People ask: is the symptothermal method really science based? The short answer is yes. Modern Fertility Awareness is built on measurable body signs, tested rules, and peer-reviewed studies. Below you will find what the Sympto-Thermal Method (STM) is, how it works, and how effective it is according to published researches and WHO.
“Fertility awareness-based methods” (FABM) are family planning methods that identify the fertile window using observable signs. Couples then adjust sexual behavior to achieve or avoid pregnancy (Frank-Herrmann et al., 2007). FABM include temperature-only, mucus-only, symptothermal, and sympto-hormonal approaches (Manhart et al., 2013).
The STM combines at least two daily observations: cervical mucus and basal body temperature; many programs also teach an optional cervix check. Using two independent signs adds a built-in cross-check to mark the start and the end of the fertile window (Frank-Herrmann et al., 2007). Here at Hormone Focus we do teach and recommend to observe all 3 fertility signs (Basal Body Temperature, Cervical Mucus and Cervix Position), but it is a personal decision to cross check with all three, or just with mucus + temperature sign.
In a large German cohort, STM teaching used clear rules that were tested over time:
With being able to identify the First fertile day we know when the fertility window is open. With cross-checking the sign and using strict rules we are able to safely identify the Last fertile day, that closes our fertility window. This is how we know safely when we are fertile, and when not anymore, in real time, and based on our individual body, not on any calendar or math exercise.
Peer-reviewed data show high effectiveness when rules are followed. In the Heidelberg cohort (900 women; 17,638 cycles), the pregnancy rate with correct use was 0.6 per 100 women over 13 cycles; overall unintended pregnancies were 1.8 per 100 women after 13 cycles (Frank-Herrmann et al., 2007). A 2013 clinical review concluded that modern FABM, when correctly used, have unintended pregnancy rates under 5 per 100 women-years (Manhart et al., 2013). The World Health Organization lists the sympto-thermal method with fewer than 1 pregnancy per 100 women per year with consistent and correct use, and about 2 per 100 with common use (WHO, 2023).
And here we need to state that: WHO lists the Sympto-Thermal Method (STM) a safe way of contraception, WHEN IT IS USED CORRECTLY. It means that you learn from certified educators. At Hormone Focus we also suggest to join to the Seasonal Group Course, where you not just learn independently the method, but we are peer supporting each-other and personally evaluating your learnings and charts during the 3 months learning period. In this way we make sure of that you learn the method well, so you can safely rely on it.
Modern studies avoid older biases by:
The fertile window is short (about six days). Rising estrogen produces fertile-type cervical mucus that supports sperm; the post-ovulation progesterone thickens mucus and raises basal temperature (Manhart et al., 2013). These hormone-driven shifts explain why mucus and temperature, taken together, outline the fertile and infertile phases in real time (Manhart et al., 2013). Mucus-only systems (for example, the Billings Ovulation Method) teach a similar biology for mucus changes across the cycle (FACTS Billings overview).
It is daily observation of specific signs with clear rules, not app prediction or a calendar guess (Frank-Herrmann et al., 2007; Manhart et al., 2013). We rely on the real time hormonal signals of our body, what makes this method personal, meanwhile scientifically proven.
It is adaptable to different life stages (post-pill, postpartum, perimenopause) within structured programs (Manhart et al., 2013). We can use STM to monitor our hormonal rollercoaster after coming off from the pill, therefore we know when do we need to seek support if our cycles does not get better by time. We can use an STM based method called Lactational Amennorrhea Method (LAM) for safe and hormonal free contraception during breastfeeding. Or we can monitor our hormonal shifts at perimenopause times, so we understand changes and we understand when to seek support (it is not just about hot flushes, from osteoporosis to breast cancer we have pitfalls here).
Because STM reads our body´s "today’s signs", couples can time intercourse to achieve pregnancy or avoid it with non-fertile timing or other non-hormonal way of contraception. Charts also give a simple record to discuss with a professional if something seems off (Manhart et al., 2013; Frank-Herrmann et al., 2007).
The double check symptothermal method is a scientific, rules-based system. Its effectiveness is documented in cohort studies and summarized by international bodies. If you learn the rules and apply them with care and conseqently, the data show you can trust the method (Frank-Herrmann et al., 2007; WHO, 2023).
No. STM reads real signs (mucus, temperature, cervix) each day; calendar methods predict from past cycle lengths (Manhart et al., 2013). STM is a way to read your body, calendar method is a guesswork.
Many programs teach cervix as an optional third sign. The core “double check” uses mucus and temperature (Frank-Herrmann et al., 2007). We at Hormone Focus suggest to include the cervix sign, but it is an individual decision to include in the end.
WHO shows fewer than 1 pregnancy per 100 women per year with consistent, correct use; about 2 per 100 with common use (WHO, 2023). It means that sympto-thermal method is 99% safe as a contracetion. Important to state that too: the only 100% safe way of contraception is absence of intercourse.
Frank-Herrmann, P., Heil, J., Gnoth, C., et al. (2007). The effectiveness of a fertility awareness-based method to avoid pregnancy in relation to sexual behaviour during the fertile time. Human Reproduction, 22(5), 1310–1319. https://sympto.org/data/Hum._Reprod.-2007-Frank-Herrmann-1310-9.pdf sympto.org
Manhart, M. D., Duane, M., Lind, A., Sinai, I., & Golden-Tevald, J. (2013). Fertility awareness-based methods of family planning: A review of effectiveness for avoiding pregnancy using SORT. Osteopathic Family Physician, 5(1), 2–8. https://www.sympto.org/data/Fertility_awareness-based_methods_of_family_planning_2013.pdf sympto.org
World Health Organization. (2023). Mechanisms of action and effectiveness of contraceptive methods (effectiveness table). https://cdn.who.int/media/docs/default-source/reproductive-health/contraception-family-planning/mechanisms-of-action-and-effectiveness-of-contraception-methods.pdf?sfvrsn=e39a69c2_1 WHO+1
FACTS—Fertility Appreciation Collaborative to Teach the Science. Billings Ovulation Method® overview. https://www.factsaboutfertility.org/wp-content/uploads/2017/12/BillingsPEH_REV3.pdf Facts About Fertility+1
Vollman, R. F. (1979). Wilhelm Hillebrand, First Teacher of the Sympto-Thermic Method. International Review of Natural Family Planning, 3(4). https://www.usccb.org/resources/intl%20review%20nfp-1979-vollman-first%20teacher.pdf
