The book “Taking Charge of Your Fertility” discusses many methods for monitoring fertility. Essentially, it uses the sympto-thermal method, and includes a little bit of everything: cervical mucus, basal body temperature, cervical changes, cycle averaging, and LH monitoring. The problem with this form of NFP is confusion: it is very complex, and without formal instruction, hard to master. Often, a couple will have more days of presumed fertility with this “catch-all” method, than with some other programs, simply because of the nonspecific nature of some of the signs they are monitoring.
Cervical mucus is an indicator of approaching ovulation, and research indicates that of all the external signs of fertility, cervical mucus is most specific to the time of ovulation. Cervical softening, abdominal pain, and breast tenderness are all less accurate, nonspecific signs of ovulation. Temperature tells one when ovulation has passed, not when it is coming. The LH monitor also indicates when ovulation is approaching, however, it will miss the LH surge in about 8-10% of cycles, and misses the beginning of the fertile time in about 30% of the cycles. Therefore, it is currently only recomended for use in achieving pregnancy, not avoiding it. If a couple uses the monitor to avoid pregnancy, they must monitor another sign of fertility also, such as mucus.. All methods of NFP utilize cervical mucus monitoring, however, not all have standardized methods for observing it. Billings and Creighton methods are the most standardized mucus-only methods.
To get some formal instruction in a particular method of NFP you can consult the Professional Directory on the CANFP web site to find a teacher in your area.
Gail McNaughton, NP, FCPI