One of the more recent studies on the effectiveness of natural family planning, conducted in Germany and published in 2007 in the journal Human Reproduction, found that the Sympto-Thermal method
results in 0.
Studies show that the sympto-thermal method
of NFP is 99 percent effective, the same as the birth control pill.
There is the Sympto-Thermal method
and then there are the two mucus-based methods; Catholic Insight featured the latter two methods in past issues.
Our involvement has been and is with Serena, a Canadian organization with over 45 years experience which teaches the Sympto-Thermal method
of fertility awareness, primarily on a couple-to-couple basis.
Two of the most common natural methods today are the Sympto-Thermal Method
and the Billings Ovulation Method.
The site has a clear but detailed overview on all the important terms and observations necessary for the various methods of NFP, as well as a methodical breakdown of each of the major NFP methods including the Calendar, Billings, and Sympto-Thermal methods