Overview

The diaphragm is used to prevent pregnancy. It is called a barrier method because it keeps the sperm and eggs apart. It is usually made of silicone and shaped like a dome, and it has a firm, flexible rim. It fits inside your vagina and covers the cervix, which is the opening of the uterus.

You use the diaphragm each time you have vaginal sex. You must use spermicide with it.

Before vaginal sex, apply spermicide to the diaphragm and place it in your vagina. If you have sex more than 1 to 2 hours after placement, apply more spermicide to your vagina. If you have sex more than one time when the diaphragm is in place, apply more spermicide each time. Leave the diaphragm in place for at least 6 hours after sex. Do not leave it in for more than 24 hours.

You need a prescription from your doctor for a diaphragm. Depending on the type of diaphragm, you may need to be fitted for the right size by your doctor. A diaphragm will last for 1 to 2 years.

How well does it work?

In the first year of use:

• When the diaphragm with spermicide is used exactly as directed, it is about 84% effective for preventing pregnancy. This means that about 16 out of 100 people who use it will have an unplanned pregnancy.^{footnote 1}
• When it is not used exactly as directed, it is about 83% effective. This means that about 17 out of 100 people who use it will have an unplanned pregnancy.^{footnote 1}

There is less chance of getting pregnant if you and your partner use an external (male) condom with the diaphragm.

Be sure to tell your doctor about any health problems you have or medicines you take. Your doctor can help you choose the birth control method that is right for you.

What are the advantages of using a diaphragm for birth control?

• The diaphragm doesn't use hormones. So you can use the diaphragm if you don't want to take hormones or can't take hormones because you have certain health problems or concerns.
• The diaphragm is safe to use while breastfeeding.
• It doesn't affect your menstrual cycle.
• It costs less than hormonal types of birth control.
• The diaphragm can be inserted up to 6 hours ahead of time so you don't have to interrupt sex.
• The diaphragm can't be felt by you or your partner.

What are the disadvantages of using a diaphragm for birth control?

• The diaphragm doesn't prevent pregnancy as well as IUDs or hormonal forms of birth control.
• It prevents pregnancy only if you use it every time you have intercourse.
• The diaphragm doesn't protect against sexually transmitted infections (STIs), such as herpes or HIV. If you're not sure whether your partner might have an STI, use a condom to protect against infection.
• The diaphragm may cause you to get more bladder infections (urinary tract infections, or UTIs). This is probably because the rim of the diaphragm presses on the urethra and may irritate it. If you get frequent UTIs, you may need a smaller diaphragm or may prefer to use a different type of birth control.
• You may have to interrupt sex to insert the diaphragm. You also have to put spermicide in it every time you use it. Spermicide may cause an allergic reaction. It can cause itching or sores in the vagina or on the penis.
• You may not be comfortable with inserting the diaphragm each time you have intercourse.

If you think you used the diaphragm incorrectly, you can use emergency contraception to help prevent pregnancy. The most effective emergency contraception is an IUD (inserted by a doctor). You can also get emergency contraceptive pills. You can get them with a prescription from your doctor or without a prescription at most drugstores.