necessary. Inhalation for 20–30 minutes of a moistened 60% oxygen-air mixture with simultaneous intravenous administration of 50 ml of 40% glucose solution with 300 mg of ascorbic acid and 1 ml of cordiamine (Nikolayev’s method) to a woman has a favorable effect. Inhalations of an oxygen-air mixture have the best effect after prior intravenous or intramuscular administration of antispasmodics to a woman (1 ml of a 2% solution of papaverine hydrochloride, 2 ml of a 2% no-solution). Sypetin is effective (2–4 ml of 1% solution in 20–40 ml of 20% glucose solution intravenously), cocarboxylase (100 mg intramuscularly or intravenously).
If acute hypoxia occurs during childbirth, it is necessary to eliminate, if possible, the cause of this pathological condition; simultaneously carry out the above therapeutic measures. In the absence of the effect of therapy, it is necessary to promptly raise the issue of operative delivery (obstetric forceps, vacuum extraction, cesarean section, etc.).
Prevention of fetal hypoxia begins in the antenatal clinic. It includes the early detection and treatment of extragenital diseases of a pregnant woman, pregnancy complications, and control of the fetus. Of great importance is the correct management of labor, including timely diagnosis and adequate treatment of complications that arise, and constant monitoring of the condition of the fetus.