Does abstinence work? Natural methods users and consistency of behavior

Ester L. Rizzi, Université Catholique de Louvain

The percentage of couples using Natural Family Planning who experiment an unintended pregnancy is around 25%. The high percentage of failures in preventing a pregnancy can depend on a misuse of the method, but also on the difficulty to respect the abstinence rule regarding the fertile days of the cycle. The aim of this paper is to assess consistency of behavior for Natural Family Planning users. A detailed typology of behaviors of ‘avoiders’, i.e. couples who try not to have intercourse in the fertile window, will be presented, together with an analysis of determinants of temporary interruption of an avoiding behavior. We will consider data on 1,074 couples and 10,508 menstrual cycles - for which acts of intercourse are recorded - coming from a Multinational Study on Daily Fecundability which involves eleven European NFP centers.