For good birth control, your diaphragm (see picture 1) has to fit well. Your doctor will measure your vagina to find the correct size and fit for you.

Your doctor or a nurse will teach you how to put the diaphragm in and take it out. You also should read the directions from the company that made your diaphragm.

To be sure that you know how to use your diaphragm, you will need to practice putting it in and taking it out while you are in your doctor's office. Your doctor also might check to see that the diaphragm fits right.

To keep from getting pregnant, it is important that you use your diaphragm correctly—and that you use it every time you have sex. You can put the diaphragm in your vagina right before you have sex or up to 6 hours before you have sex.

Getting Your Diaphragm Ready

Before you put the diaphragm in your vagina, put about 1 teaspoon of spermicidal gel (or cream) in the cup, also called the dome (see picture 2). Smear some more gel around the rim of the diaphragm. Do not use petroleum jelly or oil-based vaginal creams, such as Monistat. These can make tiny holes in the diaphragm.

Inserting Your Diaphragm

You can put your diaphragm in while you are lying down, squatting, or standing with one leg up on a chair. Your legs need to be fairly wide open. Bending your knees and hips can help.

• Use one hand to fold the diaphragm in half with the dome pointing down, as if to enclose the spermicidal gel (see picture 3). Hold your vagina open with your other hand.

• Put the diaphragm into your vagina, aiming for your tailbone (see picture 4). Push the diaphragm as far back into your vagina as you can.

• Use one finger to push the front rim of the diaphragm up behind your pubic bone, aiming for your belly button.

Checking Placement of Your Diaphragm

With your finger, feel for your cervix through the dome of the diaphragm. The cervix is firm but not bony. It feels a bit like the tip of your nose.

If the diaphragm does not cover your cervix or you cannot feel your cervix at all, the dome is not in the right place. This means that you need to remove the diaphragm, put more spermicidal gel on it, and insert it again.

The diaphragm should not fall out when you cough, bear down, sit on the toilet, or walk around. If your diaphragm stays in place when you do these things, the front rim is most likely above the pubic bone—where it should be (see picture 5).

After You Have Sex

Here are some important points to remember:

• Leave the diaphragm in place for at least 6 hours after you have sex.

• If you have sex again during this time, put spermicidal gel in your vagina, but do not take your diaphragm out to put gel in the dome.

• Do not douche while the diaphragm is in your vagina.

• Take the diaphragm out of your vagina 6 to 12 hours after you have sex.

• Do not leave the diaphragm in your vagina for more than 24 hours. Doing so can cause infection, irritation, or even toxic shock syndrome.

To remove the diaphragm, “hook” the front rim with your finger and pull down and out. If you have long fingernails, be careful that you do not put a hole in the diaphragm.

Taking Care of Your Diaphragm

After you take the diaphragm out of your vagina, wash it with mild soap and water, rinse it, and dry it well. Always store your diaphragm in its container, away from sunlight and out of the air.

You need to check your diaphragm often for holes. To do this, fill the dome with water and look for tiny leaks.

Your diaphragm may last several years. Every year, your doctor should check to see that your diaphragm still fits right. You will need to be measured again if you have a baby, have pelvic surgery, or gain or lose more than 15 pounds.

Call Your Doctor—

Call your doctor if you have any of these problems:

• Trouble urinating, or painful or frequent urination

• Vaginal itching, discharge, or discomfort

• High fever (which can be a sign of toxic shock syndrome)

You also should call your doctor if your diaphragm falls out, is punctured, or does not seem to fit right. If your diaphragm has any of these problems, it needs to be replaced. If you keep using it as is, you could get pregnant.