The contraceptive sponge is a doughnut shaped sponge. It is made of polyurethane foam and is impregnated with the spermicide Nonoxynol-9. This spermicide is essential to the contraceptive ability of the sponge.

Before intercourse, a woman pushes the sponge up into her vagina much as she would insert a tampon. The spermicidal sponge should then act as a barrier in order to prevent sperm from reaching the cervix. Once in place, the sponge provides protection for up to 24 hours without the need for additional spermicide.

The sponge must remain in the vagina for at least 6 hours after intercourse. However, the same sponge should never remain in the vagina for more than a total of 30 hours because of the risk of toxic shock syndrome. (Toxic shock syndrome is an uncommon and potentially very serious illness that is caused by a type of bacteria. This illness occurs when certain types of products, such as tampons, are left in place for excessive periods of time. This is why package instructions of these products are careful to specify how long they may be safely kept in place.) Each sponge is used only once and then thrown away.

The sponge is generally an effective birth control method. Some users of the contraceptive sponge may experience irritation and allergic reactions. The sponge can also be difficult to remove from the vagina. Removal has been made easier by the addition of a woven polyester loop.

The contraceptive sponge is intended to be sold over-the- counter (OTC) and does not require a prescription. When first approved by the FDA, the sponge became the most popular OTC contraceptive product for women. Then, in 1995, the sponge was removed from the market because the manufacturer was having economic problems. The FDA approval of the sponge remained in effect. The original manufacturer of the sponge has been acquired by another company and the sponge is not yet available for purchase. The estimated effectiveness of the sponge as a contraceptive is 64 to 82%. As for protection from sexually transmitted infections, the spermicide may provide some protection against chlamydia and gonorrhea, but otherwise, the degree of protection is unknown.

Diaphragm

The diaphragm is a soft flexible rubber cup shaped like a dome that is inserted into the vagina. The diaphragm blocks access to the cervix so that sperm cannot pass from the vagina into the uterus. The diaphragm must be covered on both sides and especially around its rim with spermicidal jelly, cream, or foam in order to form a sperm- tight seal around the diaphragm.

A woman inserts the diaphragm into her vagina no more than 4 hours prior to intercourse. After intercourse, she should check to be sure that the diaphragm has not been dislodged and is still in the correct position. The diaphragm must be left in place for at least 6 hours after intercourse and it can be left in for up to 24 hours. Fresh spermicide jelly or foam must be inserted into the vagina each time intercourse is repeated.

Since diaphragms are only available with a prescription, a woman must see a health care professional to have a diaphragm properly fitted (they come in a range of sizes), and to learn proper insertion techniques. There are no known long-term health risks associated with using the diaphragm and spermicide method of birth control. Some women may find spermicides to be irritating, but changing brands of spermicides may help. There is also an increased risk of urinary tract infections with diaphragm use. One possible reason is that the diaphragm puts increased pressure on the urethra and another culprit may be the spermicide. (The cervical cap is not associated with increased urinary tract infections.)

The diaphragm may be appealing to women because it offers a safe temporary (not permanent) birth control that is under her control.

When the diaphragm and spermicide are used correctly, they are thought to have over an 82% success rate (18 pregnancies/100 women per year). To ensure protection, it is important that the diaphragm be checked after every use for rips or holes (this is best done by holding the diaphragm up to the light). Also, the fit of the diaphragm should be checked annually, after every pregnancy, and after significant weight loss.

Using a diaphragm does not protect a woman from sexually transmitted infections, although the spermicide does give partial protection against gonorrhea and chlamydia. It can, however, be used with condoms to offer some protection against sexually transmitted infections.

Cervical Cap

The cervical cap is a small (1-1/2 inches or about 3 cm.), thimble-shaped dome made of latex rubber (it is much smaller than a diaphragm) and it fits right over the cervix. The cervical cap is used along with a spermicide. One small application of spermicide is placed inside the cap at the time of insertion. The cap + spermicide prevent sperm from going through the cervix and entering the uterus.

A woman pushes the cervical cap up her vagina and into position over her cervix. It can remain in place for up to 48 hours. Unlike the diaphragm, fresh spermicidal jelly or foam does not need to be added each time intercourse is repeated as long as the cervical cap is correctly positioned over the cervix.

The idea of using a cervical cap is not new, it is thousands of years old. Even in ancient times, women devised ways to block off their cervix. One type of cap, the Prentif, has been manufactured in England for more than 70 years. In the U.S., the Prentif received FDA approval in May,1988.

As with the diaphragm, a cervical cap requires a prescription. A woman must see a health care professional to determine the correct size and to ensure that she understands the proper insertion technique.

There are no known related health risks associated with using the cervical cap and spermicide method of birth control. Some women may find spermicides to be irritating, but changing brands may help. The cervical cap can be difficult to insert, but is handy for women who cannot use a diaphragm because of poor muscle tone. Women who suffer from recurring urinary tract infections related to diaphragm use may want to try using the cervical cap. About 4% of women will have abnormal looking cells (non-cancerous cells) on their Pap smears after using the cervical cap for 3 months.

It is important to remember that using a cervical cap does not protect from sexually transmitted infections, although spermicides may give some protection against chlamydia and gonorrhea.

When the cervical cap and spermicide are used correctly, they are more than 80% effective for birth control, essentially the same reliability as for the diaphragm. However, effectiveness is lower in women who have already delivered children.

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SOURCE: Archives of Pediatrics & Adolescent Medicine