Possible predisposing factors include the following.
Hormonal drugs such as oral contraceptives, tamoxifen or hexestrol during pregnancy, or drug factors such as prolonged use of immunosuppressive drugs.
Prolonged irritation of the vaginal wall from the use of a uterine support for the treatment of uterine prolapse, therapeutic factors such as previous surgery, radiotherapy or chemotherapy for other genital tract tumours.
Poor lifestyle such as smoking, history of unclean sex, early sexual debut
Personal factors such as age, family genetics, endocrine regulation, immune deficiency, etc.