With natural family planning (NFP; or the symptothermal method), a woman charts her menstrual periods by taking a daily basal body temperature (BBT) and checking cervical mucus to determine when she ovulates. During ovulation, she abstains from sex­ual intercourse. Although this may also be referred to as the rhythm method, generally the rhythm method does not involve monitoring the signs of ovulation.

Подпись:Подпись:When charting is used in conjunction with another form of birth control such as condoms, it is referred to as fertility awareness. In 2002, CycleBeads began a media campaign in hopes of increasing women’s interest in natural family planning. CycleBeads are a series of color-coded beads that enable a woman to keep track of her menstrual cycle and avoid sexual intercourse on fertile days. To avoid pregnancy dur­ing that time, the woman and her partner would abstain from sex or use a different method of birth control.

Подпись: Darin DerstineNatural Family Planning and Fertility AwarenessПодпись: To use CycleBeads, a woman moves a ring over a series of color-coded beads that represent her fertile and low-fertility days. The color of the beads lets her know whether she is on a day when she is likely to be fertile.Подпись:How They Work

With natural family planning, a woman takes her BBT every morning before she gets out of bed and records it on a basal body temperature chart. Changes in hormonal levels cause body temperature to rise 0.4° to 0.8°F (0.2 to 0.4°C) immediately before ovulation, and it remains elevated until menstruation be­gins. A woman using this method monitors her cervical mucus, which be­comes thin and stretchy during ovulation to help transport sperm. At other times of the month, cervical mucus is thicker. After 6 months of consistent charting, a woman will be able to estimate the approximate time of ovula­tion, and she can then either abstain from sexual intercourse or use contra­ception during her high-risk times (usually this period is between 1 and 2 weeks). Most women who use this method are spacing their pregnancies and are not as concerned about preventing pregnancies.

The rhythm method involves abstaining from intercourse midcycle, when ovulation is probable, but usually does not include BBT or cervical mucus chart­ing. Ovulation kits, available in drugstores, can help women who desire preg­nancy to determine their fertile days. Researchers at Duke University are work­ing on a “hydration detection” device that would allow a woman to monitor the water content of her cervical secretions through a small vaginal probe (Jennings, Arevalo, & Kowal, 2004). Increases in cervical secretions would indicate possible ovulation, and a woman using this method would avoid intercourse or use contraception.