What is the sympto-thermal method of fertility awareness?

DSC01590Learn more about what the sympto-thermal method of fertility awareness is and how you use it

I want to start with the simplest of all simple: The sympto-thermal method of fertility awareness is a natural birth control method. It works because you actually only have about 9 days (average, this can vary a lot from woman to woman) each cycle that you are fertile. During these days, you actually have observable biological signs that are associated with what your hormones are doing at any given time. Observing these signs, charting them, and applying a couple of rules will determine your “fertile window.” You can use this as birth control by avoiding unprotected intercourse during your “fertile window” in favor of another method.

I’m guessing, though, that you want more information than that. That’s why you are here, after all, right? No problem, read on.

What the sympto-thermal method isn’t

First of all, I want to touch on common misconceptions. The method that I teach is called the sympto-thermal method of fertility awareness. It’s often just referred to as “the fertility awareness method” or “natural family planing.” Why the differentiation?

There are many methods that are classed under a large umbrella term called “fertility awareness based methods.” Some of these methods are quite different, but they all have one thing in common: They leave your fertile period intact and try to determine the days you are fertile, recommending abstinence, barrier, or alternate sex during that time.

Did you catch that last part? “Try to.” Unfortunately, some fertility awareness based methods contain woefully outdated and ineffective methods. This terms even encompasses the rhythm method, based entirely off of calculations of past cycles. We’ve all heard the joke:

What do you call people who use the rhythm method? Parents.

Of course, it’s not necessarily true, but not far off.

The big problem with calculations is that your cycles can change. They can change from cycle to cycle if you you aren’t regular, they can shift based on age or changes in lifestyle, they can change randomly as a one off because of sickness or stress. It’s just not reliable to base your fertile window off of what has happened to you in previous cycles. It’s even less accurate to base your predicted ovulation off of the mythical 28 day cycle.


So how is the sympto-thermal method different?

Enter the sympto-thermal method. We are lucky enough to have people that have devoted their lives to the research of the female reproductive system and hormones. Because of that, we know all of this:

  • Sperm need cervical fluid to survive, swim, and be effectively “washed” and capable of fertilizing an egg. It can live in fertile cervical fluid for up to 5 days, but dies quickly in the natural acidic vaginal environment.

  • Cervical fluid builds up in response to estrogen, which is released by the developing sacs that hold the egg. This is happening in the days leading up to ovulation.

  • The egg can only live for 12-24 hours, and ovulation can only happen once in a cycle. If two eggs are released, the second comes within 24 hours of the first, after which ovulation is inhibited by high levels of progesterone.

  • Progesterone is released from the corpus luteum, which is what the sac that held the egg turns into after ovulation has taken place. This raises the body temperature, dries cervical fluid, and inhibits a second ovulation.

I know right now some of that may still seem foreign to you, but let me go over what happens during a typical menstrual cycle.


An overview of your hormonal cycle

The beginning of the period is considered DAY 1 of your menstrual cycle. Near the time that the period is ending, your pituitary gland (which is at the base of the brain) secretes something called follicle stimulating hormone. Follicle stimulation hormones stimulates a follicle (who would have thought?) to begin maturing. The follicle is a sac of cells containing an egg. Each cycle, about 12-20 follicles begin the maturation process, though only 1-2 are actually released.

As the follicle matures and grows bigger, it starts to secrete increasing amounts of estrogen. This estrogen does two important things: It starts the production of the first of the observable fertility signs – cervical fluid and it grows the uterine lining. It is because of the reliability of estrogen creating cervical fluid and sperms need for cervical fluid to survive we can use this sign to predict the beginning of the fertile window.

As estrogen reaches a critical point, the pituitary then sends out a rush of luteinizing hormone. Luteinizing hormones stimulates more estrogen, and estrogen more luteinizing hormone. They both rise steeply for 1-2 days. This spike in luteinizing hormone is the actual catalyst for ovulation. Ovulation is the actual release of the egg from the follicle.

At this point, the luteinizing hormone does it’s work on the follicle and “luteinizes” it, making into something called the corpus luteum, which continues to secrete estrogen like the follicle before it did, but now also secretes progesterone in a high amount. The estrogen continues to help the uterine lining grow, but the progesterone dominates. This means that your cervical fluid dries up, your basal body temperature spikes (this is your second observable fertility sign), and the uterine lining is matured in case of an implantation.

The corpus luteum has a finite life span of about 12-16 days. If there is no conception, hormone levels drop off sharply and the lack in hormones stimulates the uterine lining to shed, starting a new cycle.

The first part of this cycle, from the first day of your period until ovulation is called the follicular phase. The second part of the cycle, from ovulation until the day before your next period begins is called the luteal phase.

I am betting after all of that you could use a visual, it’s something like this:

Menstrual cycle animation

Comic by Jorge Muniz

Whew, quite a process, and to think your body goes through all of this each cycle!

Lucky for us, we not only have all of this scientific information on how to make a real evaluation of our fertile window, but we also have studies on this method used as birth control, and guess what? It’s 99.6% effective.


So what does this all mean for you in your daily life?

So what do you actually have to do everyday to use the method? First things first, you should take a class. If a class isn’t for you, I suggest reading a book and getting a follow-up from a real, live fertility awareness educator. It’s definitely good to make sure you have got everything down before using it as birth control.

On a daily basis, you are taking your basal temperature (meaning your waking temperature) and checking your cervical fluid. You end up checking your cervical fluid when you are going to the bathroom. Conveniently, at that time, you already have your pants down and are ready for action.

Taking your temperature is as easy as rolling over in bed, snagging your thermometer, sticking it in your mouth and snuggling in bed for an extra minute. Cervical fluid is as easy as using some toilet paper to wipe your vulva, seeing if you can get anything off of the toilet paper and checking what it’s like. You just write down your most fertile cervical fluid check and your temperature at the end of the night.

Written out, it may look like a lot, but you end up doing it on autopilot after you’ve been at it for a couple of cycles.

There is both good and bad to the method, as it is for all birth control

  1. No adverse effects on your health.

  2. Extremely effective with good education and correct use.

  3. It is empowering.

  4. Encourages partner participation in birth control.

  5. Creates self awareness and responsibility for one’s health.

  6. Helps the women and/or her physician see a possible hormonal issue.

  7. Low cost at first, and no recurrent costs are associated with it.

  8. It’s good for the environment – No artificial hormones getting in our waterways and no packaging to discard.

  9. Most users find a deep body appreciation.

  10. Opens one up to their sexuality in new ways.

  1. Most people want to have sex the most during the time they can get pregnant. That’s just the facts of life.

  2. You have to chart every day (Note: I. Hannah Ransom, hate charts and records and anything I must pay meticulous attention to, but I do not have one bit of problem keeping my STM charts).

  3. It requires time to learn and assimilate, motivation (if you are relatively ambivalent about pregnancy there is a good chance you will not be diligent in abstaining or using a barrier), and it requires you to use the method correctly and consistently (it’s not like getting an implant or IUD).

  4. And of course, this does NOT protect against STIs. Only condoms can reduce your chances with them.



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