What is it?
The diaphragm, cervical cap, and sponge are devices that you place inside your vagina to form a barrier over the cervix. They are sometimes called barrier methods.
- The diaphragm and cervical cap are dome-shaped and made of silicone. The cap covers only the cervix. The diaphragm is larger. It lodges behind your pubic bone. You need to use spermicide with the diaphragm or cap to help prevent pregnancy.
- The sponge is made of thick, soft plastic that covers the cervix. You wet it before placing it in the vagina. The sponge contains spermicide.
How well does it prevent pregnancy?
The diaphragm, cervical cap, and sponge are among the least effective forms of birth control. Pregnancy rates are among the highest for all birth control methods.
The cervical cap and sponge work best if you haven’t given birth. If you have, these methods are less reliable.
During a year of use:
- Diaphragm: About 17 out of 100 women get pregnant.
- Cervical cap: About 13 to 16 out of 100 women who have never had a baby get pregnant, compared with 23 to 32 out of 100 pregnancies among women who have given birth.
- Sponge: About 14 out of 100 women who have never had a baby get pregnant, compared with 27 out of 100 pregnancies among women who have given birth.
HOW DOES IT WORK?
The diaphragm and cervical cap block sperm from entering the uterus through the cervix. The spermicide also slows down or kills sperm. The sponge works mainly by killing sperm.
WHAT ARE SOME PRODUCT NAMES?
Brands sold in the United States include:
- Diaphragm: Milex, Caya
- Cervical cap: FemCap
- Sponge: Today
- All methods are hormone-free.
- Can insert these methods hours ahead of time. This allows sex to be somewhat spontaneous.
- The sponge helps prevent pregnancy for 24 hours after you insert it.
- You can leave the diaphragm in place up to 24 hours and the cervical cap up to 24 hours. With either, you need to insert more spermicide before you have sex again.
- All methods are safe if you breastfeed.
- No prescription needed for the sponge.
- Having sex during your period may be less messy.
- Reversible: Stop using these methods if you want to try to get pregnant.
- Three of the least effective forms of birth control.
- Must use diaphragm, cap, or sponge every time you have sex. Also, must add spermicide with the diaphragm or cap if you have sex again.
- Must leave in place for at least 6 hours after the last time you have sex.
- Can slip out of place during sex. If this happens, you could become pregnant.
- Usually, the diaphragm or cervical cap must be fitted by a doctor or nurse (the exception: one size works for most women with the Caya diaphragm). Also need to recheck size if you have a baby, or gain or lose 10 pounds or more.
- Best to choose another method if you don’t want to put your fingers in your vagina or have problems inserting or removing the device.
- Unless you insert the device ahead of time, putting it in may interrupt sex.
- Cervical cap and sponge don’t work as well if you have had a baby. A diaphragm or cervical cap can tear or get tiny holes. Hold it up to the light to check before each time you use it.
Some women are allergic or sensitive to spermicides. If you feel irritation in your vagina, consider using a different method.