“Natural” family planning

Natural family planning or fertility awareness aims to avoid conception by abstention from intercourse during the woman’s fertile period. It makes use of a calendar and some indicator of ovulation (basal body temperature measurements, cervical mucus characteristics or commercial ovulation prediction kits). Intercourse is avoided during the so-called fertile period at ovulation and for several days before and after. Natural family planning requires a highly motivated couple, regular menstrual cycles and the willingness to tolerate a failure rate of up to 25%. The method has no medical side effects and is accepted by virtually all religions.

Barrier methods

There are three general categories of barrier contraception: condom, diaphragm and cervical cap. All work by preventing spermatozoa from entering the woman’s uterus and fertilizing an egg. Barrier methods are good choices for individuals who want to limit contraceptive efficacy to a particular sexual episode. They are readily reversible and can be used in conjunction with the timing methods associated with natural family planning. The most serious side effects of barrier methods occur in individuals with an unknown latex allergy.

Condoms that fit over the penis are more widely available than condoms that fit inside the vagina (the female condom). Male condoms may be made from latex rubber, polyurethane or animal intestines; each provides a different “feel” or sensitivity for the man during intercourse. Female condoms are typically made of polyurethane. Intact condoms stop sperm and infectious agents from entering the vagina and so can prevent transmission of HIV and other sexually transmitted diseases. They must be carefully removed after ejaculation to avoid spilling semen from the condom into the vagina. The failure rates of condoms are 3–6% with perfect use and 15% with typical use.

The diaphragm is a soft latex or plastic dome that fits inside the vagina and covers the cervix. Because some sperm may be able to bypass the diaphragm and gain access to the uterus, spermicide is placed in the dome of the diaphragm. Diaphragms are individually fitted by a clinician and require some training for proper insertion and removal. A diaphragm should be left in place for 6–8 h after intercourse, and additional spermicide placed into the vagina if more episodes of intercourse occur before it is removed. Diaphragms partially protect against HIV and other sexually transmitted diseases. Some women develop bladder or vaginal infections during diaphragm use. The failure rate of a properly fitted diaphragm with perfect use is about 6%; it rises to 15% with typical use.

Cervical caps are similar to, but smaller than, the diaphragm. They are individually fitted to tightly cover the cervix. Failure rates are similar to those of the diaphragm. Cervical caps are not widely available.

Spermicides

These are chemicals that kill sperm by disrupting their outer cell membranes. The most commonly used are nonoxynol-9 and octoxynol-9. Spermicides are available suspended in one of three vehicles: foam, jelly or wax suppositories. Spermacides are recommended for use with a barrier method, because the failure rate of spermicide used alone is up to 30%. There are few absolute contraindications to their use. They have an unpleasant taste and can cause an allergy in some users. Spermicide use may cause inflammation of the female genital tract and has been associated with an increase in the transmission of sexually transmitted infections, including HIV.