Is Fertility Aware Contraception Right for You?

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If you’ve ever texted, DMed, or said the words “birth control” to your friends over the past few years, you’ve probably seen ads that said there was an app for it. Some companies promise that tracking your cycle with their app and their algorithm will help you prevent pregnancy—no hormones, implants, or IUDs required.

All birth control apps rely on a birth control method that has always existed called Fertility Information . Basically, you write down certain physical characteristics every single day to keep track of your menstrual cycle until you can predict ovulation like clockwork. Avoid unprotected sex during and before ovulation and you are unlikely to get pregnant. When done correctly, this method is effective, but how effective it is is a matter of debate.

This is what has led to controversy around birth control apps like Daysy andNatural Cycles . As with any birth control method, the effectiveness of birth awareness depends on how correctly and consistently you use it. But unlike condoms or the pill, we don’t have a clear idea of ​​what “average” fertility awareness use looks like, and there’s little scientific consensus on the quality of the research behind those ” 93% effective!” claims. Claims about the effectiveness of the FDA-approved Natural Cycles app were investigated and approved by the Swedish medical authorities , but were deemed misleading enough by the UK to ban some advertisements . Despite serious allegations of incorrect data collection and analysis , Daysy is is still on the market, making it difficult for potential users to ignore the hype and make an informed decision about contraception.

On top of that, there is a lot of misinformation about contraception for fertility in general. Ardent proponents often overestimate its effectiveness, while naysayers are too quick to dismiss it, while making rather crude assumptions about the people who use them. To clarify, I spoke with research scientist Dr. Chelsea Polis and ob/gyn Dr. Rachel Peragallo Urrutia, who conducted a systematic review of fertility awareness research . Whether you’re intrigued by the idea of ​​a birth control app, or just want to learn more about fertility issues, here’s (almost) everything you need to know to decide if it’s right for you.

What is Fertility Awareness-Based Contraception?

Fertility Awareness Based Methods, or FABM, aims to prevent pregnancy by dividing the menstrual cycle into “fertile” and “non-fertile” days. On fertile days, the chances of getting pregnant from unprotected sex are highest; on non-fertile days it is lowest. Finding out which days is done by carefully tracking biomarkers or physical indicators of where in your cycle you are.

There are several relevant biomarkers that you can track, which means there are several FABMs to choose from. These are the most common types:

Calendar methods, like the traditional “rhythm method”, track fertility by calendar days of the menstrual cycle. Once you are familiar with the length and regularity of your periods, you can use the standard menstrual cycle timeline to determine your most and least fertile days. For example, in the standard days method, cycle days from 8 to 19 are considered fertile.

Cervical mucus (or ovulation) testing methods track ovulation by looking for changes in cervical mucus, which sounds exactly like it: the mucus that comes out of the cervix. Its consistency and appearance change in response to the hormonal fluctuations of the menstrual cycle, becoming characteristically rubbery and slippery just before ovulation. The simplest slime method is the two-day method : any day you observe this slime is considered fertile, just like the day before.

Basal Body Temperature (BBT) methods also track ovulation, which causes a small but measurable rise in body temperature. Every morning, before you get out of bed, you take your temperature and record it on the app or manually on graph paper. No matter how you record the readings, the goal is the same: to determine the temperature jumps that accompany ovulation. The Natural Cycles app, which can use temperature data from the Oura ring or Samsung Galaxy watches , is an example of the BBT method.

Urine hormone-based methods use a device called a contraceptive monitor to check the levels of estrogen and other hormones in the urine. These measurements are entered into an algorithm that calculates the fertility window.

Any of these single biomarker methods can prevent pregnancy when used correctly, but you can also combine them for more information. The use of the BBT method in combination with the calendar and/or mucus method is a symptothermic method ; replacement of BTT with urine hormones makes it a symtohormonal method.

This is very similar to natural family planning (NFP). It is the same?

Yes and no. From a scientific point of view, there is no real difference – NFP and FABM use the same methods – but there is often a significant difference in their social and moral attitudes. As the Association of Fertility Professionals (AFAP) explains, NFP has traditionally been taught in a Catholic context :

“Most NFP methods advocate chaste abstinence (abstaining from any sexual activity) during the fertile phase of the cycle if the couple wishes to avoid pregnancy. The NFP discourages sexual activity outside of marriage and often restricts education to heterosexual, engaged or married couples.”

On the contrary, fertility awareness is intentionally inclusive. AFAP welcomes all people regardless of gender, sexual orientation, religion, or marital status, and openly supports the “full spectrum of reproductive options” including condoms, fertility treatments, and abortion.

Benefits of Fertility Awareness Techniques

The most important thing to remember about FABMs is that they are nothing but another birth control option. Like any other method, you will have to weigh the pros and cons.

No hormones means no hormonal side effects.

Hormonal birth control has side effects ; there is no way around this. While some of these may be positive — lighter periods, fewer acne, milder PMS — finding the right hormone cocktail can take literally years of trial and error. For this and other reasons, non-hormonal methods such as FABM have their advantages: Like copper IUDs and condoms, FABM does not cause unpleasant hormonal side effects. But unlike IUDs, FABMs do not require a painful insertion process and do not affect the menstrual cycle. And, unlike most condoms, latex allergy is not a problem.

Many methods are free or inexpensive.

Physical and financial accessibility is another plus of FABM. Once you know what you’re doing, the only equipment you’ll need to check cervical mucus is your cervix, your finger, and a calendar or chart. You take measurements on your own, according to your schedule, without leaving your home.

Of course, some companies are looking to monetize fertility awareness, especially in terms of education. In itself, this is not necessarily a bad thing: correct use requires a certain level of knowledge. Classes or individual consultations with licensed medical practitioners are not free, but many are inexpensive or charge on a sliding scale. And while neither is strictly necessary, a fancy thermometer and app subscription can still cost less than an OB/GYN appointment and a monthly prescription, depending on your insurance.

All power is in your hands (and your partner)

Tracking and recording biomarkers every day for years gives you a better picture of your reproductive health than taking pills or occasionally remembering the existence of an IUD. Depending on how much you enjoy tracking health indicators and your experience in the healthcare system, this can be quite helpful.

Using FABM also requires close communication with your partner(s) and practitioners. For people with healthy, mutually supportive relationships, teamwork can be beneficial; from the point of view of a doctor, treating a patient with a conscious interest in his health is a pleasure. Urrutia told me that she enjoys infertility consultations because they represent a “real partnership” between her and the patient.

What are the disadvantages of fertility-based contraception?

Depending on your point of view, FABM’s biggest advantage may also be its biggest disadvantage. These methods are the opposite of “set it and forget it”—they require at least two people to actively participate every day, making them especially vulnerable to human error. But beyond that, one of the most frustrating hurdles in learning about FABMs is how little we know for sure about their uses and effectiveness.

It’s not immediately effective.

The transition to FABM is neither quick nor easy. There is a build-up period during which you track your chosen biomarkers every day, ideally not having unprotected sex at all. Even if your periods are going like clockwork, this introductory period can last from one to three cycles: you need to know what “normal” looks like, but you also need time to get used to the methods.

Irregular periods complicate the adaptation process. If you stop taking your pills, have recently given birth and/or are breastfeeding, are in perimenopause, or have a medical condition that causes irregular periods, it may take longer, up to six months, to establish this baseline. The result, according to Urrutia? “You can’t just jump like that.” In other words, until you really get the hang of biomarker tracking and do it long enough to accurately predict fertile days, you can’t rely on FABM alone to prevent pregnancy.

There is no protection against STIs or STDs.

Like any non-barrier contraceptive, FABM does not protect against infections and sexually transmitted diseases. If your sex life involves any risk of infection and you rely on FABM to prevent pregnancy, be sure to use a barrier method such as condoms to prevent STIs.

Do Fertility Awareness Techniques Really Work?

Almost all other methods of contraception have been thoroughly studied. We know with a very high degree of certainty how many people use pills, how reliably they use them, and how often pills fail under normal or ideal use .

Almost all of this does not apply to FABM, which rarely become the object of clinical trials. Since they are not widely used, this makes some sense; The potential pool of study participants is initially small and continues to shrink as exclusion criteria are applied. The data behind fertility apps often comes from private labs, so it’s proprietary – you can’t just Google the results. Even peer-reviewed articles on FABM are not always reliable: they may be statistically insufficient, rely on self-reported or carefully selected data, show severe flaws in experimental design , or all three . Some studies even combine all FABMs into one method, which hides a big difference in their effectiveness.

Unfortunately, all of this means that there is a serious lack of peer-reviewed data on FABM, and when it comes to making informed decisions, this is the biggest hurdle for both healthcare providers and patients.

The effectiveness of ideal and typical use is not clearly defined.

Of the nearly one million criteria to consider when choosing a contraceptive, most people focus on two numbers: its effectiveness with ideal use and its effectiveness with normal use. Knowing what makes them different and your tolerance for that difference is extremely important.

Ideal use is more or less what it sounds like: using a contraceptive method exactly as instructed every time. The policy defines it as “the performance we expect from a person who uses the method correctly and consistently every time.” Obviously, it is at this point that contraception is most effective; ideal use results in high efficiency or low failure rates, depending on your point of view.

Common usage, she explains, is less straightforward. “In short, typical use is the efficiency that can be expected from the average person. … It includes some leeway in not following exactly the instructions for a method every time you use it.” This means that typical usage efficiencies are lower (and bounce rates are higher) than ideal usage.

The definitions of typical and ideal use do not change from method to method, but what they actually look like does. As Dr. Polis explained, there are a lot of checkboxes for the ideal use of FABM: “[It requires] perfectly tracking all the biomarkers involved in using this method, interpreting them perfectly, and then completely avoiding unprotected sex on a case-by-case basis. a day that is considered fertile.”

If you can check these boxes consistently, FABMs are effective, but reliable data on their ideal usage can be hard to come by. According to a systematic review published by Urrutia and Polis , one study found that Billings’ mucus-only ovulation method could result in as little as one unintended pregnancy per 100 person-years when used absolutely correctly. In other words, if 100 people used the Billings Ovulation Method perfectly for a year, we would expect to see one unplanned pregnancy. For the calendar standard day method, this number is 5; for the two-day mucus-only method, 3.5.

Typical FABM usage data is a little easier to find – for some methods, that’s all we have – but the numbers are inconsistent, even within methods. In typical use, the Billings method can result in 10 to 33 unintended pregnancies per 100 person-years, depending on the study. For standard days, this is 11-14 pregnancies; 14 for two days. Even if you know that typical use reduces effectiveness and are realistic about your behavior, there is a big difference between 10 and 33 unplanned pregnancies.

In many ways, this is why the FABM discussion is rife with misinformation. Without reproducible, rigorously verified performance data from independent research, it’s hard to know exactly what you’re signing up for, especially when marketing jargon comes into play. Natural Cycles and DaysyView, which use the BBT method, have faced backlash over advertised typical usage rates. But investigating the validity of these allegations, and then taking action if they are legitimate, can be a painfully difficult process. In June 2018 , Polis published a critique of the study used in the marketing of DaysyView in reproductive health (which also published the original study), citing serious analytical and methodological weaknesses. Based on her comment, the article was retracted , but she was sued by the company that created Daysy. (The lawsuit was ultimately dismissed.)

How to choose the method that’s right for you

If the pros and cons of FABM match your lifestyle and you want to get started, you’ll need to do some research first. But doing medical research online is difficult, confusing, and potentially dangerous. How can you filter out garbage?

Look for high quality sources

According to Polis, the best thing you can do is avoid the hype. There are many people who would like to profit from your decision to use FABM, whether it be a beautiful app, an expensive training program, or even a book. In this sense, she has a specific recommendation: “Try to avoid contacting social media influencers who will help you make a decision about contraception.” With that said, it is possible to obtain quality information from commercial sources if you know what to look for, namely a detailed and clear explanation of all the risks and benefits.

If you’re just starting out and don’t know where to turn, try the FABM FAQs from Planned Parenthood , AFAP , and the American College of Obstetricians and Gynecologists (ACOG). For a more in-depth discussion that is still user-friendly, Polis has a Twitter feed where she talks about all things contraception; Answer The OB/GYN where Urrutia practices has an entire page dedicated to FABM . If you prefer to search for literature right away, the Gutmacher Institute is a great resource.

If possible, find a qualified specialist.

Some FABM methods (notably Billings Ovulation, Marquette, and Sensiplan) actually require training from a professional certified to teach that particular method. No federal accreditation commission; certificates differ depending on the method. If you are interested in any FABM, especially one that requires instruction, use the AFAP Directory of Practitioners to find a qualified tutor in your area, or online – most practitioners offer virtual consultations.

It’s worth noting that while a trusted doctor can be an excellent guide, your OB/GYN may not be able to help; as Urrutia explained to me, FABMs are not part of formal OB/GYN education. On the positive side, doctors who offer FABM consultations (like Urrutia) usually do so out of a genuine passion for their job – so if you can find one, they’ll probably be happy to work with you.

Be honest with yourself and your doctor

When counseling a patient interested in FABM, Urrutia’s main goal is to understand his reproductive plans. This includes many questions, all of which must be answered honestly and completely in order for her to make a recommendation: “Do you want to have children? Do you want to have more children? When do you want to have [these] children? What is your relationship? … How much work do you want to do to make sure your method is effective? What [birth control methods] have you used in the past and how was it for you?” She also highlighted that screening patients for intimate partner violence is an important part of this assessment: FABMs require mutual trust, respect, and honesty, which are not found in relationships that involve physical or emotional abuse.

If you think this is too much, then it is. Choosing a contraceptive method is a big, potentially life-changing decision, and you deserve to know what you’re getting into. Know yourself, know your offenders, and take as much time as you need to make the best decision you can.

Updated April 2019: Edited to clarify that Natural Cycles’ ads were banned by the UK Advertising Standards Authority, not the app itself. In addition, the study used in Daysy’s marketing materials is a retrospective survey and not a clinical study.

Updated September 1, 2023: Edited to reflect that after our initial publication, the Daysy study was withdrawn, the company sued Polis, and the lawsuit was later dropped.