Cervical Mucus and the Fertile Window: When to Have Sex to Conceive (Episode 538)

Full Transcript: Episode 538

Lisa Hendrickson-Jack:

In today’s episode we are going to talk all about when is the best time to have sex when you’re trying to conceive. When it comes to fertility awareness-based methods, I often say that we really should be paying attention to mucus as the primary sign of fertility when we’re trying to conceive. And the other signs that we may be tracking, whether it be basal body temperature or even an ovulation prediction device, those should come secondary to mucus. So in today’s episode, we are diving into a study that looks at mucus specifically and its validity in identifying the fertile window and also its impact on pregnancy rates and time to pregnancy.

So without further ado, let’s go ahead and jump right in.

So the title of today’s research article — Stratification of Fertility Potential According to Cervical Mucus Symptoms. So as the title indicates, it really zones in on cervical mucus specifically. And they actually are looking specifically at the Billings ovulation method, which is one of the mucus-only methods of fertility awareness charting. And they’re looking at how identifying that fertile window with the mucus sign only — what effect that has on fertility and pregnancy.

So it’s a really, really interesting study. So a little bit of background information in the study. They had a sample size of 384 participants who were desiring to achieve pregnancy. So in this sample, these participants were specifically trying to conceive — some of whom had been trying to conceive for some time and others potentially just starting out trying. And they had them keep a record — a daily record of their cervical mucus observations through the lens of the Billings method. So the Billings method uses a combination of what they call vulva sensation and as well as visible observation. So a little bit different to the method that we teach our FAM practitioners, but ultimately it is very similar in the most general sense, because it is identifying those days of fertility specifically based on the mucus sign only.

So for those of you who have listened to the podcast for a while, or for those of you who are familiar with fertility awareness-based methods, you’ll know how essential cervical mucus is to identifying the window, what a crucial role it plays, especially for women who are trying to conceive. And there’s a number of different reasons for that. One of the reasons is strictly timing. When we can identify the days of fertility based on cervical fluid — versus the days where we’re not seeing any cervical fluid observations — that is telling us that our cervix is open. When we learn a little bit about the biology of our cervix, our reproductive tract, and the scientific knowledge behind the actual method of fertility awareness charting, then we learn that the cervix is actually closed most of the time throughout the menstrual cycle. It is plugged with a thick mucus plug outside of our fertile window that does not permit sperm or bacteria or any other kind of invaders to get anywhere near our reproductive tract — so anywhere near our fallopian tubes or the ovaries. And so when we can identify those days of cervical fluid leading up to ovulation, that is telling us that the cervix is actually open. So in terms of timing, that is one of the most crucial pieces of it.

In addition to timing, cervical mucus also creates a wonderful environment for sperm. I’ll often say that it’s like a home away from home. And if you compare, say, the pH level and kind of overall environment of our cervical fluid, it is very complementary to a man’s seminal fluid. So quite literally, home away from home, if you will.

So that’s a little bit of background. And it’s interesting because once you start charting your cycles, this information can feel just so easy, so simple, because after you learn it, it just does feel so intuitive. And when you start paying attention to your cervical fluid throughout the menstrual cycle, and you start to notice this pattern where as you approach ovulation, you actually see this fluid — you feel potentially like wet down there. You’ll notice that it’s, you know, when you’re wiping, it’s really slippery. You’ll notice maybe some discharge on your underwear. And now that you know what it is, it’s like, “Oh my gosh, of course that’s what it is.” But when you didn’t know — so for those of you who learned fertility awareness but there was a time when you didn’t know — you can look back and you had no idea. I can look back from when I was a teenager and I had no idea that it was linked to fertility, to ovulation, to my menstrual cycle. I just knew that there were some days when I was wet and there were other days that I wasn’t, and I had no idea why.

So a few more details about the fertile window itself. When we look at what the research has to say about the fertile window, the fertile window is typically defined as a six-day period of time — the five days leading up to ovulation plus ovulation day itself. And there’s numerous studies that show that pregnancy results from unprotected sexual intercourse during that six-day period. And outside of that six-day period, pregnancy doesn’t really happen because that is truly the fertile window. So when we’re able to pay attention to that cervical mucus sign and we’re able to identify those days of mucus leading up to ovulation, we are really able to zone in on that six-day window where it actually counts.

I’ll also mention that when you’re tracking cervical fluid, each method might describe the different types of mucus with different words or in a slightly different way. But generally speaking, what women will observe is sometimes you’ll observe like a lotiony type discharge — the best way to describe it is like white creamy hand lotion. And at other times, women will observe that clear kind of like raw egg white stretchy cervical fluid. And if you were to pick it up and stretch it, it will typically form a thread between your fingers. And then at other times, it might be too watery to actually pick up, but you would wipe and feel a really lubricative sensation. So in the method of charting that I teach, we distinguish between those two main types of mucus — the clear, stretchy, lubricative type mucus we call peak mucus, and then the lotiony mucus we call non-peak mucus.

In all fertility awareness-based methods that teach mucus, they typically teach women how to identify between these types of mucus. And although pregnancy is possible on any day of cervical fluid leading up to ovulation regardless of type, when we’re looking to optimize chances of conception, we do want to prioritize the days where you have that clear, stretchy cervical fluid — and in particular, the days that you have it in the highest quantities. That’s not because pregnancy can’t happen on the other days. It’s not to say that you are less fertile. But on those days where you have the clear and stretchy type of cervical fluid in the greatest quantities, that is typically associated with the highest levels of estrogen, which puts us closer to ovulation.

Now, before I get into the results from the study, I think one thing that’s really interesting just to put it back into perspective — there’s a study on fertility awareness knowledge among women seeking fertility assistance. And this study was done by Dr. Kerry Hampton — I had her on the podcast many years ago — and in that study she found that only about 12.7% of women could accurately identify their fertile window. So they had a group of women, and they felt quite confident in their ability to identify their fertile window, but when it was actually put to the test, very few of them were actually doing it right.

So for those of you who’ve been longtime listeners or those of you who’ve been charting your menstrual cycle for a long time, it can seem like this easy thing that everyone should know. But we represent a very small percentage of the population — those who are actually aware and practicing fertility awareness-based methods. And also for the women’s health practitioners who are listening: if you are a women’s health practitioner, not only do your clients not have this information, but most practitioners don’t have this information either, regardless of the profession. Whether we’re talking about medical doctors, naturopathic doctors, nutritionists, even women’s health coaches — most women’s health practitioners don’t necessarily have this knowledge. And that’s because it’s not really a standard part of most trainings whatsoever.

So what happens when we are given this information?

So I’ll read this piece from the study because I feel like this also helps us get into the results. What the researchers said is: the major finding from this data is that the identification of fertile and infertile mucus patterns is a powerful predictor of successful conception. The researchers found a statistically significant benefit — so once these couples were taught how to identify their fertile days based on cervical mucus, the pregnancy rates as well as time to conception improved significantly. They found that once they taught the couples how to identify their fertile days based on mucus, that knowledge and the change in behavior that resulted was associated with an approximately 30% increase in pregnancy rates in the study. And they did note that the quality of mucus was related to the time to pregnancy and also the overall chance of pregnancy — women with optimal mucus patterns tended to conceive more rapidly, and there was a higher percentage of women with more optimal cervical fluid observations who conceived within the time frame of the study.

If you want the data — women who had those peak mucus symptoms, or higher rates of it, on average conceived within about 4.2 months versus the women whose mucus observations were a bit less optimal, who took on average about six months. So a pretty significant difference based on the quality of mucus alone being the main differentiator. Another interesting stat was that the majority of the women who conceived in the study — about 77% — conceived within the first six months, and 92% conceived within the first 12 months.

So what do we do with this information? I think the biggest takeaway is that as simple as it sounds to those of us who’ve been charting our cycles, it is the key. And one of the things that I always talk about with our FAM practitioners is to support our clients to get out of that rhythm method thinking. So many women — even those who chart their cycles — are still often thinking in terms of the date. “I usually ovulate on day 14. I usually ovulate on day 15.” And so they’re often making decisions and making judgments based on that date — not always thinking primarily of mucus.

One example: if you happen to start observing mucus earlier in your cycle — so you start to see mucus right after your period is done — I think there are many women who are in that rhythm method thinking and will be more likely to kind of ignore what they’re seeing and think to themselves, “Oh, it’s too early.” And so even if they’re trying to conceive, they might not have sex on those days that are optimal for conception. And on the flip side, if you’re expecting to ovulate around day 14, and maybe you even do see a little bit of mucus along the way, you might just assume that you did ovulate and then just stop tracking. Your mucus could come back a few days later because you didn’t ovulate in this example, and then you ovulate later on — but you could completely miss it just because you’re not looking for it.

This is one of the reasons why studies like this one show an improvement in pregnancy rates — because when you teach a couple how to identify that fertile window and you tell them that those days of mucus are the days that they should be having sex on when they’re trying to conceive, it makes a huge difference. And for many couples, that one change is enough to get things rolling and for conception to happen.

Now on the flip side, there are couples who do know this information and who are tracking. If you have couples who are timing sex correctly, then that typical advice of “wait a year before you get a fertility assessment” — I feel like that doesn’t exactly apply. Because when you have a couple who’s specifically timing sex correctly — not just in their head correctly, we can look at the chart — we can see that they’re timing sex on those days of mucus leading up to ovulation, we can see ovulation confirmed through the temperature shift and the mucus drying up. So we know that timing is correct. There are a number of studies that suggest that if we are timing sex correctly — they usually refer to that as fertility-focused intercourse — then we could truncate that usual suggestion of a year to six months. Because if pregnancy isn’t happening within that first six months, then we may need to be looking at other things.

So timing is essential because if timing is not correct, you can’t get pregnant. But timing is not everything. We need to get the timing right, but that doesn’t mean that timing it correctly is just going to solve all the problems. One of the things that I always bring up is sperm quality — we always need to be looking at that. We need to investigate men just the same way that we would investigate women when we have concerns about fertility challenges.

One of the conclusions that the researchers made was how helpful this approach can be overall, because it provides a targeted, specific, tailored approach based on what’s happening with the couple. As a first port of call, before jumping to tens of thousands of dollars for fertility treatments, it is useful to chart. And from my perspective, when we get into the conversation about using the menstrual cycle as a vital sign, in addition to timing, we also want to track a woman’s fertile signs to determine if her cycle is normal — if she’s falling into normal parameters, if her mucus patterns are normal. Because in the study they did show that women who had mucus patterns that were not optimal did tend toward a longer time to conception.

If we’re able to chart the cycle and identify if her parameters are normal — parameters including overall cycle length, mucus quality and quantity, whether her period is falling into normal parameters, when ovulation is taking place in the cycle (between days 10 and 22 approximately for a cycle somewhere between 24 to 35 days), and the post-ovulatory phase to see if it’s long enough or if there are signs potentially of low progesterone or other hormone imbalances — there is a lot of information we can glean from the cycle. And if you have a client whose cycle is pretty good and is falling into normal parameters but pregnancy isn’t happening, that’s also a good flag to look at him and ensure that his sperm quality is being assessed.

Lots of great takeaways from this research study. I hope that you enjoyed today’s episode.