The diaphragm is a bowl-shaped flexible cup that is inserted into the vagina so that it covers the cervix. Commonly used with a spermicidal cream or jelly that kills sperm, the diaphragm stops sperm from entering the uterus.
Spermicidal use is important with diaphragms because they are not completely effective in stopping sperm. When used carefully, diaphragms have been found to be 82-95 percent effective in preventing pregnancy and they may provide some protection from STDs.
Diaphragms must be fitted by a physician to insure that the right size is being used. They can be inserted into the vagina up to six hours prior to intercourse and may be left in place for 24 hours after intercourse (and must be left in place for at least six hours to insure effectiveness).
If intercourse is repeated during this period, additional spermicide can be inserted without removing the diaphragm. Annual gynecological check ups and diaphragm checks are recommended, especially if the woman's weight changes or she recently has had a pregnancy. Potential side effects include irritation, bladder infection, and unusual vaginal discharge.
The most significant potential health risk of using the diaphragm is toxic shock syndrome. Symptoms, which should be reported to one's primary care provider immediately, include vomiting, high fever, diarrhea, a sunburn-like rash, and general itching in the genital area.