Scientific basis and efficacy
Fertility awareness based methods (FABMs) involve charting the menstrual cycle by tracking physical signs or biomarkers that provide information about the fertile and infertile phases of the cycle. This information allows the users of FABMs to alter their sexual behavior to avoid or achieve pregnancy. Correct and consistent use of a fertility awareness based method can be as effective in preventing pregnancy as other modern methods of contraception. A research-informed method coupled with professional instruction and personal commitment can provide an effective form of contraception for those for whom a FABM is good fit.
The Justisse Method
The Justisse Method is a symptothermal FABM combining cervical mucus and basal body temperature charting. Cervical changes can be charted as an optional third biomarker. The Justisse Method also has guidelines for mucus-only charting which means that it can be used as a mucus-only method. The Justisse methodology strives to increase body literacy and users are encouraged to observe other signs such as ovulatory pain, breast tenderness, fluid retention, changes in appetite, and emotional sensitivity to monitor hormonal processes and well-being. This level of body literacy supports making informed decisions with respect to health and judging the likelihood of conception from having intercourse, day by day.
Available Research
A systematic review from 2018 (Peragallo Urrutia et al.) indicated a lack of high-quality studies on the effectiveness of FABMs. Likely reasons for this include:
General lack of funding for these methods
A low number of users
The challenge of studying FABMs in a comparable way to other methods
Although studies indicate perfect-use efficacy rates between 95.2 and 99.6 % for modern FABMs (Peragallo-Urrutia et al., 2018), these methods are highly user-dependent and typical-use rates are harder to define. Typical use effectiveness rates have ranged between 77.2 and 98.2 % depending on the method and study population (Trussel et al., 2018; Peragallo-Urrutia et al., 2018) but because of the marginal nature of these methods, population level typical-use rates comparable to those obtained for more widely used methods are not available for individual FABMs. The only population level rate available indicated a typical-use rate of 76 % for users of any method based on identification of fertile time with the majority using a calendar based method or merely attempting to time intercourse based on their own (correct or incorrect) understanding of their fertile period (Jennings & Polis, 2018; Turner, 2022 ).
Efficacy
FABMs can be highly effective methods with perfect-use rates comparable to other modern methods of contraception , including hormonal contraceptives. However, motivation, consistency, partner support, behavior during the fertile phase, and access to professional instruction may significantly influence the effectiveness an individual can experience.
All methods of contraception have a spectrum of efficacy that spans between perfect and typical use. Perfect use refers to an efficacy rate based on the method being used exactly as it is designed. Typical use refers to an effectiveness rate under typical, real life conditions.
Justisse Method Efficacy
There are yet no independent studies on the effectiveness of the Justisse Method in particular. Studies on symptothermal methods have indicated perfect-use rates between 97.6 and 99.6 % and typical-use rates between 86.8 and 98.2 % (Peragallo Urrutia et al., 2018, Duane et al., 2022). Studies on mucus-only methods have reported perfect-use efficacy rates between 96.6 and 98.9 % and typical use rates between 77.2 and 96 % (Peragallo Urrutia et al., 2018, Duane et al., 2022). The effectiveness of the Justisse method is expected to fall within these ranges.
Symptothermal charters can expect a somewhat higher efficacy than mucus-only charters, and those learning the method with an instructor and highly motivated to use the method correctly and consistently can expect higher effectiveness than those with a more relaxed approach to possible pregnancy. The Justisse Method has been used successfully for pregnancy prevention by thousands of women since its development in the 1980s and updates to the methodology have been made to further improve efficacy as new research in the field has been published.
Recommendations
The Justisse Method is designed to be learned with the support of a licensed Justisse Method Instructor. To achieve the highest effectiveness, adhering to the recommended follow-up schedule is advised. What ensures the efficacy of the Justisse Method is proper instruction, correct and consistent use, adherence to the guidelines designed to avoid pregnancy, and asking for support when menstrual cycle parameters or intentions with the method change. Moreover, before relying on the Justisse Method as the sole method of birth control, it is recommended that the learning guidelines are first strictly adhered to for at least 3 complete menstrual cycles. Experience shows that the more consistently users follow the method as instructed, the sooner they develop confidence in the method, and the more effectively they achieve their intentions.
references
Duane, M., Stanford, J. B., Porucznik, C. A., & Vigil, P. (2022). Fertility Awareness-Based Methods for Women’s Health and Family Planning. Frontiers in medicine, 9, 858977. https://doi.org/10.3389/fmed.2022.858977
Peragallo Urrutia, R., Polis, C. B., Jensen, E. T., Greene, M. E., Kennedy, E., & Stanford, J. B. (2018). Effectiveness of Fertility Awareness-Based Methods for Pregnancy Prevention: A Systematic Review. Obstetrics and gynecology, 132(3), 591–604. https://doi.org/10.1097/AOG.0000000000002784.
Turner, J. (2020). Misrepresentation of contraceptive effectiveness rates for fertility awareness methods of family planning. Journal of Obstetrics and Gynaecology Research, 47(7), 1–7. https://doi.org/10.1111/jog.14593