A presentation and a cord prolapse

Prolapse of the umbilical cord is called finding it ahead predlagay part (or near it) when retired waters, i.e. when disturbed intact membranes.
If the integrity membranes are intact and ahead predlagay parts are umbilical cord loops, talk about the presentation of the umbilical cord.
Thus, clinically it is necessary to distinguish two concepts - previa (praesentatio funiculi) and loss (prolapsus s. apothesis funiculi umbilicalis) of the umbilical cord (Fig. 102A, b). In both types the wrong provisions of the umbilical cord has a direct threat to the life of the fetus, but when the cord prolapse she is the greatest. However, if to take timely measures, the fetus is able to save.

Fig. 102. Previa (a) and precipitation (b) of the umbilical cord.

The main reason of falling of the umbilical cord is insufficient closing the entrance to the pelvis predlagay part, for the more perfect expressed zone of contact predlagay part of the fruit with the walls of the birth canal, the less reason for the fall of the umbilical cord. The cord prolapse contributes to the wrong position, or the presentation of the fetus.
When you cross the fetal position the lower uterine segment almost completely empty, and so the cord prolapse in such cases occurs most frequently.
When the pelvic presentation in the lower uterine segment of free space is less than a foot previa.
Therefore, at the foot previa frequency of dealing umbilical cord is many times more than during the buttocks.
When the head previa a cord prolapse is rare, as thick and bulky head well closes the entrance to the pelvis. Only with the narrow basins, in which, as is known, the head for a long time is not fixed at the entrance to the basin, resulting in between the head and the wall of the lower uterine segment remains free period, favorable conditions are created for the fall of the umbilical cord (C. I. Gusev, 58%).
However, not only narrow, but overly broad pelvis may be the proximate cause of prolapse of the umbilical cord.
Among other things, contributing to the cord prolapse, plays the role of the placenta previa, eccentric (century, especially regional) attaching the umbilical cord to the placenta and the excessive length of the cord. But the most frequent time, contributing to the deposition is delayed discharge of amniotic fluid, which runs from the uterus, carry the umbilical cord (by C. Y. Gusev - in 67% of cases).
Hence it is clear what should be concerned doctors management of deliveries with polyhydramnios and multiple pregnancy.
The frequency of this complication ranged from 0.73% (B. N. Mikhailov) to 0.62% (C. I - Gusev).
Prolapse of the umbilical cord at multiparous occurs more frequently in connection with the fact that predlagaemaya part is usually a very long time movable over the entrance to the pelvis.
The danger to the fetus when the cord prolapse depends on pressure dropped its hinges, moving through the birth canal predlagay part to the pelvic wall. As a result of this comes the difficulty or complete cessation of circulation of blood in the umbilical cord and the death of the fetus from asphyxia.
The degree of pressing the cord at departed waters and the rolling predlagay part depends on the strength of labor activity. In the complete absence of labor dropped the cord may long to be free from pressure. When the pelvic previa the umbilical cord squeezed less than at the head, and therefore in such cases the fruit more often is born alive.
In the death of the fetus is not only the compression of blood vessels, but also cooling and mechanical irritation fallen umbilical cord loops, which in turn causes a reflex spasm of blood vessels of the umbilical cord.
The recognition. To determine the cord prolapse without vaginal studies is not easy even when retired waters since dropped out of the loop is not always appear from the genital slit; they can remain in the vagina.
In some cases fallen loop umbilical seen during the inspection, and in others it is recognized only when vaginal examination.
When vaginal examination, the umbilical cord is defined as thin smooth lace giving (if living fetus) a sense of pulsation.
To eliminate the cord prolapse after ruptured membranes at mobile predlagay part, should immediately make vaginal examination. To install this complication in those circumstances, only listening to the fetal heart impossible.
Finding the vagina loose umbilical obliges find out whether its compression or not. About it is judged by the presence of pulsation of the umbilical vessels, what determines the choice of obstetric surgery.
To the assessment of pulsation should be approached with great caution. The absence of pulsation not always proves that the death of the fetus. Sometimes the cord is severely constrained, and the fetus is still alive, rather, live the last minute. When non-pulsating umbilical cord, but if you have heart sounds fruit may be saved, if quickly and skillfully of adorability woman. Usually after a complete compression of the umbilical cord death of the fetus occurs in 3-5 minutes