Menstruation does not need to be prevented. If a woman has her uterus removed for any of several medical reasons, she will no longer have a period.
Menstruation lasts from puberty to menopause. After menopause, a woman ceases menstruation and can no longer become pregnant.
Menstruation poses no risk to others. Any history of sexually transmitted diseases, including HIV, call for careful disposal of sanitary napkins and good hand washing.