This excerpt from The Cycle was written by Jennifer Aldoretta
Using the rules of the sympto-thermal method of fertility awareness (STM), you can determine when you are no longer at risk of an unintended pregnancy or when you baby-making window has passed! Not just this, but monitoring these fertility signs on a daily basis allows for faster detection of many reproductive disorders, including polycystic ovary syndrome (PCOS), anovulation, luteal phase defect, thyroid hormone imbalances, or estrogen and progesterone imbalances. While this book is not meant to diagnose or help you self-diagnose any reproductive disorders, practicing STM can help your physician work with you to reach a timelier, more cost-effective, and less invasive diagnosis. This section will discuss how to check all of the fertility signs we’ve learned about up to this point.
There are several guidelines to follow in order to get the most accurate daily BBT reading.
Use a thermometer that measures in 0.1 °F (0.05 °C) increments or smaller;
Measure BBT at about the same time everyday, first thing upon waking;
Get at least three consecutive hours of sleep before measuring BBT;
Be consistent taking temperature either orally or vaginally; and
Be mindful of events that can skew temperature readings (like alcohol use, illness, and lack of sleep, among others)
It’s imperative to get a precise temperature reading when measuring BBT because the changes that occur are subtle, yet distinct. This means the thermometer that is used is of the utmost importance. Many Fahrenheit fever thermometers you’ll find in drug stores measure in 0.2 °F increments, which isn’t sensitive enough for the purposes of practicing STM.
Using a basal thermometer is often the best bet, since they are usually more precise than necessary. Basal thermometers can be found at most drug stores in the family planning section and can be purchased for about $10. Practicing STM only requires Fahrenheit temperatures that are accurate to the 1/10th degree (or 0.1 ºF), so if a Fahrenheit basal thermometer reads 97.69 °F, only record the first three digits (97.6 °F). Never round!
Basal thermometers that record Celsius may be accurate to the 1/100th degree (or 0.01 ºC), so for those using Celsius, round temperatures to the nearest 0.05 ºC if you’re charting on paper (most pre-made Celsius charts have a y-axis that increases in increments of 0.05 ºC). For example, a Celsius BBT reading of 36.62 ºC would be rounded down to 36.60 ºC, and a reading of 36.73 ºC would be rounded up to 36.75 ºC.
Basal body temperature is the core temperature of the body at rest. During the day, our core temperature fluctuates from physical activities as minor as walking around, so taking BBT first thing upon waking helps to eliminate these natural temperature variations. And when I say first thing in the morning, I mean first thing in the morning! Even just getting up to use the bathroom or sitting up in bed is enough to skew temperatures for some folks. There are several times that I’ve jumped out of bed and high-tailed it to the bathroom, only to realize mid-pee that I hadn’t taken my temperature! I took it as soon as I got back in bed without much harm done, but not everyone will be so lucky.
For those worried about taking it around the same time everyday, it may be helpful to do what I do: my dedicated BBT alarm goes off at 5 a.m. everyday, and after taking and recording my temperature, I happily go back to sleep until it’s time to start the day.
Since BBT is the body’s resting temperature, taking it after at least three hours of uninterrupted sleep will make for the most accurate result. Many people, like me, frequently wake up at night for one reason or another. There’s no harm in BBT being measured early as long as it occurs after about three consecutive hours of sleep. For those who have young children or frequently travel to different time zones, this may prove to be more difficult. However, some lucky ladies may find that they aren’t as sensitive and that the time of measurement doesn’t make a difference. The only advice I can offer to people in these unique circumstances is to do your best with what you’ve got! This might be easier said than done for many; the big takeaway is to be as consistent as possible and never take risks.
I’m one of those lucky people who wakes up every night to use the bathroom thanks to my laughably tiny bladder. Some nights I wake up at 2 a.m., get up to pee, go back to sleep for three hours, and then take my BBT at my usual 5 a.m. But on mornings when I happen to wake up at 3 a.m. or 4 a.m., I’ll simply take my BBT a little early that day before getting up to use the bathroom…no big deal. I’ve personally had much better results taking it a couple of hours early rather than taking it a couple of hours late, since my temperature tends to rise when I sleep in.
Minor fluctuations in BBT are expected, but it’s the pattern that we’re interested in. Once you becomes familiar with your unique cycle, handling small BBT variations will become second-nature.
The most accurate ways for you to measure your core body temperature are orally, vaginally, and rectally. Oral and vaginal temping will do just fine, since I’m pretty sure most of us aren’t terribly excited about the thought of taking our temperature in the bum. Taking BBT vaginally is often a better representation of your true core temperature, especially for those who sleep with their mouths gaping open, but taking it orally works perfectly well for most people. Switching between oral and vaginal temping in the middle of a cycle may skew BBT readings, so it’s not recommended. However, switching from vaginal to oral temping in between cycles is okay.
Decreased sleep quality tends to artificially increase BBT. The biggest offenders of this are illness (fever, flu, cold, etc.), lack of sleep or frequent waking, and alcohol consumption the previous night.
Anytime you’re sick with the cold or flu, even if you don’t have a fever, it tends to lead to higher basal body temperature readings—for male and female humans, alike. But when you’re using BBT to monitor fertility, it’s important to get it right. Lack of sleep and frequent waking affect BBT for more obvious reasons. Alcohol consumption, on the other hand, can be a bit of a gray area. Although everyone is different, having one or two drinks the night before will likely have no affect on BBT. A good rule of thumb to follow: if you wake up feeling like you were drinking the night before—and it doesn’t usually feel all that great—that’s a good indication that BBT will be artificially high and should be discarded from fertility calculations.
If you’ve experienced one of these events and think it might have affected your BBT but you’re not sure, it’s always best to play it safe and exclude that day’s BBT reading. Having a few missing temperatures isn’t a big deal, as long as behavior is adjusted when gaps in BBT might interfere with detection of the fertile or infertile phases.
Any discarded temperatures should be taken into account when calculating the post-ovulatory infertile phase. For instance, if on the third day after her temperature shift, Leslie thinks her BBT is artificially high for any of the previously mentioned reasons (or if she simply forgot to take her temperature), she would restart her three-day in accordance with the Temperature Shift Rule. Note that this is a very conservative approach.
However, if Leslie acknowledges and is okay with the extra risk, she would exclude her artificially high temperature and continue her three-day count the following day. Leslie would not consider herself infertile until she has three days of temperatures above the coverline that are not artificially high or missing. In this case, she would not be considered infertile until the fourth day after her temperature shift (assuming she only had one day with a missing or artificially high temperature).
Whether or not you have a vagina, the thought of inspecting cervical fluid might make you a bit uncomfortable. I can completely empathize with those feelings! My first reaction upon learning about tracking cervical fluid changes was: “I have to check my what?!” But trust me when I say that the wealth of knowledge gained by learning this stuff far outweighs any initial “ew” factor.
If you blew your nose and then noticed that your boogers were green, how would you react? Well, you’d probably think there was a problem! And what if you measured your body temperature right now? How would you know if you have a fever? How can we tell that multi-colored boogers or a fever indicate that we might want to see a doctor? Because we have a baseline to compare to and we know what normal looks like!
So why are so few vagina-wielders able to distinguish healthy cervical fluid? Like an elevated temperature and rainbow-boogers, regularly monitoring cervical fluid can indicate when something’s up, which is why it’s an important thing for every person to learn. We already encourage women to perform monthly breast self-exams, so shouldn’t we also encourage regular cervical fluid self-checks, if for nothing else, to support gynecological health? Uncovering the fertile window should simply be seen as an added benefit.
The cervix, as we well know by this point, produces cervical fluid. Since the type of fluid present determines whether sperm are able to survive in your body, it’s important to get an accurate representation of the type of fluid produced on any given day. The best way to do this is to check fluid at its source. Yep, that’s right. And it’s not even that scary. I urge partners (male or female) to partake in the fluid-checking…make it fun! Educating everyone about the ins and outs of practicing STM will make for a more confident and supportive partner when the method is being used to avoid or achieve a pregnancy.
One of the most convenient times to check fluid is just before using the bathroom, as the proper position has already been “assumed.” Checking after using the bathroom is an option, though there is the possibility of cervical fluid getting “washed” away by urine or being pushed out due to muscle contractions.
Using a (recently cleaned) middle finger, gather some cervical fluid by running the fingertip along the inner wall of the vagina as close to the cervix as possible. And, if you can reach it, gather fluid from the surface of the cervix. Gathering fluid from the cervix itself will provide the best representation of that day’s fluid type. The cervix is easily recognized because it feels like a protruding nub with a small dimple or opening in the middle (called the os). You can’t miss it…unless the cervix is particularly high that day, in which case it may be more of a struggle.
I’ve mentioned previously that for many people, there will not be any noticeable fluid for some parts of the cycle; however, a dampness will always be observed due to vaginal fluid. This fluid will feel similar to touching the inside of your mouth. After a couple minutes, vaginal fluid (like saliva) will evaporate from your finger; cervical fluid will not, which is an easy way to distinguish the two.
Once you’ve gathered fluid with your fingers, pull a sample using your other hand and then rub the cervical fluid between your finger and your thumb. Pay attention to what it feels like. Is it smooth? Is it sticky? Is it pasty or crumbly? Is it slippery? Or maybe there’s nothing there except vaginal fluid! Next, take a look at it. Is it white? Yellow? Clear? Finally, slowly pull your finger and thumb apart. Is it very stretchy? Does it form small peaks?
Other great ways to get a good idea of cervical fluid type is to pay close attention to the way things feel throughout the day: Do I feel wet or leaky? Another great indication is to pay attention to how easily toilet paper glides when you wipe after using the bathroom: Do things feel like a slip-n-slide down there? Is there fluid on the toilet paper after wiping?
Many people prefer checking fluid by swiping fingers across the vaginal opening rather than checking internally. Regardless of your personal preferences, checking multiple times per day is very important to get an accurate representation. The way you check is all a matter of personal preference!
Identifying peak day may sound like a challenging undertaking if you’re just starting off with charting. For those who are new to charting, it’s always a good idea to simply observe fertility signs for at least a full cycle (or longer for those in special circumstances like perimenopause or recent cessation of hormone use) to allow individual patterns to emerge.
Peak day, as I have mentioned, is defined as the last day of slippery cervical fluid or wet vaginal sensation. It is not necessarily the day with the largest quantity of cervical fluid, which is a common cause for confusion. The day after peak day, a drying pattern will begin. The peak day can only be identified on the following day. I want to mention that not everyone will experience a “dry” luteal phase. During the luteal phase, some experience a thicker, drier fluid than they experienced during the fertile window, but it may not necessarily be completely “dry.” As with basal body temperature, it’s imperative to look at the overall cervical fluid pattern rather than honing in on the individual day. Focusing on changes in fluid from day to day will eliminate a great deal of confusion and uncertainty.
During daily checks, it may even be helpful to snap a picture of your cervical fluid with your phone. This may make it easier to spot changes. As a learning tool, I have provided a full cycle of cervical fluid images. Each person will find that they have a different fluid pattern, but these images will give you an idea of how cervical fluid can change throughout the course of a cycle.
Even though many people who practice STM don’t rely on cervical position to determine fertility, it’s a great way to confirm other fertility signs. The first question you should ask yourself when checking cervical position is can I even feel my cervix? Is it sitting low in the vagina, or does it seem to have retracted up into your stomach? If the cervix is particularly high, it will be easiest to reach in a squatting position or while sitting on the toilet.
The first thing to note about cervical position is the softness or firmness of the cervix. Does it feel firm like the tip of your nose, or soft and fleshy like your lips? Is the opening closed tightly, or does it feel slightly open? Those who have given birth vaginally will always have a cervix that may feel slightly open, but changes in the firmness, height, and openness should still be evident as ovulation approaches.
When the cervix feels especially firm, it will also generally be low in the vagina and tightly closed (unless you have given birth vaginally). A low, firm, and closed cervix will usually be coupled with “dry” cervical fluid—or sticky fluid, if you do not have a “dry” basic infertile pattern (BIP). As estrogen levels rise, the cervix will begin to soften, rise, and open; at this point it will begin to produce sticky or creamy fluid. At its softest, highest, and most open position, it will produce mostly slippery, fertile fluid (which, remember, can mean slippery, clear, and stretchy fluid or slippery, thin, and watery fluid); these are the most fertile days and generally indicate that ovulation isn’t far off. The only time the cervix may be both firm and open (if you have not had a vaginal birth) will be during menstruation, as the os opens to allow menstrual flow pass through. However, this does not indicate fertility.
Becoming a professional cervix-checker isn’t something that happens right away; it takes some time to become familiar with your body’s individual patterns. This fertility sign may not be necessary to determine fertility, but it can help uncover possible health problems. For example, if you suddenly notice bumps or swelling of the cervix that does not go away on its own, it might be time to see a doctor. But if you don’t take the plunge (pun intended), then you’ll never reap the benefits.