sexual intercourse is the cause of 75–90% of bladder infections in young, sexually active women. the risk of infection is related to how often they have sex. with utis so frequent when women first get married, the term "honeymoon cystitis" is often used. in post-menopausal women (women who have stopped menstruating), sexual activity does not affect the risk of developing a uti. using spermicide (a gel or cream to kill sperm) increases the risk of utis.