A diaphragm is a rubber cup made of latex or silicone. It is a temporary method of contraception that has been used by women for decades.

Placed over the cervix (the opening of the uterus that separates the vagina from the uterine cavity), a diaphragm is used to stop sperm from entering the uterus and fallopian tube. This is the path where sperm normally travels to fertilize a woman’s egg. The device should always be used in combination with a spermicide cream or gel. When these birth control creams are placed in the diaphragm and along its rim, the spermicide destroys any sperm that may manage to swim around the rim of the diaphragm. A diaphragm does not protect women from sexually transmitted diseases (STDs). To prevent STDs, a condom must be worn by the woman’s partner.

Diaphragms come in many different sizes and types. The four main types include:

• Arcing spring rim diaphragm
• Flat spring rim diaphragm
• Coil spring rim diaphragm
• Wide-seal rim diaphragm

A diaphragm is available only by prescription. A woman is fitted for the device in her physician’s office, usually by her gynecologist. The fit of the diaphragm should be checked every year because changes in the size or shape of the vagina or position of the uterus may cause the diaphragm to fit incorrectly. A number of factors may cause the vagina to change shape or size, including pregnancy and changes in weight.

A diaphragm must be placed into the vagina and onto the cervix before sexual intercourse. It can be inserted up to six hours before sex. Some women use a plastic tool known as an introducer to insert the diaphragm, while others can insert the diaphragm with their fingers. Women may have intercourse several times while wearing a diaphragm. However, additional spermicide should be added each time. After intercourse, the diaphragm must remain in place for at least six hours to prevent pregnancy. It must be removed within 24 hours in order to prevent complications, including urinary tract infections and toxic shock syndrome (TSS).

The Food and Drug Administration (FDA) estimates that approximately 17 percent of women who rely on the diaphragm for contraception have an accidental pregnancy each year. To avoid unplanned pregnancy, a woman must wear the device every time she has intercourse, use spermicide and ensure the device is positioned correctly over the cervix.