Abstract

PIP: The new methods of natural family planning, i.e., the cervical mucus and symptothermal methods, provide couples with a form of birth control which is medically safe, totally and immediately reversible, and highly effective for stronly motivated couples. Furthermore, these methods cost nothing, have no side effects, and are completely drug and device-free. These methods are totally distinct from the traditional rhythm method which requires a woman to make daily quesses about her fertility status on the basis of her previously observed menstrual cycle patterns. In contrast, the new methods allow a woman to identify with certainty her current fertility status. These innovative methods are based on recent research which indicates that women are naturally safeguarded from pregnancy during 60-70% of their reproductive lives. Women can easily be taught to recognize physical symptoms which identify the naturally fertile and infertile perods of each cycle, i.e., 1) changes in the appearance and texture of cervical mucus, and 2) changes in basal body temperature. During the fertile periods, the cervical mucus is thin, slippery, stretchy, and clear. In this state the mucus helps the sperm cells travel up through the cervix and also provides an environment that keeps sperm cells viable for up to 5 days. During infertile periods, the cervical mucus is thick and gummy and acts as a barrier to prevent sperm from traveling through the cervix. During the fertile period the vaginal opening has a sensation of wetness and slipperiness, but during the infertile period, the vaginal opening has a sensation of dryness. Changes in basal body temperature can be used to identify the 2-week, naturally infertile, postovulatory phase of the menstrual cycle. Immediately after ovulation, a woman's temperature rises by .3-.4 of a degree. A temperature rise, sustained for 3 days, indicates that ovulation has occurred and that the egg is no longer viable. Women may use either or a combination of these symptoms to identify their fertile and infertile days. These methods require couples to abstain from intercourse during the fertile period which generally lasts for 7-12 days. The use of creams, jellies, and other chemicals during the fertile period to avoid the need to abstain is not recommended because these substances may mask changes in cervical mucus. According to a 2-year Canadian study couples who used these methods for spacing purposes only had a failure rate of 14.9 pregnancies/100 woman years; however, couples who definitely wanted no moe children, had a failure rate of only 1.1 pregnancies/100 woman years. Apparently, the strength of the motivation to prevent pregnancy accounted for the marked differences in the failure rates of these 2 groups.