The difference between Natural Family Planning and the calendar method? Science.

One of the biggest obstacles to people choosing to use a Fertility Awareness Method (FAM) as their primary method of birth control is the widely held misconception (pardon the pun) that it is the same as the rhythm method. People are rightfully wary of this approach since many of us (myself included) were conceived on this method, which only has a 75% efficacy in typical use. This means of 100 people using this method for one year, 25 will get pregnant. 

The rhythm method and FAM are very different approaches to birth control. To fully grasp how different they are requires an understanding of the underlying assumptions and science behind each.

The rhythm method is what we in the field call a retrospective method. It assumes that past cycles or typical cycles are a good predictor of future cycles, which sadly, they are not. By assessing when a person is usually fertile, or when the general population is usually fertile, the method attempts to predict future fertile times. Couples can then choose to abstain from vaginal intercourse during that anticipated time of pregnancy possibility.

Unfortunately, past events only provide a very rough prediction of what may happen in the future. Just like knowing what the weather did a year ago might give you an idea of what to expect today, it is only an approximation at best. Nature has major fluctuations based on all sorts of variables, so if we really want to know how to prepare for the weather, our best bet is to actually step outside. Our fertility cycles are no different.

When it comes to our cycles I have found the clockwork 28-day cycle to be the exception, not the norm.

Our bodies naturally postpone ovulation whenever we are sick, stressed or travelling, which is one major reason that predictive methods like the rhythm method don't work well. To add to this, environmental endocrine-disruptors, past hormonal contraceptive use, and poor diets all contribute to hormonal disregulation which render our cycles unpredictable. The result is that predictive methods are very often wrong.

Fortunately, FAM does not rely on past data to predict future fertility.

Instead, it relies on direct observation of our body’s scientific signs of fertility – cervical mucus, BBT and cervical position, in order to make an accurate determination of whether or not we are fertile on a given day. Armed with that information we can then choose to abstain from vaginal penetration on days that could lead to pregnancy. Or, if we are comfortable taking some risk we can choose to double up on other forms of birth control like condoms and withdrawal.

Research shows that unlike the rhythm method, FAM is 99.4% effective when implemented correctly.

Unfortunately the myth that the rhythm method and FAM are synonymous continues to be perpetuated in the media, such as a recent Bustle article that referred to "Fertility Awareness, aka The Rhythm Method." What is perhaps more alarming is the number of medical doctors who use the terms interchangeably and actively discourage their patients from using Fertility Awareness. We have experienced anecdotal evidence of this since we began offering FAM programs at Red Tent Sisters where clients report being shamed by their doctors ("good luck with that" was the response one person received when they shared their contraceptive method of choice). However, a recent survey of 297 women revealed that unfortunately our clients are not alone. 

9% of women have been laughed at by their doctor when sharing they use Fertility Awareness Based Methods (FABMs) to plan their family.

27% of participants also shared that their doctor equated (FABMs) with the rhythm method. This survey reflects findings reported in the Journal of the American Board of Family Medicine:

"When provided with positive information about FABMs more than 1 in 5 women in the United States expressed interest in using one of these methods to avoid pregnancy. However, only 1% to 3% percent of US women are currently using an FABM for this purpose."

We firmly believe there is no "perfect" method of contraception - each come with their own benefits and challenges. However, the discrepancy highlighted above indicates how many people are not given the opportunity to make an informed choice and instead, are pressured into contraceptive methods that may not be aligned with their values.  

Another reason why the rhythm method is getting confused with FAM recently is due to period prediction apps, which to the lay person can easily be confused with FAM apps. It is important to note that some apps are based on retrospective prediction, while others are purely based on FAM techniques (like Kindara). Some combine both features and thus contribute to the confusion.

FAM is a skill that improves with time and quality education.

Therefore, if you are looking for effective birth control you’ll want to invest time, money and energy in the same way you would any other skill. The benefits are worth it. Not only will you be able to effectively manage your birth control independently and without hormones, but there are emotional, energetic and spiritual benefits to FAM that go far beyond fertility management. 

We're grateful to members of our community who have already taken the time to correct misinformation like that on the recent Bustle article. We'd love your help in continuing to spread the word about the difference between FAM and the rhythm method so we can establish a culture of accurate, informed consent when it comes to contraceptive options.

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Kim & Amy Sedgwick love to discuss sex, periods, and all the other things we’re not supposed to talk about. The co-founders of Red Tent Sisters, they’ve been featured in every major Canadian news outlet and have become a trusted resource for people seeking natural (effective!) birth control, a more joyful sex life, and an empowered journey to motherhood.