Effectiveness and acceptibility of the symptothermal method of natural family planning in Germany.

Throughout Germany, 851 women who were instructed in natural family planning participated in a prospective study. Of these, 255 women with 3174 cycles used only natural family planning for family planning and 274 women with 3995 cycles occasionally used barrier methods in the fertile phase. For natural family planning--only users, the Pearl rate for unplanned pregnancy was 2.3 and for mixed-method users 2.1. Most pregnancies resulted from unprotected intercourse during the fertile phase, and the use of barrier methods does not reduce risk-taking.