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Birth Control Behavioral Methods (cont.)

Natural Family Planning

Natural Family Planning (NFP), endorsed by the Couple to Couple League, is one of the most widely used methods of fertility regulation, particularly for those whose religious or cultural beliefs do not permit devices or drugs for birth control. This method involves periodic abstinence (no sexual intercourse), with couples attempting to avoid intercourse during a woman's fertile period (the time of ovulation). Ovulation refers to the release of an egg by the ovary.)

The current method of NFP taught by the Couple to Couple League and many other teaching organizations is the symptothermal method. Women who employ this method observe the changes in their cervical mucus, their basal body temperature (i.e. temperature on awakening), and the pattern of their menstrual cycle. They may also monitor physical changes in the cervix. This method divides a woman's menstrual cycle into 3 phases. Phase I is preovulation infertility, and it begins with the first day of menstruation. Phase II is the fertile period, in which conception may occur. Phase III refers to the period following ovulation when a woman is no longer fertile. It is best used by women who have consistent and regular menstrual cycles.

  • The symptothermal method determines the first day when sexual activity should be avoided based on how many days have elapsed since the onset of menses (typically 7) or the first day when mucus is detected, whichever is noted first. The end of the fertile period (Phase II) is determined based on basal body temperature readings. The basal body temperature is relatively low during the follicular phase (first half) of the menstrual cycle, and it rises during the luteal phase of the cycle.  This temperature elevation occurs in response to the thermogenic (i.e. heat-producing) effect of progesterone, a hormone which is released from the ovary following ovulation. The temperature rise can vary from 0.2-0.5° C. The higher temperatures begin 1-2 days after ovulation and correspond to the rising level of progesterone. Intercourse can safely resume 3 days after the temperature rise.
  • To monitor cervical mucus, a woman must assess her cervical mucus with her fingers. Under the influence of estrogen, the mucus increases in quantity and becomes progressively more elastic. This is followed by scant and dry mucus because of changes induced by the influence of progesterone.  This thick, scanty mucus remains until the onset of her next menses. Intercourse is allowed 4 days following the maximal cervical mucus production, coinciding with the rise in basal body temperature.  She is then considered to be safe until the onset of her next menses.

NFP has advantages and disadvantages:

  • How effective: The American Journal of Obstetrics and Gynecology reported that "the Sympto-Thermal Method of Natural Family Planning can be used at the 99% level of effectiveness in avoiding pregnancy." If a couple takes chances and has intercourse during Phase II, the fertile period, their odds of pregnancy increase dramatically. In August, 2002, the U.S. Food and Drug Administration (FDA) reported a failure rate of 20 pregnancies per 100 women per year for periodic abstinence. This figure did not differentiate for the particular methods of periodic abstinence. The American College of Obstetricians and Gynecologists (ACOG) lists a higher failure rate for periodic abstinence of 25%. Again, this figure does not differentiate for type of periodic abstinence.
  • Advantages: No harmful effects from hormone usage occur. This may be the only method acceptable to couples for cultural or religious reasons. NFP methods can also be used to achieve pregnancy.
  • Disadvantages: This method is most suitable for women with regular and predictable menstrual cycles. Complete abstinence is necessary during the fertile period. This method requires discipline and systematic charting. The method is not effective with improper use. To employ this method effectively, a woman or couple should be trained by a medical professional or a qualified counselor. A relatively high failure rate has been reported. This method does not protect against STDs.
Medically Reviewed by a Doctor on 7/7/2016
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