What causes vaginal prolapse?

Multifactorial. Multiple factors that can cause prolapse. Most women have one or more: number of pregnancies/ vaginal deliveries, weight of baby at birth, large tears at delivery, family history, smoking, obesity, diabetes, chronic coughing/sneezing/heavy lifting, connective tissue disorders.
Childbirth. Vaginal prolapse is due to relaxation of the pelvic floor muscles. Although some studies have found up to 25% of female college athletes have stress incontinence, a common symptom of pelvic relaxation, the most common cause of pelvic floor muscle relaxation is pregnancy and especially childbirth.
Injury. Prolapse of the pelvic floor includes weakness or injury to one or more of 7 different areas. These include the support of the bladder neck and base, the uterus or vaginal cuff, the rectum, the vaginal sidewalks, the small bowel and the vaginal opening. Damage to the connective tissues and ligament support usually occurs with pregnancy and childbirth.