A diaphragm is a dome-shaped device that fits over the cervix to prevent sperm from entering the uterus. In order for a diaphragm to be an effective form of birth control, it must be fitted properly. Your doctor will measure your vagina to find the appropriate fit for you.
When you will have sexual intercouse, apply spermicidal jelly to your diaphragm and insert it into your vagina. Your doctor will walk you through the process of properly inserting and removing your diaphragm.
Your diaphragm should be replaced every 12 to 24 months, and each year you should have it checked to see if it still fits properly. You may also need to be fitted for a new diaphragm if you give birth, have pelvic pelvic surgery or gain or lose more than 15 pounds. Diaphragms are about 86 to 94 percent effective.
Diaphragms do not protect against sexually-transmitted diseases.