A network of muscles provides the main support for the pelvic viscera (the vagina and the surrounding tissues and organs within the pelvis). This network, which is located below most of the pelvic viscera and supports the viscera’s weight, is called the levator ani. Pelvic ligaments provide additional stabilizing support.
When parts of this support network are weakened or damaged, the vagina and surrounding structures may lose some or all of the support that holds them in place. Collectively, this condition is called pelvic floor relaxation. A pelvic organ prolapse occurs when the weight-bearing or stabilizing structures that keep the vagina in place weaken or deteriorate. This may cause the supports for the rectum, bladder, uterus, small bladder, urethra, or a combination of them to become less stable.
Common factors that may cause a vaginal prolapse include the following:
Childbirth (especially multiple births): Childbirth is stressful to the tissues, muscles, and ligaments in and around the vagina. Long, difficult labors and large babies are especially stressful to these structures. Childbirth is the risk factor most commonly associated with cystoceles. A cystocele is a condition in which the bladder prolapses into the vagina. A cystocele is usually accompanied by a urethrocele, in which the urethra becomes displaced and prolapses. A cystocele and urethrocele together are called a cystourethrocele.
Menopause: Estrogen is a hormone that helps to keep the muscles and tissues of the pelvic support structure strong. After menopause, the estrogen level decreases; this means that the support structures may weaken.
Hysterectomy: The uterus is an important part of the support structure at the top of the vagina. A hysterectomy involves removing the uterus. Without the uterus, the top of the vagina may gradually fall toward the vaginal opening. This condition is called a vaginal vault prolapse. As the top of the vagina droops, added stress is placed on other ligaments. Hysterectomy is also commonly associated with a condition called an enterocele, in which the small bowel herniates near the top of the vagina.
Other risk factors of pelvic organ prolapse include the following: