RHYTHM METHODS OF CONTRACEPTION: THE OVULATION METHOD
The ovulation method, also known as the Billings method, depends on changes in cervical mucus to indicate the probable days of fertility during the menstrual cycle. The start of the fertile time is signaled by the appearance of a mucus discharge within the vagina which is whitish or cloudy and of tacky consistency. A day or two before ovulation, greater amounts of mucus are produced in a clear and runnier form with a stretchy consistency very similar to egg white. Intercourse is thought to be "safe" four days after the clear mucus begins, when the mucus has returned to a cloudy color.
The overall effectiveness of the rhythm methods leaves a great deal to be desired. The calendar method is unquestionably the least reliable among this group (failure rates are approximately 15 to 45 per 100 woman-years), and unless the woman's cycle is very regular, long periods of abstinence from intercourse will be required. Temperature methods are inaccurate because they are difficult to interpret, and in about 20 percent of ovulatory cycles, the BBT chart does not indicate ovulation. The World Health Organization found in 1978 that the ovulation method was "relatively ineffective for preventing pregnancy" based on carefully designed studies done in five different countries, with an overall failure rate of 19-4 per 100 woman-years. This is probably because many women have difficulty noting the cyclic changes in their cervical mucus, and women who have a vaginal infection (which may itself create a discharge) usually cannot use this method. In a more recent study of 725 women, an overall failure rate of 22.3 per 100 woman-years was noted.
Most couples using the rhythm methods do not experience major sexual difficulties. However, some couples may develop sexual problems because the need for abstinence creates unusual pressures to have intercourse on "safe" days regardless of whether they feel like it or not. Fear of pregnancy may also lead to sexual difficulties.
Men's Health Erectyle Dysfunction