Does Fertility Awareness Method Work?

Dr. Jolene BrightenPublished: Last Reviewed: Fertility Leave a Comment

Does fertility awareness method work? This is a very common question in my practice and today I want to share with you a quick review of the different methods and what we know about the effectiveness of each. Plus I’m going to share with you what I recommend to my patients!

But you may be thinking…Who would want to learn an Fertility Awareness Method? 

Some women use this method to gain a better understanding of their hormones and how their menstrual cycle works, while others use it as a means of optimizing fertility or as an alternative for preventing an unwanted pregnancy.

It is common for women to experience side effects with birth control pills and other hormonal methods of birth control, some of which make it completely impossible to use these hormones and have any resemblance of a normal life. For these women, a non-hormonal option is the only option.

And with the recent termination of the male birth control trial, many women are questioning if they should continue on with hormonal contraception, after all, the side effects the men experienced were milder than that of women, but still warranted the study to be stopped.

There's many reasons women choose to learn the Fertility Awareness Method and today, I want to examine how well this method really works.

Before we dive in I want to say this — many people, including doctors, are quick to dismiss this method, claiming that women are too lazy or too easily confused by their own bodies to successfully use this method.

I disagree.

My experience is that women are motivated to understand their body and prevent pregnancy. And I would argue that the only person who truly understands your body is you. Instead of dismissing women, doctors should be teaching them how their body works and the signs and symptoms of healthy hormones.

So, with that said, let’s dive in.

What is Fertility Awareness Method?

Fertility awareness method (FAM), also known as natural family planning, is a non-hormonal and non-invasive approach to birth control. It is designed to teach you how to predict the signs of ovulation based on the signals your body is providing you. While it is sometimes referred to as the Rhythm Method, these are not the same thing. In this article, I'm going to describe for you what FAM is and provide you the low down on what the research says about how effective it is.

It is based on the following concepts:

  • You ovulate one egg only in each menstrual cycle.
  • The eggs lives for no more than 24 hours.
  • Sperm can live five to even six days in the uterus.

A woman ovulates only one day, but sperm can live for many, which means that you are potentially fertile seven to eight days out of your cycle. Yes, you are technically fertile up to six days before you ovulate because of those sperm that are swimming so diligently to reach that egg can live up to six days.

If you can NOT and do NOT want to become pregnant, you will either need to use another means of contraception or abstain from sex during your ovulatory window. Most people wanting to ensure there is no chance of pregnancy elect to use a condom or other form of contraception during this time.

But even if you don’t think this is NOT the method for you — I ask that you consider at least using it as a means of getting to know your body.

Download your FREE Hormone Starter Kit with 7 Day Meal Plan & Recipe Guide Book. This package is designed to get your hormones back on track!

If you’re using some form of protection other than the pill, I recommend using FAM to tune into your internal rhythms and gain greater insight into your body. After all, it is when you know how things should work that you can identify where the shifts need to happen to create harmony in your body and your life.

But to the question I am sure you’re dying to know the answer to…

Does Fertility Awareness Method Work?

It’s an excellent question and one I immediately asked myself. I want to share four common methods to help answer this question.

The Standard Days Method

Using the Standard Days Method, one clinical trial showed that out of 500 women over the course of 13 cycles, the pregnancy rate was <5 per 100 women in a year with correct use. Typical use saw pregnancy rates of 12 per 100 women.

The Standard Days Method is the easiest to use and requires the fewest days of abstinence or barrier contraception. Using this method, women avoid unprotected sex day 8 of their cycle through day 19.

PCOS, breastfeeding women whose period has not returned, recently postpartum women, and perimenopausal women are not advised to use this method as pregnancy risk is higher due to the irregular nature of their cycles. In fact, none of the FAM methods are recommended for women in these stages.

It is advised that cycles be between 26 to 32 days to successfully use this method.

Cervical Mucus or Ovulation Method

The World Health Organization conducted a large study in the early 1980’s, which included 725 women from 5 countries. They found that with correct use, 3 out of 100 women became pregnant. But with typical use, failure rate was 23 per 100 women.

The large failure rate reflects the necessity of thorough counseling by health care providers to ensure women understand how to correctly use this method. Three pregnancies per 100 women annually is a low failure rate, but when compared to the typical use we can see how important it is to use this method correctly.

The cervical mucus method requires women to evaluate cervical secretions several times daily to determine their fertile days. This method requires more time to teach than any other method, which may be the contributing factor to the high failure rate among typical users.

This method also requires that you abstain or use a barrier method during sex about 14 to 17 days out of the month.

TwoDay Method

Pregnancy rates using this method correctly have been shown to be 3.5 per 100 women per year. Typical use pregnancy rates were <14 per 100 women. It is thought that the simplicity of this method contributes to a lower typical use pregnancy rate as compared to the Cervical Mucus Method alone.

In one study, 4,000 cycles were analyzed in women using the TwoDay Method and found that the average number of fertile days was 13. This means that women need to avoid unprotected intercourse 13 days out of the month while using this method

In the TwoDay Method, users avoid unprotected sex on all the days that cervical secretions are present. There is no guessing if it is fertile cervical mucus — all secretions are considered a sign of fertility.

Symptothermal Method

When used correctly, the symptothermal method has been shown to have a first year pregnancy rate of 1.8 per 100 women when used correctly. And interestingly, the same study showed that after 13 cycles the pregnancy rate was only 0.6 per 100 women when there was no unprotected sex in the fertile window. With typical use, the pregnancy rate is between 13 and 20 per 100 women.

The symptothermal method is based on changes in cervical secretions and basal body temperature produced by hormonal changes during the menstrual cycle. In this method, intercourse is avoided or a barrier method is used:

  • All days with cervical secretions
  • Four days after the last day of cervical secretions
  • Six days following a 3 day spike in temperature

While this method may sound a bit cumbersome, it actually provides incredible insight into your health, especially your hormonal health. Gone are the days of paper calendars and pencils (I was never very good at those anyways), new fertility devices make tracking your fertility even easier.

Do Fertility Apps Work?

A word of caution… In one study, 95 apps that claimed to be for fertility were examined, with over half (55) of the apps being excluded because they either didn’t have any evidence-based methods as part of their technology or they included a disclaimer that they were not intended to avoid pregnancy. Yes, read the disclaimers ladies!

Of the 40 apps they had left, only four accurately used the Symptothermal Method. Yes, you read that correctly — ONLY 4 were accurate. The four they that were noted were Sympto, LilyPro, Lady Cycle and

Only one was found to use the Standard Days Method (CycleBeads).

But perhaps the most important conclusion of this study was this — “Relying solely on an app to use an FABM, without appropriate training in the method, may not be sufficient to prevent pregnancy.”

Or in other words…you need to be taught the FAM in conjunction with the app, rather than expecting the app to be solely responsible for predicting your fertile window.

Does this mean you shouldn’t leverage the lady focused technology?

In my practice, I recommend women use technology in addition to their own knowledge about their body’s rhythms. I often recommend the Daysy fertility monitor to women who are wanting to not only master the art of fertility prediction, but are also wanting to monitor their body and gain greater insights into their health.

Yes, you can use these gadgets to biohack your hormones!

What’s the Daysy Fertility Monitor and How Does it Work?

Daysy is a mini computer that contains the data from literally millions of cycles. There’s a bit of “getting to know you” time when you begin using Daysy — initially Daysy will need to learn your cycle, but in doing so, it will compare your cycle to the data it has collected from other users to begin to predict ovulation.

Once there is enough “you” data, Daysy will begin comparing your new cycle information to your previous cycles and get even more honed in on when you might be fertile. Dasys gives you a fertile window that includes the earliest day you could possibly become pregnant.

Daysy is color coded, making it really easy to decipher where you are in your cycle. Every morning (the moment your eyes pop open) you will take your temperature using Daysy and she’ll give you a clear signal via a colored light to tell you what to expect that day.

Green – Infertile days (think green light = go)

Yellow – Caution Days

Red – Fertile

Purple – Menstruation

The shift in your hormones causes shifts in your Basal Body Temperature. Daysy uses a complex algorithm to determine when your temperature spikes, which accompanies ovulation. And just like it takes 3-4 cycles to get enough data to predict your ovulation with any other FAM, Daysy also takes several months in getting to know you.

How Effective is Daysy?

To explain, let me begin to telling you about the Pearl Index. The Pearl Index is used to report how effective each form of birth control is. The lower the number, the more effective the method is and the lower the risk of pregnancy.

For example, IUDs have a Pearl Index of about 0.1 to 2.2 and birth control pills are at about 0.1 to 0.9.

As an aside, there’s been evidence that the Pearl Index may actually be higher for birth control pills than previously thought. In one review, birth control pills were found to have a Pearl Index of 4, which is thought to be more representative of actual users in the market, opposed to those who are knowingly participating in a study. Because of this, there is an expectation that failure rates for the pill will be higher than what studies report.  

Ok, back to Daysy!

Where does Daysy fall on the Pearl Index? They report a Pearl Index of 0.7.

That means for every 100 women using this method in a year, you can expect 0.7 of them to become pregnant.

Or in other words…It is 99.3% effective.

I’m liking those odds!

If you’re interested in learning more about Daysy you can check them out here.

What to Do Next if You’re Considering FAM?

Meet with a FAM Provider

This might be a doctor, a nurse, a provider at Planned Parenthood, or one of the amazing FAM educators out there. But you want to find someone who will take the time to teach you the method in detail. Remember, FAM works when women use it correctly, so let this empower you to take charge of your fertility.

Speaking of taking charge of your fertility….

Read Taking Charge of Your Fertility

This book is hands down one of the best resources out there for learning about your menstrual cycle and navigating your fertility. You can grab a copy on Amazon here.

Weigh Your Options

You’ll hear many experts say that Fertility Awareness Method is not very forgiving when it comes to user error. It’s true, the side effect of FAM is pregnancy, which can be a really big deal if you aren’t expecting it…or interested in having a baby.

But when you look at the research, you’ll find that no contraceptive is 100% effective at preventing pregnancy and that they all come with their fair share of side effects, which also include pregnancy.

At the end of the day, it is you who will need to decide which side effects you’re ok with and which method you think will suit your life best.

Weigh your options and make the decision that feels best for you. And if you decide that FAM is not your preferred method — no worries. But I do hope you will at least use it to learn more about your body.

The data your menstrual cycle, including the fertile window, provides provides a great deal of insight into your hormones and your overall health. After all, you’re period is considered the 5th vital sign!

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About The Author

Dr. Jolene Brighten

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Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.