The diaphragm is a shallow dome-shaped cap of latex with a flexible rim. It is filled with spermicide and covers the entry to the cervix, preventing sperm from entering the uterus. It must be combined with spermicidal creams or jellies to prevent pregnancy. A diaphragm should be left in place for six to eight hours after intercourse to be effective. It can be left in place for up to 24 hours at a time.
There are many different sizes of diaphragms. You must visit a doctor or clinic to be examined and measured to find the size that fits you best. You may need to be fitted with a new diaphragm if:
- you gain or lose more than 10 pounds
- it causes pain
- you have a full-term pregnancy, childbirth, an abortion or pelvic surgery
They are 80 to 90 per cent effective against pregnancy but they do not protect you and your partner against sexually transmitted infections. In perfect use, the pregnancy rate is six out of 100 women. In typical use, the pregnancy rate is 12 out of 100. They are a useful solution for women who have sex two or three times a week or less, but they are probably not a good solution for women who have frequent intercourse.
You may not be able to use this method if you have:
- a cervical laceration
- an infection in your cervix or vagina
- an inflammation of the ovaries or fallopian tubes
- physical abnormalities of the cervix or vagina
The first two conditions are temporary. After successful treatment you can use a diaphragm.
Using a diaphragm
- Fill the dome with a teaspoon of contraceptive jelly or cream.
- Squat and open the lips of the vagina.
- Hold the diaphragm, dome down, and squeeze the rim together to form an arc
- Insert the diaphragm into the vagina and push it along the floor of the vagina as far as it will go.
- Tuck the front rim of the diaphragm up behind the pubic bone.
- Check that you have covered the cervix (the smooth bump at the back of your vagina).
- When having intercourse, do not use Vaseline or other oil based lubricants.
Oil-based lubricants can breakdown the latex in your diaphragm.
- If you have intercourse more than once, insert another applicator of spermicide into the vagina.
If the diaphragm has been in longer than two hours before having sex, you must add more spermicide.
Do not remove the diaphragm to add more spermicide
- Leave the diaphragm in place for six to eight hours after intercourse.
Don’t leave the diaphragm in place more than 24 hours unless the six-hour waiting period is not over.
If the diaphragm is dislodged during intercourse you may wish to contact your doctor or clinic and ask that emergency contraception be prescribed.
Caring for a diaphragm
A diaphragm should be washed after each use with a mild non-phosphate detergent and left to dry. It may be dusted with cornstarch to keep it odour free. Keep the diaphragm in its case and away from heat. Hold the diaphragm up to the light to check for holes at least every three months. It should last one to two years.
- it can be inserted hours before intercourse so sex can be spontaneous
- you only use it when you need to
- neither partner can feel the diaphragm
- you control this method of birth control
- it can be used to hold back your menstrual flow if you wish to have sex during your period
- it does not cause any hormonal changes in your body
- must be fitted by a doctor or in a clinic
- is less effective for women who have very frequent intercourse: one study showed that women who had sex more than three or more times a week were more likely to have this method fail.
- causes pelvic pain in some women
- may increase your risk of urinary tract infections
- does not protect against sexually transmitted infections
- some women are uncomfortable inserting and removing it or have difficulty doing so
- spermicidal jellies and cream may cause irritation and often taste bad Vaginal irritation can increase your risk of sexually transmitted infections.
- increased risk of toxic shock syndrome if the diaphragm is left in place too long
- needs to be cleaned after each use
This information is provided by Women’s College Hospital and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: Oct. 29, 2014