Updated: Mar 31
Did you know that there are actually many different Fertility Awareness-Based Methods?
When I say "FAM" I am generally referring to the symptothermal method, popularized by Toni Weschler's book Taking Charge of Your Fertility, a method that uses cervical fluid and cervix changes (sympto), and basal body temperature (thermal).
However, TCOYF is not the only symptothermal method! There are a few different methods, most of which have studies to back them (unlike TCOYF, which we can only estimate to be about 98% effective with perfect use).
What I teach here at Cycle Wise is a single-check symptothermal method that uses evidence-based temperature rules established by Sensiplan, and cervical fluid protocols that draw from both TCOYF and my training institute, The Well School of Body Literacy. I give my students the option to incorporate a calculation rule that makes the practice more conservative (aka, a double-check method).
Single-check vs double-check methods
When it comes to symptothermal methods, there are two important distinctions: single-check and double-check methods.
A single-check method is one that relies ONLY on cervical fluid to open the fertile window. A double check method is one that relies on a calculation rule OR cervical fluid to open the fertile window, whichever comes first.
For example, Sensiplan - a symptothermal method based out of Germany that currently holds the highest efficacy rates - uses a calculation rule called Doering Day, which makes it a double-check method (I teach this rule to my students as an option).
Sensiplan carried out a 20-year study of 900 women totaling 17,638 cycles of data, revealing perfect use of 99.4% and typical use of 98.2%. Such high effectiveness is exciting, especially in a world that frequently assumes that FAM is unreliable as a contraceptive method.
However, it is important to remember that this study does not speak for all symptothermal methods (nor for all Fertility Awareness Based-Methods). It has specific protocols, rules, and instruction that are not identical to what I teach, to what TCOYF teaches, or any other method.
When using this rule, your fertile window begins either on your Doering Day or your Point of Change (first appearance of cervical fluid), whichever comes first. When not using this rule and using cervical fluid alone to determine the opening of the fertile window, the effectiveness is estimated to be around 98%. Using Doering Day to open the fertile window makes the practice more conservative but may give you less safe days before ovulation. On the other hand, using cervical fluid alone to open the fertile window is slightly less conservative but may give you more safe days before ovulation.
Efficacy of single-check methods
Simply put, we don't have great data for single-check methods. This goes for the method that I teach as well. A 2018 systematic review by Drs. Chelsea Polis and Rachel Urrutia has this to say about the efficacy of single-check symptothermal methods:
Among seven studies investigating single-check symptothermal methods, we ranked four low quality and three moderate quality. Only one study reported a first-year typical use pregnancy probability of 13.2. Among experienced users in Europe, typical use effectiveness estimates were 17.6 and 8.5. Correctly calculated perfect use pregnancy probabilities were unavailable.
In short, efficacy for typical use (how well the method worked with human error) was 82.4 - 91.5%. This means that about 82 - 91 out of 100 couples avoided pregnancy even with mistakes.
Specifics of the method that I teach
Here is a quick overview of the rules and protocols that I teach:
I teach a single-check method but I give my students the option of using Doering Day if they wish. This likely increases effectiveness, but to what degree is not known.
First 5 days of the cycle are always safe (with caveats)
Safe days after menstruation ends are available the evening of each day where only "baseline" has been observed (I use this term instead of "dry days")
The "point of change" (first appearance of cervical fluid) opens the fertile window, or, optionally, Doering Day may be used once the student has a record of 12 temperature shifts.
Safe days after ovulation begin when Peak + 3 and the temp count of 3 have been completed, on the evening of whichever comes last.
I teach Peak + 3 instead of Peak + 4 (TCOYF). Therefore, the evening of the 3rd day after Peak is considered safe (as long as the temp count of 3 has also occurred!) Statistically speaking, ovulation will occur 3 days before or 3 days after Peak Day. By waiting until the evening of the 3rd day past Peak, it ensures that any egg or eggs that were released have died (seeing that each egg has a maximum lifespan of 24 hours, and a second egg will always be released within 24 hours of the first).
Temp count of 3: the evening of the 3rd high temp is safe. This is what is taught in TCOYF and Sensiplan. However, the way my method qualifies a temp shift is based on Sensiplan temp protocols because they are more straight forward (no raised coverline), and also more accurate for using Doering Day rule.
Factors that lead to high efficacy in FAM use:
Checking and charting your signs consistently (read: almost every day)
Learning the method with a certified instructor
Receiving follow-up support from your teacher
Following all rules and protocols without cutting corners, taking risks, guessing, or assuming you're safe
When the method is easy for you! Anything that is hard or burdensome for you will make it harder to commit to following the practice correctly (and that is totally fine; FAM is not the best method for everyone!)
FAM = as effective as you want it to be
The beauty of FAM is that it allows you to be flexible with how strictly you want to avoid pregnancy. You get to decide how and if and when to bend the rules.
In this way, FAM is more like a contraceptive strategy than a method. It is fluid, customizable, and autonomous. This is much different than the implant or IUD, which sit in your body year after year, and don't allow you to altar how you use them, or a Pill dose, which is usually the same day after day. You can decide what's best for you based on your unique situation.
Although I've just talked all about effectiveness, the truth is that not everyone is trying to prevent pregnancy 100% of the time.
The desire to conceive or avoid is one that is extremely fluid.
You might be newly married and wanting to avoid pregnancy for 1 year, or you might find yourself with a new partner who gives you baby fever BAD (that's what happened to me! It really blurred some of the strictness I previously felt about preventing pregnancy).
I give each of my students a copy of The Intention Scale, which is a document that outlines how seriously they and their partner wish to prevent pregnancy at this time on a scale of 1 - 10.
I also encourage them to think about what they would like to create or nurture in their lives that will help inform and strengthen this intention. Do they want to travel the country in a camper van? Do they absolutely love teaching dance? Do they want to save their energy for these passions and hobbies instead of bringing in a baby?
I work closely with each of my students to help them utilize the rules of the method in whatever way works best for them. In this way, my practice can rest solidly on the science of fertility signs that we've had for the last 150+ years; on certain protocols adopted from the highly effective Sensiplan; and on the uniqueness of the individual I'm teaching who knows their body and life best.
Evidence based yet woman-centered: this is something hormonal methods and devices cannot claim to do, and it's what I absolutely love about teaching FAM!
I teach a single-check symptothermal method with the option to make the practice more conservative via a calculation rule. This method is based on rules and protocols taught by my training institution, The Well; on certain terms and protocols found in Taking Charge of Your Fertility; and on certain rules developed by Sensiplan. The effectiveness of this method is unknown, though can be estimated to fall somewhere between 98 - 99% with correct use. Because not everyone is trying to prevent pregnancy 100% of the time, I help my students decide how they will use the method according to their intentions.