The course of labor with pelvic presentation
Last reviewed: 19.10.2021
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Births with pelvic presentation of the fetus are most often complicated:
- premature or early discharge of amniotic fluid, prolapse of umbilical cord loops;
- weakness of labor activity;
- asphyxia of the fetus;
- unpreparedness of the soft tissues of the birth canal for the passage of the head.
Due to the nature of the course of labor during pelvic presentations of the fetus, it is necessary to perform the following measures: prevention of untimely discharge of amniotic fluid; early detection of abnormalities of labor and their timely treatment; rendering in manual delivery manuals for NA Tsovyanov and classical manual allowance.
The mechanism of labor in pelvic presentation differs from that in headache, but the principle of adapting the presenting part to the generic canal remains the same.
Buttocks are smaller in volume than the head, but still they are for the mother's pelvis a large part. The largest size of the buttocks is the distance between the large spits. This size, like a sagittal seam in the head preposition, is set in the normal pelvis input in an oblique size. The front buttock of the first falls into a small pelvis, becoming a leading point in front. Thus, a moment is made that can be likened to a sacral rotation in the head preposition.
When the largest volume (segment) of the buttocks passes through the pelvic inlet, the latter perform an internal rotation in the pelvic cavity in such a way that the anterior buttock approaches the forehead and extends forward, and the posterior goes to the sacrum; lin. The inteitrochanterica is set on the pelvic floor in a direct exit size.
As for the cutting and cutting of the buttocks, this moment is accomplished as follows. The anterior butt emerges from under the symphysis, the fetus basin rests in the lumbar arch with its ilium (fixation point) and only then the posterior buttock is born. In this case, a strong lateral flexion of the lumbar spine along the pelvic axis occurs, similar to extension of the head.
When the posterior buttock is fully born, the arch of the spine straightens, releasing the rest of the anterior buttock. The legs at this time or are also released if they go along with the buttocks, or they stay in the birth canal if they are extended, which is usually observed with a purely breech presentation. In the latter case, the legs are born during the following bouts. After birth, the buttocks make an external turn (similar to the head) according to the position of the overlying shoulders. Lin. Intertrochanterica is set in the same size as the shoulders. The birth of the trunk from the buttocks to the shoulder girdle is easy, since this part of the body is easily compressed and adapted to the birth canal. At the same time, the umbilical ring is shown, and the umbilical cord is pressed to the trunk with the muscles of the pelvic floor.
Passage of the shoulder girdle through the birth canal is of the same type as the passage of the pelvic end. Bicromial size of the shoulders can not be established in a direct exit size. The front acromion is released from the womb, as a result of which the neck-shoulder angle (the fixation point) is established under it, and only after that the hindleg is released. In this case, the handles are born easily if they maintain a normal member position, or are delayed when they are extended along the head or reclined behind it. Extended or overturned handles can be released only by obstetric methods. Born shoulders according to the mechanism of passage through the pelvis of the subsequent head make an external turn into an oblique dimension, opposite to that in which the arrow-shaped seam is located.
At a birth of a head there is a flexion in an input or entrance in a basin in which she comes in an oblique size; followed by an internal rotation in the pelvic cavity, incision with a larger circumference corresponding to the diameter of the suboccipito-frontalis.
The fixation point is the suboccipital fossa, with the occipital hillock being set higher than the bosom; the head is bent, the chin is born first, the occiput is the last.
Every obstetrician should be able to help with childbirth in pelvic presentation. The obstetrician must remember that a dangerous period that threatens the fetus begins with the moment when the lower angle of the scapula appears from the genital slit. At this point, the delay in labor, at least for a short period, on average not exceeding 5 minutes, is fatal to the fetus. This danger can occur even after the umbilical ring emerges from the genital slit due to the pressing of the umbilical cord. Especially the greatest danger threatens the life of the fetus during passage through the output of the pelvis of the shoulder girdle, when the head enters the cavity of the small pelvis.