Over the years, numerous substances have been tried to prevent fertilization, including ox blood, cow dung, vinegar, lemon juice, oil and honey. Serious widespread research started only in the 1930s, and in the subsequent years there were many brands available. With the advents of the pill and IUD interest waned, and there are now comparatively few brands on the market.
Spermicides combine two agents: aly inert blocking material, which physically impedes the sperms’ progress, and a second substance which ly destroys or immobilizes the sperm. Most brands are based on nonoxyno1-9, which coats and breaks down the surface of sperm cells. Spermicides come in various forms: cream, jelly, pessary, aerosol foam, foaming tablets and water-soluble film.
The exact method of use depends on the type used. Foaming tablets and melting pessaries or suppositories require three to twenty minutes to disperse, depending on the brand used. The water-soluble film can be placed in the vagina or over the tip of the penis. Jellies and creams really rely on the thrusting of the man’s penis for full distribution. Foam is used from an aerosol can; the can needs to be shaken fully to ensure that theis well mixed and aerated.
With most types a separate applicator is filled from the nozzle of the can, although some brands come pre-filled. The applicator is inserted far back into the vagina and the plunger pressed. This can be done immediately before intercourse, or up to thirty minutes previously. If you use foam it is best always to keep a spare container in the house, as there is often no warning that one is about to run out. Alls deteriorate in time, or if the container becomes damaged or the material becomes too hot or cold; so take careful note of any ‘use by’ date, and store in a dry, reasonably cool place.
Spermicides alone are one of the few methods ofavailable without any medical intervention. Spermicides are available over the counter at chemists’, and require no prescription — although they can also be obtained on prescription, and free from family planning clinics. Spermicides alone have remained a reasonably popular contraceptive alternative as they are less bulky to carry around and less complicated to use than when combined with a cap or sheath.
Spermicides act as good lubricants for sex, which can be an advantage if the woman’s membranes are fairly dry, for example during and after the menopause. There is no difficulty in re-establishing fertility when a pregnancy is wanted, and no evidence as yet of any medical risks to husband or wife. Some spermicides also offer some protection against some forms of VD – evidence suggests that they can restrict the growth of organisms causing gonorrhoea and genital herpes.
Spermicides alone need to be used at or near the time of intercourse, which can interrupt the spontaneity of lovemaking. They also inevitably increase the vaginal discharge after sex, as they add to the seminal fluid and the woman’s secretions — with a sheath or cap, either the semen or some of the spermicide is contained inside. Warm and humid climates can cause handling problems with creams and melting pessaries, as they begin to liquefy; this can be remedied by running them under cold water before use.
Although the modern spermicides are all tested chemically, some can still produce irritation in either partner. If this does happen, changing to one with a different chemical base may help. Recent research has shown that nonoxynol9 is absorbed through the vaginal mucous membranes, which has led to some concern that this could damage the woman, or a child if she is breastfeeding. This area is being researched further. Finally, there can still be some embarrassment over buying spermicides, although many large chemists’ display them for self-selection to ease this problem.
The theoretical failure rate for spermicides alone can be as low as 3 per 100 woman/years, but actual failure rate is much higher. Studies over the last fifteen years have produced failure rates of up to 29, with an average of about 20 (although the Which? Guide to Birth Control is more optimistic, and says about 10). Failures occur both when the spermicide is used, and when couples decide to take a risk and not use it. Foams are the most effective spermicides, probably because they are immediately distributed across the cervix. Foaming tablets and melting pessaries can fail to disperse properly. Jellies and creams are not intended for use on their own (they are designed for use with a cap or sheath), but because they too are on sale without prescription they are often used alone and are not as effective as other spermicides. Also, because creams and jellies are mainly distributed by penile thrusting, pregnancy can occur if the husband suffers from premature ejaculation, before the spermicide is well distributed. Soluble film is very difficult to position correctly, whether it is used by the man or the woman, and is not as effective as foam.
Don’t use spermicide alone if it is important that you don’t conceive! The failure rate is too high to take risks with. On the other hand, if it would not be too disastrous if you conceived, and you don’t like the pill and IUD and don’t want to bother with a cap, sheath or rhythm method, then spermicide alone will certainly give quite a few women a fair degree of protection against pregnancy. This method is not a wise choice for a newly-married couple, who would have to worry about the messy mechanics of using spermicide as well as about the high failure rate, but it could be a perfectly good method for a couple who have had one child and are not too bothered when the next arrives. It is also a very good back-up method for emergencies when a sheath splits; applying foam immediately can help to prevent pregnancy.
Couples are more likely to use this method conscientiously when it is for a limited time, so it can also be a good method for unprotected days before a packet of pills takes effect, or if one pill in a cycle is forgotten. However, the general consensus is that spermicides are far more effective when combined with a cap, sponge or sheath. One of the main functions of the cap and sponge is to hold the spermicide over the cervix, where it is most needed, which is difficult to achieve with spermicide alone.