The soft birth canal includes the lower uterine segment, cervix, vagina and vulva. Lesions in the soft birth canal itself can cause obstructed labor, and lesions in and around other parts of the genital tract can also affect the soft birth canal and make labor difficult, but the former is more common. The obstructed labor due to soft birth canal abnormalities is much less common than that due to bony birth canal abnormalities, so it is easy to be overlooked, resulting in missed diagnosis. Therefore, vaginal examination should be performed routinely in early pregnancy to find out whether there are any abnormalities in the genital tract and pelvis. Since abnormalities of the soft birth canal can also cause obstructed labor, it is of clinical significance to perform a vaginal examination in early pregnancy to understand the condition of the vulva, vagina and cervix, as well as any other abnormalities of the pelvis. The following diseases may also be the cause of soft birth abnormalities: 1. dystocia is an obstetric disease in which the opening period of labor (first stage), especially the fetal expulsion period (second stage), is significantly prolonged due to various reasons, and the mother has difficulty or cannot expel the fetus without artificial assistance. If the obstructed labor is not handled properly, it can not only cause diseases in the reproductive tract of the mother animal and affect the fertility in the future, but also may endanger the life of the mother and the fetus. 2, uterine prolapse The uterus descends from its normal position along the vagina, and the external cervical opening reaches below the level of the sciatic spine, or even the uterus is completely prolapsed outside the vaginal opening, which is called uterine prolapse. Uterine prolapse is often combined with bulging of the anterior and posterior vaginal walls. 3, persistent occipitoposterior obstructed labor persistent occipitoposterior is due to the delivery, the fetal head to the occipital posterior articulation, in the process of descent, when the fetal head biparietal diameter reaches or close to the mid-pelvic plane, the vast majority can complete the internal rotation action, into the occipitoposterior position natural delivery. 5% to 10% until the end of labor, the fetal head occipital continued not to In 5%-10% of cases, the occipital part of the fetus cannot be turned to the front until the end of labor, and is still located in the posterior part of the maternal pelvis. 4, abnormal obstructed labor Bone birth canal abnormality means pelvic stenosis. The shortening of any one or several trajectories of the pelvis is called pelvic stenosis. The pelvis can be narrowed in one or more of the three planes: entrance, mid-pelvis and exit. When one pathway is narrowed, the size of the other pathways in the same plane needs to be observed, and then the size and morphology of the entire pelvis needs to be measured comprehensively in order to estimate more correctly the impact of this pelvis on the composition of obstructed labor. What is often encountered in clinical practice is a critical or mild pelvic stenosis, and whether it constitutes a difficult labor is closely related to the size and position of the fetus, the plasticity of the fetal head, labor force, soft tissue resistance, and whether the treatment is timely and correct. In addition, the deformed pelvis caused by congenital developmental abnormalities and acquired diseases is also a bone birth canal abnormality. 5, labor abnormalities obstructed labor Labor abnormalities refer to abnormal uterine contractions, often resulting in obstructed labor. Uterine contraction force abnormalities can be primary, but also due to abnormalities in the birth canal or fetal factors that make it difficult for the fetus to pass through the birth canal (forming obstructive obstructed labor) and lead to secondary contraction force.