Diaphragm

The diaphragm is a soft flexible rubber cup shaped like a dome that is inserted into the vagina. The diaphragm blocks access to the cervix so that sperm cannot pass from the vagina into the uterus. The diaphragm must be covered on both sides and especially around its rim with spermicidal jelly, cream, or foam in order to form a tight seal around the diaphragm.
A woman inserts the diaphragm into her vagina no more than 4 hours prior to intercourse. After intercourse, she should check to be sure that the diaphragm has not been dislodged and is still in the correct position. The diaphragm must be left in place for at least 6-8 hours after intercourse; after this time it should be removed. Fresh spermicide jelly or foam must be inserted into the vagina each time intercourse is repeated.
Since diaphragms are only available with a prescription, a woman must see a health care practitioner to have a diaphragm properly fitted (they come in a range of sizes), and to learn proper insertion techniques. There are no known long-term health risks associated with using the diaphragm and spermicide method of birth control. Some women may find spermicides to be irritating, but changing brands of spermicides may help. There is also an increased risk of urinary tract infections with diaphragm use. One possible reason is that the diaphragm puts increased pressure on the urethra or the spermicide may contribute to irritation leading to infection. (The cervical cap is not associated with increases in urinary tract infections.)
The diaphragm may be appealing to women because it offers a safe temporary (not permanent) birth control that is under her control.
When the diaphragm and spermicide are used correctly, they are thought to have over an 82% success rate (18 pregnancies/100 women per year). To ensure protection, it is important that the diaphragm be checked after every use for rips or holes (this is best done by holding the diaphragm up to the light). Also, the fit of the diaphragm should be checked annually, after every pregnancy, and after significant weight loss.
Using a diaphragm does not protect a woman from sexually transmitted infections, although the spermicide does give partial protection against gonorrhea and chlamydia. It can, however, be used with condoms to offer some protection against sexually transmitted infections.