The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple’s sexual behavior during the fertile time: a prospective longitudinal study

BACKGROUND: The efficacy of fertility awareness based (FAB) methods of family planning is critically reviewed. The objective was to investigate the efficacy and the acceptability of the symptothermal method (STM), a FAB method that uses two indicators of fertility, temperature and cervical secretions observation. This paper will recommend a more suitable approach to measure the efficacy. METHODS: Since 1985, an ongoing prospective observational longitudinal cohort study has been conducted in Germany. Women are asked to submit their menstrual cycle charts that record daily basal body temperature, cervical secretion observations and sexual behaviour. A cohort of 900 women contributed 17 638 cycles that met the inclusion criteria for the effectiveness study. The overall rates of unintended pregnancies and dropout rates have been estimated with survival curves according to the Kaplan-Meier method. In order to estimate the true method effectiveness, the pregnancy rates have been calculated in relation to sexual behaviour using the 'perfect/imperfect-use' model of Trussell and Grummer-Strawn. RESULTS: After 13 cycles, 1.8 per 100 women of the cohort experienced an unintended pregnancy; 9.2 per 100 women dropped out because of dissatisfaction with the method; the pregnancy rate was 0.6 per 100 women and per 13 cycles when there was no unprotected intercourse in the fertile time. CONCLUSIONS: The STM is a highly effective family planning method, provided the appropriate guidelines are consistently adhered to

State-of-the-art of non-hormonal methods of contraception: IV. Natural family planning

Despite the popularity of ‘modern’ contraceptives, natural family planning (NFP), including fertility awareness-based (FAB) methods and withdrawal, are practised in most countries. Worldwide FAB methods and withdrawal are used, respectively, by about 3.6% and 2.9% of all couples of reproductive age. This article describes the underpinnings of the different NFP methods, their rationales, histories, rules for use, efficacy and in broad categories their prevalence. Pregnancy rates of FAB methods with perfect use have ranged between 0.3 and 5.0 per 100 users per year, but typical use rates rises into the teens or higher. Withdrawal requires the male partner to be aware of his impending climax and to pull out of the vagina before ejaculation. Perfect use and typical pregnancy rates for withdrawal are estimated to be 4 and 27 per 100 per year, respectively. Many couples find NFP in accord with their own beliefs, satisfactory in its effectiveness and useful in planning a desired pregnancy. Many prize their self-control in practising NFP or withdrawal. In our research we used Medline, Popline and the Cochrane Library search engines in English, local institutional libraries, our own files in our native languages, the literature references contained therein, and source recommendations from colleagues