It is important to note that studies aimed at studying the architectonics of myometrium and anatomo-histological studies of the structure of the uterus showed that the uterus, by the end of the pregnancy, increases along the length to 36 cm, its width reaches 25 cm, the thickness (anterior-posterior diameter) of the body to 24 cm .
The pathology of the placenta, including its insufficiency in the structure of the causes of perinatal pathology and mortality is 20-28%. Chronic insufficiency of the placenta against the background of a high degree of its immaturity and the violation of compensatory-adaptive mechanisms, primarily vascular, can lead to absolute placental insufficiency and numerous complications in childbirth.
Primary weakness is observed in cases of weakness in the muscles of the abdominal press in multifaceted women with excessively stretched and relaxed abdominal muscles, with infantilism, obesity, as well as abdominal wall defects in the form of hernia of the white abdominal line, umbilical and inguinal hernia, with myasthenia, with spinal injuries.
Weakness of labor is a condition in which the intensity, duration and frequency of contractions are insufficient, and therefore smoothing the cervix, opening the cervical canal and moving the fetus, when it corresponds to the pelvic size, is slow.
For the successful development of scientific and practical obstetrics, it is of fundamental importance to elucidate the causes of anomalies of labor and the most reasonable pathogenetic treatment.
For the speed of lowering the present part of the fetus, these boundaries are respectively equal to 6.4 and 14.0 cm. Therefore, for practical purposes, it should be considered that rapid delivery (not to be confused with a rapid birth) is characterized by the rate of opening the cervix and lowering the presenting part of the fetus, exceeding 5 cm / h in primiparas and 10 cm / h in the miscreant.
Delayed lowering is a pathologically slow rate of lowering the presenting part of the fetus. The definition of this condition varies depending on the number of births in a woman - in primiparas, the presence of such anomaly is indicated by the maximum slope on the curve of the lowering of the presenting part of the fetus, equal to 1 cm / h or less
As is known, the most significant lowering of the presenting part of the fetus occurs at the end of I and especially in the second stage of labor. Therefore, the impossibility of further fetal progression, stopping or slowing down of the fetus are typical violations of the II period of labor.
Excessive labor activity (uterine hyperactivity) is a form of an abnormality of labor, which is manifested by excessively strong contractions (more than 50 mm Hg) or by fast alternations of contractions (more than 5 contractions per 10 min) and increased uterine tone (more than 12 mm Hg. St.).
Under the discoordination of labor, we understand the absence of coordinated contractions between the different parts of the uterus: the right and left halves of the uterus, the upper half (the bottom, the body) and the lower parts of the uterus, between all parts of the uterus.