What are the causes of anterior and posterior vaginal wall prolapse?

1. The bottom of the bladder and the urethra are close to the anterior vaginal wall. The supporting tissues of the anterior vaginal wall are mainly the pubovesical cervical fascia and the deep urogenital fascia. The former extends forward and outward along the bottom of the bladder from the pubic symphysis to the pubic arch and attaches to the anterior cervix. The fascia around the vagina connects upward to the fascia around the cervix and meets the cardinal ligaments. The pubocervical ligaments on both sides of the cervix also play an important role in maintaining the normal position of the bladder.

2. When the fetal head passes through the vagina during childbirth, the pubovesical cervical fascia and the pubococcygeal muscles inevitably stretch excessively or even tear. For example, if rest is inadequate during the puerperium, especially if physical labor is resumed too early, the vaginal supporting tissues may fail to recover normally. This can cause the bladder and the anterior two-thirds of the adjacent vaginal wall to bulge downward, known as cystocele. If the anterior segment of the pubovesical cervical fascia is damaged, the urethra and the inferior one-third of the adjacent anterior vaginal wall, with the urethral orifice as a fixed point, may rotate backward and descend, forming a urethrocele.