Natural Birth Control Can Be 99% Effective And It Doesn't Ruin Your Body—Here's How It Works

Fertility awareness-based methods (FABMs) are a natural alternative to contraception that give women the tools they need to make informed family planning decisions in a way that works with their biology instead of against it. Rather than turning off our fertility with a pill or an implant, FABMs help women to prevent pregnancy naturally by understanding when they are fertile and infertile throughout each menstrual cycle.

FABMs help women to prevent pregnancy naturally by understanding when they are fertile and infertile throughout each menstrual cycle.

While a lot of women like the idea of using a FABM, switching to a natural method can feel risky and difficult to navigate. It's certainly more work than taking a pill each morning, but with proper instruction and application, FABMs have been proven to be an effective, empowering tool for women wishing to postpone pregnancy.

How Do Fertility Awareness-Based Methods Work?

While different FABMs may emphasize different fertility signs and have slightly different rules, all methods work in generally the same way—by helping women recognize when they are fertile and able to become pregnant each cycle. Women can then use this knowledge to avoid intercourse during their fertile days and thus avoid pregnancy.

I use and teach a FABM called the sympto-thermal method. I like this method because it allows a woman to track multiple fertility signs at once, primarily her cervical mucus symptoms ("sympto") and basal body temperature (“thermal”).

The changes a woman observes in her cervical mucus pattern and in her temperature over the course of each menstrual cycle reflect the hormonal changes taking place within her body. These observations are recorded on a fertility chart, creating a blueprint of her fertility, where she can visually see when she is fertile and infertile each cycle.

These observations are recorded on a fertility chart, creating a blueprint of her fertility, where she can visually see when she is fertile and infertile each cycle.

Cervical Mucus

One of the first things a woman will learn to do when using a FABM is to chart her cervical mucus. It’s a vital part of our fertility, yet few women are ever taught what it is (and women using the pill may not have any). Simply put, cervical mucus is what keeps sperm alive and helps them reach the woman’s egg. You can’t get pregnant without it.

Generally, a woman will transition from seeing no cervical mucus at the beginning of her cycle, to seeing a sticky fluid when using the bathroom, before eventually observing egg-white type mucus close to the time of ovulation. This progression takes place because a woman’s estrogen level rises as her body gears up to ovulate, making cervical mucus a key sign of fertility. To use cervical mucus to track fertility, a woman should check for mucus on her toilet paper every time she uses the bathroom, both before and after she voids, and then record her most fertile observation at the end of each day.

Cervical mucus is what keeps sperm alive and helps them reach the woman’s egg. You can’t get pregnant without it.

A FABM instructor can help a woman decipher her own cervical mucus pattern and then recommend personalized guidelines to follow in order to avoid pregnancy. Generally speaking, all cervical mucus is an indication that a woman has entered her fertile window, and that pregnancy would be possible if she were to have intercourse during that time. There is a bit of a learning curve to charting your cervical mucus, but after a couple of cycles, it becomes second nature.

Basal Body Temperature

The next fertility biomarker a woman using the symptom-thermal method records is her basal body temperature, or more simply put, her body temperature upon waking. This can be done orally with any basal body thermometer. A woman’s basal body temperature gives her insight into her fertility by allowing her to confirm ovulation. Just as the onset of cervical mucus alerts a woman to when she is entering her fertile phase, a shift in her basal body temperature communicates that she is exiting that phase.

While a woman’s cervical mucus correlates with her estrogen levels, her basal body temperature correlates with the hormone progesterone. Progesterone is the pro-gestation hormone produced after ovulation, and it causes a woman’s body to warm up slightly. Although this change in temperature is subtle — we don’t feel it — it's actually pretty easy to spot when consistently recorded on a fertility chart.

A woman’s basal body temperature gives her insight into her fertility by allowing her to confirm ovulation.

For best results, be sure to use a basal body thermometer. It’s important to take your temperature as soon as you wake up before doing anything that may cause your temperature to change, like walking around, eating, drinking, or smoking.

Additionally, you should try to take your temperature at the same time every morning. As with checking for cervical mucus, once you get into a habit of taking your temperature, it isn’t as much of a hassle as it may sound. There are very specific rules that must be adhered to regarding your temperature shift in order to avoid pregnancy, but generally, a woman can be considered infertile three to four days after her temperature rises. Make sure to seek the advice of a fertility awareness instructor about what specific guidelines you should follow, because every woman’s cycle is different.

Is It Effective?

As a SymptoPro Fertility Education instructor, one of the most common concerns I hear about FABMs has to do with whether or not they're actually effective when it comes to preventing pregnancy. It’s a question worth asking, and thankfully, there have been several different studies performed that show that FABMs can actually be just as effective as hormonal contraceptives when used correctly.

FABMs can actually be just as effective as hormonal contraceptives when used correctly.

One 2007 study of the symptom-thermal method concluded that the method was highly effective, with an unintended pregnancy rate of only 1.8 per 100 women with typical use. With perfect use, the unintended pregnancy rate was even lower at .6 per 100 women. Other fertility awareness-based methods have similarly high effectiveness rates. Studies of the Creighton Model determined a 99.5% effectiveness rating while the Billings Ovulation Method came out at 99% effective.

Interestingly, a study of the Billings Method among a cohort of Indian women living in impoverished areas of Delhi even concluded a user effectiveness rate of 97.43%, revealing that FABMs are accessible to women of just about every educational background and socioeconomic class.

FABMs are accessible to women of just about every educational background and socioeconomic class.

In short, modern FABMs are easy to navigate and highly effective with proper use and instruction. Cervical mucus alerts a woman to when she is becoming fertile, and a rise in her basal body temperature lets her know when her fertile window is ending. The ability to cross-check these two biomarkers leaves us with a highly effective natural method of avoiding pregnancy that allows women to work with their biology instead of against it.

Closing Thoughts

It's certainly more work than popping a pill every morning, but after eight years of using this symptom-thermal method myself, I can say that the knowledge gained is incredibly rewarding. To learn how to effectively use a fertility awareness-based method, I recommend taking a class through an established fertility awareness or natural family planning organization such as SymptoPro Fertility Education. You can find more about my classes through The Guiding Star Project.