What are the main causes of persistent occipitoposterior position?

summary

For pregnant women, abnormal fetal position is one of the common factors causing dystocia. In the process of delivery, the fetal head is connected by occipital posterior position or occipital transverse position. In the process of descent, most of the occipital part of the fetal head can turn forward because of strong uterine contraction ° Or 90 °， Turn to occipital anterior position and give birth naturally. If the occipital bone of the fetal head can not turn forward continuously until the late stage of delivery, it is still located in the rear or side of the maternal pelvis, which makes delivery difficult, it is called persistent occipital posterior position or persistent occipital transverse position, then how is it caused?

What are the main causes of persistent occipitoposterior position?

First, due to the occipital position of the fetal presentation is not easy to close to the cervix and the lower uterine segment, often lead to coordinated uterine atony and cervical dilation slow. Because the occipital bone continued to press the rectum behind the pelvis, the puerpera felt that the anus was swollen and defecated, which led to the premature use of abdominal pressure when the cervix was not fully opened.

Second, because the pelvis is characterized by a narrow front half of the entrance plane, which is not suitable for the connection of the fetal head and occipital part, and a wide rear half, the fetal head is easy to be connected by occipital posterior position or occipital transverse position. This kind of pelvis is often accompanied by middle pelvic stenosis, which affects the fetal head to rotate forward in the middle pelvic plane and becomes persistent occipitoposterior position or persistent occipitoposterior position.

Third, the impact of this disease on the mother is that abnormal fetal position leads to secondary uterine atony, prolongs the labor process, often requires surgery midwifery, prone to soft birth canal injury, increasing the chance of postpartum hemorrhage and infection. If the fetal head oppresses the soft birth canal for a long time, it may produce ischemic necrosis and fall off, forming genital fistula.

matters needing attention

The occurrence probability of persistent occipital posterior position and occipital transverse position is not big, but if it occurs, it will cause the risk of pregnant women and infants. Therefore, we must closely observe the labor process, pay attention to the decline of fetal head, cervical dilatation and so on.