what is a diaphragm? what does it do?

A diaphragm is a form of birth control that is a shallow, dome-shaped cup made of soft silicone or latex that is inserted into the vagina to cover the cervix during sex. It works as a barrier that prevents sperm from joining an egg, thus helping to prevent pregnancy. To be effective, a diaphragm must be used with spermicide, a chemical that kills sperm. The diaphragm is placed high into the vagina so it covers the cervix and is held in place by the vaginal muscles. Some possible side effects of using a diaphragm include irritation of the vagina and surrounding skin or an allergic reaction from the spermicide, strong odors or vaginal discharge if the diaphragm is left in too long, a higher risk for urinary tract infections (UTIs), and toxic shock syndrome if the diaphragm is left in too long. Some disadvantages of using a diaphragm include that it is not as effective as other types of contraception, it does not provide reliable protection against sexually transmitted infections (STIs), it can take time to learn how to use it, and putting it in can interrupt sex.