A sponge contraceptive is categorized as being among the barrier methods of birth control. Barrier by it's very definition brings to mind an object that keeps a different object from getting by it, denying assess to what lies on behind the initial object. This is precisely the principle upon which the sponge contraceptive works.
The sponge contraceptive is a soft disk-shaped foam device containing spermicide. It is inserted into the vagina and covers the cervix, forming a barrier keeping sperm from reaching the egg. The spermicide contained within the sponge contraceptive kills sperm as well adding to the devices abilities to prevent fertilization.
Some might think that the sponge contraceptive available on the store shelves is a form of birth control new, but it's not. It was approved for use by the Food and Drug Administration in 1983 and quickly became very, very popular. Its removal from the market twelve years later, in 1995, came about because the plant that manufactured it was found to be using contaminated water in the manufacture of its products (not just the sponge contraceptive). Unwilling to incur the expense of improving their plant to meet manufacturing standards the company pulled the device from the market.
While available outside the US this sponge contraceptive only recently (April 22, 2005) received FDA approval once again. So in a sense for most younger Americans seeking a form of barrier birth control this is a birth control new to them.
The sponge contraceptive is a reversible form of birth control. Once removed within twenty-four hours a woman, provided she is at the right point in her cycle and an egg has been released, can conceive.
The sponge contraceptive has been found to have a higher success rate in women who've never had children than those that have. Effectiveness also rates heavily on adherence to instructions. For instance, those women who have not given birth and follow the instructions for sponge contraceptive use to the letter can expect an effectiveness rate as high as 91%. Typically use drops the effectiveness rate to 84%. Basically this all revolves around the mechanics of the sponge contraceptive, in other words how well it fits on the cervix. Effectiveness rates drop for those women who have had children due to the stretching of the vagina and cervix that occurs as the baby is being born. Those who haven't gone through the rigors of childbirth can expect a tighter fit. This tighter fit means a lessened chance for sperm to get around the barrier and unite with an egg.
The sponge contraceptive is inexpensive, its effects are reversible and for those women concerned with possibly upsetting their hormonal balance, contains spermicide as opposed to the hormones found in most other contraceptive devices. It is effective immediately upon insertion and doesn't affect sexual interactions.
It's advisable to put to keep it in no longer than twenty-four hours so should be put in just prior to planned sexual activity. Following completion of said activity it is best to leave it in for six hours or so to make sure than any lingering sperm are done away with by the spermicide. There is always the outside risk of developing toxic shock syndrome (TSS) a rare but life-threatening bacterial infection if the device is left in for a lengthy period of time. The symptoms of TSS include fever, nausea, vomiting, diarrhea, muscle pain, dizziness, faintness and a sunburn like rash on the face or body.
As with using tampons it's best to be careful and aware but this doesn't mean to avoid using a potentially useful birth control tool.