The Science behind the fam method
Glossary:
Fertile Window
The fertile window is the number of days each menstrual cycle that unprotected intercourse can lead to pregnancy. There is only one fertile window per menstrual cycle and it is always the 5 to 6 days leading up to ovulation and the 24 hours to follow. This is based on the lifespan of sperm in optimal fertile cervical fluid and the lifespan of the egg once released during ovulation. (Source)
Ovulation
Ovulation is the moment when an egg is released from the ovary. Ovulation occurs only once in each menstrual cycle. Very rarely two eggs are released, always within hours of one another, in the same ovulatory window. This is the case for fraternal twins. Ovulation is not a week-long event, but rather a momentary event when the egg ruptures free from the ovary.
Cervical Fluid
Cervical fluid, also known as cervical mucus, is a type of fluid made by the cervix that is highly influenced by the reproductive hormones estrogen and progesterone. It can be seen and felt at the opening of the vagina as well as on one’s underwear. It can range from a dry and tacky sensation, to a watery fluid, to a thick and slippery secretion. While it is a type of vaginal discharge, not all vaginal discharge is cervical fluid.
Basal Body Temperature (BBT)
Basal body temperature is one’s natural temperature after an extended period of rest. It is often measured at the same time each morning before getting out of bed. Basal body temperature is impacted by the reproductive hormone progesterone. To record one’s basal body temperature an oral fertility or ovulation thermometer that reads out to two decimal places is recommended. Forehead, ear, and other non-oral thermometers are generally not recommended for basal body temperature tracking.
Now that we’ve got the language down, let’s explore the science behind fertility awareness methods…
With the rise of cycle tracking and period apps, more and more women are getting curious about tracking their menstrual cycles as a form of birth control and pregnancy prevention. As a certified fertility awareness educator (FAM Educator) with over 13 years experience and clients in 6+ countries across 3 continents, I love this curiosity. However, I also want to make sure that those who are interested in tracking their cycles as a form of birth control are doing it correctly, understand the science behind cycle tracking methods of birth control, and are aware of the fact that cycle tracking and period apps are NOT effective forms of natural birth control.
In this article, we will explore…
What are fertility awareness methods (FAMs)?
Why there is no such thing as The Fertility Awareness Method (The FAM Method)
The sympthothermal double check method of fertility awareness - Why I choose to use & teach this FAM method
The science, research, & efficacy studies behind fertility awareness methods (FAMs)
How Planned Parenthood and medical sites inaccurately report efficacy rates for fertility awareness methods skewing them lower than is true
The difference in efficacy between abstaining or using condoms during the fertile window
The difference in efficacy between typical use & perfect use accuracy
The difference in efficacy between learning from a trained educator or self-teaching FAMs methods
What are fertility awareness methods (FAMs methods)?
Fertility Awareness Methods (FAMs) are specific methods of menstrual cycle tracking that each have their own unique set of rules that when used properly are intended to naturally and effectively prevent or achieve pregnancy based on the user’s goal. FAMs are also known as natural family planning methods, or NFPs. The term NFP often refers to FAMs when abstinence is practiced during the fertile window, while FAMs often employ the use of a barrier method like condoms during the fertile window. NFP is often the term used by the religious community, while FAMs is more often used by secular educators and users.
Fertility awareness methods prevent pregnancy by identifying the fertile window in each menstrual cycle by tracking cervical fluid, basal body temperature, cervix position, and/or hormone testing so that users can either avoid intercourse or use a barrier method during the days on which intercourse can lead to pregnancy. Despite what health class and sex ed led us to believe, we can’t actually get pregnant any time we have sex. We can only get pregnant on about six days per cycle, the 5 days leading up to ovulation and the 24 hours following ovulation. This is because sperm can live in the menstruating person’s body for up to 5 days in optimal cervical fluid and the egg once released during ovulation is viable for conception for 12 to 24 hours. This creates a 6 day fertile window. Outside of this window it is biologically, scientifically impossible to get pregnant.
You can access the research study on the timing of intercourse and the window for conception here:
Wilcox et al, 1995, Timing of Sexual Intercourse in Relation to Ovulation: Effects on the Probability of Conception. The New England Journal of Medicine, 333:1517-1521 Link: https://pubmed.ncbi.nlm.nih.gov/7477165/
It’s important to note that cycle tracking on its own is not a form of birth control. It is simply keeping track of one’s cycle signs and symptoms. In order to use cycle tracking as birth control we must learn the rules of a specific fertility awareness method. Cycle tracking without FAMs rules is just a detailed look at one’s menstrual cycle… yes, even if you use an app (you can read all about why cycle apps are NOT birth control methods here).
Why there is no such thing as The Fertility Awareness Method (The FAM Method)
Despite the fact that many people and resources reference using “The FAM Method”, there is, in fact, no such thing. There is no single fertility awareness method. Rather, there are many different fertility awareness methods that utilize different fertility tracking signs and method rules. In order to use fertility awareness methods as birth control, we must choose the fertility awareness method that best suits our individual needs.
The most common types of fertility awareness methods include:
Cervical Fluid Only Method - This FAM method uses only cervical fluid tracking and rules to prevent pregnancy. A very popular cervical fluid only method is the Billings Ovulation Method.
Temperature Only Method - This FAM method uses only basal body temperature tracking and rules to prevent pregnancy.
Symptothermal Method - This FAM method uses both cervical fluid and basal body temperature tracking and rules to prevent pregnancy. This is the method that is featured in the popular book Taking Charge of Your Fertility by Toni Weschler.
Symptohormonal Method - This FAM method uses urinary hormone testing, cervical fluid, and/or basal body temperature tracking and rules. A popular symptohormonal method is the Marquette Method.
Symptothermal Double Check Method - This FAMmethod uses both cervical fluid and basal body temperature tracking and rules to prevent pregnancy, plus cycle length data for added efficacy when opening the fertile window. Two popular symptothermal double check methods are NFPTA and Sensiplan. I am trained in NFPTA.
Each method has its own efficacy rating. In my practice I use and teach the symptothermal double check method because it has the highest perfect use efficacy rating of any fertility awareness method that I’ve seen at the time of writing this post.
VERY IMPORTANT…
You’ll notice that The Rhythm Method (aka The Calendar Method) is not on this list. This is because the rhythm method is NOT a valid fertility awareness method. It does not utilize the tracking of real-time fertility signs and symptoms, which is required in order to be a true and effective fertility awareness method. The rhythm method instead is a calculation-only method that attempts to predict the current cycle fertile window based on past cycle fertility. This does not work because you are not a robot and your fertile window may shift subtly, or even dramatically, from one cycle to the next. Simple, every day things like getting sick, poor quality sleep, elevated stress, travel, and new medications can alter the timing of ovulation and the fertile window from cycle to cycle. Therefore, assuming that you are fertile around the same time in each cycle is not an accurate or effective way to prevent pregnancy.
Why I choose to use the Symptothermal Double Check Method of fertility awareness
As a highly educated, vastly experienced certified fertility awareness educator who has personally been using fertility awareness methods since 2013 when I was just 23 years old, I choose to use and teach the symptothermal double check method. Here’s why…
The symptothermal double check method is studied to be up to 99.6% effective when learned from a trained educator and all rules are followed. And, despite what doctors and the pharmaceutical companies would like you to believe, that’s the same as the birth control pill!
Some folks come to me looking to learn how to use FAMs as natural birth control and will say to me “I want to learn YOUR method.” While I’m flattered, I did not invent this method of birth control. It has been around for a longggggg time. It has been scientifically studied and proven to be a highly effective form of birth control when used correctly and learned from a trained professional.
The symptothermal double check method is so effective because it is a double check method, unlike most other fertility awareness methods which are only single check methods. A double check method means that the method utilizes TWO fertility tracking signs to open the fertile window and TWO fertility tracking signs to close the fertile window. The STM double check method uses cervical fluid signs and shortest cycle (aka earliest ovulation) data to open the fertile window and basal body temperature and cervical fluid signs to close the fertile window. This means that each fertility sign must be double-checked against another before a determination can be made about opening or closing the fertile window, which adds an additional layer of efficacy that many other FAMs lack. For example, the cervical fluid only methods only utilize cervical fluid data to open and close the fertile window. Similarly, temperature only methods only utilize temperature data to open and close the fertile window. This leaves more room for error or misinterpretation of fertility signs.
The science behind the symptothermal double check fertility awareness method
The most robust scientific study to date on the symptothermal double check method was published in 2007 and carried out by Petra Frank-Herrmann and her colleagues. This study was conducted in Germany beginning in 1985 and followed 900 women over 17,638 menstrual cycles and required them to submit daily records of cervical fluid secretions, basal body temperature, and sexual behavior. The results showed that “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”.
This means that when there was no unprotected intercourse during the fertile window (aka a condom as used or partners abstained), less than ONE person out of 100 became pregnant. That means the method is MORE THAN 99% effective at preventing pregnancy when there is no unprotected intercourse during the fertile window.
The higher rate of 1.8 per 100 women experiencing an unintended pregnancy includes those folks who engaged in unprotected intercourse during the fertile window (which is not allowed per the method, but believe me people do it ::facepalm::)
All in all the study concluded that…
“The STM [symptothermal method] is a highly effective family planning method, provided the appropriate guidelines are consistently adhered to.”
You can access the Petra Frank-Herrmann study here:
Petra Frank-Herrmann et al, 2007, The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple's sexual behaviour during the fertile time: a prospective longitudinal study Link: https://pubmed.ncbi.nlm.nih.gov/17314078/
How to use the symptothermal double check method of fertility awareness
To truly learn how to use the symptothermal double check method with maximum efficacy, we must work closely with a trained fertility awareness educator (like myself!). However, let’s talk more broadly about who it works to use the STM method as birth control and what it entails on the day-to-day.
Here is what an actual day in my life looks like as a user of the symptothermal double check method:
Wake up: Take my temperature using my basal body thermometer, ideally around the same time each day (However, this isn’t always possible and there is a simple formula for adjusting temperatures when we wake up earlier or later than usual.)
Go to the bathroom: Notice which, if any, types of cervical fluid is present on the toilet paper after wiping. There are 6 types of cervical fluid that are present throughout the menstrual cycle.I teach all about them in my Cycle Wisdom FAMs Class.
Record my morning temperature and morning cervical fluid secretions on my Sauvage Wellness FAMs cycle tracking chart.
When I go to the bathroom throughout the day: Simply notice which types, if any, of cervical fluid are present on the toilet paper after wiping
When walking around throughout the day, notice sensations at the vagina. If a gush of wetness or slippery sensation is felt, take note.
At the end of the day, simply update my cycle tracking chart with any additional cervical fluid and/or vaginal sensations that arose.
Then, I fill in any rules for opening and/or closing the fertile window that have been met on that day.
All of this tracking takes less than 5 minutes a day to do!
And, the best part is that outside of our fertile windows (which are only about 10 days long in each cycle) we usually have very little, if any, cervical fluid or vaginal wetness to notice or track because we don’t make much cervical fluid outside of our fertile windows.
Why do doctors and medical sites like Planned Parenthood report that fertility awareness methods are as low as 77% effective at preventing pregnancy?
Websites like Planned Parenthood list FAMs as being only roughly 70% effective, which is incredibly misleading. This low efficacy rating comes from grouping all cycle tracking methods of pregnancy prevention together to create a group rating. This is misleading because it almost always includes the Rhythm Method which, as I mention above, is an outdated and ineffective method of birth control that is based on past cycle length as opposed to real-time cycle signs like true fertility awareness methods. Using past cycle data to determine one’s current fertile window is inaccurate because we are not robots and simple everyday things like illness, new medications, and stress can all hinder ovulation. In fact, the rhythm method isn’t a fertility awareness method at all. Including this ineffective method in efficacy ratings drags down the efficacy rate of other, much more effective methods.
Since we’re talking about differences in efficacy reporting, we must also address a few important distinctions that impact the efficacy of fertility awareness methods (and all methods of birth control)...
Do I really need to use a condom during the fertile window with fertility awareness methods?
There is only ONE acceptable situation for not using a condom during the fertile window. That is when you and your partner choose to ABSTAIN from penis-in-vagina intercourse. That is the only acceptable time! ONLY. Am I clear, y’all?!
Otherwise, YES, you absolutely always need to use a condom during the fertile window if you are using fertility awareness methods to prevent pregnancy. When we choose to have penetrative intercourse during the fertile window we are choosing to default to a barrier method as our form of birth control. This is because your chosen fertility awareness method has identified for you that this is the time when you are capable of becoming pregnant. The fertility awareness method cannot prevent a pregnancy when intercourse is had during the fertile window, rather it identifies for you that you are IN your fertile window. Given that this is the time in most of our cycles when we feel the most interested in sexual activities and our libidos tend to be the highest, many of us FAM users (myself included) choose to have intercourse during our fertile windows. We rely on condoms as our birth control method for any intercourse within the fertile window. Therefore, an important part of learning to use FAMs as birth control is learning to use condoms effectively.
The difference in efficacy between abstaining or using condoms during the fertile window when using the symptothermal double check method for pregnancy prevention as determined by the Petra Frank-Herrmann study mentioned above is…
Negligible.
In fact, using condoms WITH the symptothermal method provided increased efficacy than relying on condoms alone as pregnancy prevention. How could this be?
Likely because FAMs users are far more committed to using a condom on designated fertile window days since they know they are definitely fertile at that time and are not fatigued from having to use condoms every single time that they have intercourse.
What is the difference between typical use and perfect use efficacy for birth control?
When we talk about efficacy rates for birth control methods, it is important to discuss the difference between perfect use rates and typical use rates. Perfect use rates refers to how well a method prevents pregnancy when it is used perfectly every time. FAMs, the pill, the IUD, and most other popular birth control methods have high perfect use rates all above 99%. Typical use rates refers to how well a method prevents pregnancy when accounting for the typical daily usage, user negligence, and user error. Implanted birth control methods like the IUD and the arm implant have high typical use rates because there is little room for human negligence or error with a device that is medically inserted into one’s body. However, I have had a handful of clients who have had unplanned pregnancies while on the hormonal IUD due to the device shifting or being improperly implanted. Hormonal birth control methods like the pill and the vaginal ring have slightly lower typical use rates because there is more room for human error such as forgetting to take one’s pill or forgetting to remove or reinsert one’s ring. Barrier methods, like condoms, have a high perfect use rate, but a lower typical use rate because there is even more room for human negligence (ie. choosing not to use a condom) and human error (ie. putting the condom on incorrectly, using an old condom, or using a condom that is too small). Fertility awareness methods have a bad rap for having lower than normal typical use rates because the margin for human negligence and error is thought to be much higher than hormonal and barrier birth control methods. Here’s why, as a highly experienced FAM Educator, I don’t agree with that assumption…
Self-teaching fertility awareness methods as birth control versus learning from a trained FAM Educator yields very different results. At best self-teaching involves learning from an in-depth, comprehensive learning manual like Sensiplan or Taking Charge of Your Fertility, though neither of these manuals comes with the ability to do a wide variety of practice charts or direct access to a trained FAMs Educator which I find crucial to being able to effectively learn how to use FAMs as birth control.
At worst self-teaching involves some combination of learning from blog posts, podcasts, ChatGPT, and cycle tracking apps. This is a truly terrible way to learn how to use FAMs for pregnancy prevention. There is no concise way to know if you are learning a specific fertility awareness method or which FAMs rules you are learning and applying and if they are all part of the same FAMs method. In addition, cycle tracking apps(as I’ve shared one million times) are not approved for fertility awareness method tracking and are not effective forms of birth control.
While we do not have specific efficacy rates on self-teaching fertility awareness methods at this time, it is safe to assume that they are much lower than the efficacy rates of learning how to use fertility awareness methods from a trained FAM Educator.
When you choose to learn how to use fertility awareness methods as birth control from a trained, respected FAMs Educator, the difference between perfect use and typical use is often much more similar, in my professional opinion, to conventional birth control methods. While there is room for human negligence, many of us wouldn’t dare choose to engage in unprotected intercourse during our fertile windows when we are so obviously able to identify that we are inside of the window. And while there is room for human error because there is not a hormone-emitting device medically inserted into our bodies, when we learn from a trained FAM Educator, do the required practice charts, seek out the support of our FAM Educators to open and close our fertile windows, and ask questions whenever they arise, the window for human error is also quite small (again, in my professional opinion).
This all leads me to the very impressive statistic that I carry as a highly experienced FAM Educator here at Sauvage Wellness, and that is that…
ZERO of my clients have had an unintended pregnancy after working with me to learn how to use FAMs as natural birth control.
ZERO clients.
Over 10 years.
Across 6+ countries and 3 continents.
From age 19 to 40+.
From college to postpartum to perimenopause.
Women with PCOS.
Women with irregular cycles.
Women with little cervical fluid.
Women with wonky sleep schedules for tracking their temps.
Mothers of babies & toddlers.
Nurses.
Construction engineers.
Acupuncturists.
Students.
Teachers.
Women of all ages, races, nationalities, professions, and cycle histories.
ZERO UNINTENDED PREGNANCIES.
(And several were even so excited about fertility awareness methods that they went on to become FAM Educators themselves - special shoutouts to Erin & Karmen!)
So, that’s a pretty big deal.
The difference between learning from a FAM educator and self-teaching the fam method
So this brings me to a question that comes up a lot… “Do I really need a FAMs Educator to use fertility awareness methods as birth control when so much information is available on the internet, ChatGPT knows everything, and cycle tracking apps are so easy to access?”
And, the answer is a resounding Y-E-S!
All of the scientific efficacy data on the symptothermal double check method, as well as other FAMs methods, is based on working closely with a highly trained educator. It is based on learning a specific FAMs method, all of its rules, and having close contact and charting practice with a highly trained educator.
Choosing to learn FAMs from the internet, ChatGPT, and cycle tracking apps is risky. It’s not something that we have any efficacy data on. It’s also something that I can tell you has caused unplanned pregnancies in many folks I have come across in my time as a FAM Educator.
Choosing to learn FAMs from the internet, ChatGPT, and cycle tracking apps is like deciding to shove an IUD into your cervix all by yourself at home. You don’t know what you’re doing. You don’t know what to expect. You don’t have any practice. And, there is a lot of room for f*cking things up.
So, if you’re interested in learning how to use FAMs as birth control, please work with a FAMs Educator.
Here is a really simple, inexpensive way you can learn FAMs from me…
Join me for one of my monthly Cycle Wisdom FAMs Classes.
It is a 3 hour class in which I will teach you the entire FAMs method and demo practice charts with you. Following class you will have the opportunity to join my Monthly FAMs Support Membership (it’s only $49/mo) where you will be able to ask me questions 24/7, get unlimited chart reviews from me, access my comprehensive practice chart library, dive into my FAMs masterclass training vault, and more. It’s how to get my hands-on, expert-level FAMs support with each and every chart as you’re first starting out (or anywhere in your FAMs tracking journey!).
