Abstract
Nowadays, there is an increasing interest in natural family planning methods. The biological basis for the application of natural family planning methods is the recognition of ovulation and, more extensively, of the fertile period. Several studies in the past decade have shown the efficacy of these methods and that the main cause of failure was either a conscious departure from the rules of the method or erroneous application of the method. Another problem affecting natural family planning that has been highlighted is the relatively high discontinuation rate. These features are probably due to low compliance in applying the natural family planning rules, which may be too demanding for a number of couples. In this review, there are comments on the application of natural family planning methods, the discontinuation rates and the failure of the method due to mistakes in the studies carried out in the past 15 years. Steps that can be taken to limit mistakes and discontinuity are also addressed.