A diaphragm is a birth control device that blocks sperm from fertilizing an egg. It is made of rubber and shaped like a dome. It fits inside a woman's vagina and covers the cervix (the opening of the uterus); a firm, flexible rim keeps it in place. A diaphragm is always used with a sperm-killing cream or jelly (spermicide) to prevent pregnancy.

Proper diaphragm use

• Spread spermicidal cream or jelly inside the dome of the diaphragm and around the rim before inserting the diaphragm.
• Fold the diaphragm in half, keeping the edges together and the cream or jelly inside. Insert the diaphragm (with the dome pointing down or backwards) all the way into the vagina, so that the diaphragm covers the cervix. Tuck the forward rim of the diaphragm up behind the bone that forms the front of the pelvis (pubic bone) and the back rim up behind the cervix. The spermicide inside the diaphragm will be held against the cervix.
• Insert the diaphragm no more than 6 hours before having sexual intercourse. The insertion does not have to interfere with sex. Some couples make insertion, which can be done by the man, part of foreplay. Normally, neither you nor your partner will feel the diaphragm during intercourse. If you do feel it, check to make sure it is in position. Also, you may need to make sure the diaphragm is the right size for you.
• Leave the diaphragm in place for 6 to 8 hours after intercourse.
• Do not keep the diaphragm in for longer than 24 hours because of the risk of toxic shock syndrome.

Diaphragm care

• Wash the diaphragm with warm water and hand soap after removing it. Thoroughly dry it and store it in its container. Do not use talcum or baby powder on the diaphragm because these products can break down the rubber.
• Check the diaphragm regularly for holes by holding it up to a light and gently stretching the rubber.

Replacing a diaphragm

With good care, a diaphragm should last 1 to 2 years. You should be refitted for a diaphragm if you gain or lose a lot of weight, have abdominal surgery, or have a baby.