Your Podcast Host:
Lisa Hendrickson-Jack is a certified fertility awareness educator and holistic reproductive health practitioner with over 20 years of experience teaching fertility awareness and menstrual cycle literacy. She is the author and co-author of two widely referenced resources in the field of fertility awareness and menstrual health — The Fifth Vital Sign(opens in new tab) and Real Food for Fertility(opens in new tab) — and the host of the long-running Fertility Friday Podcast(opens in new tab). As the founder of the Fertility Awareness Institute(opens in new tab), Lisa’s current clinical focus is her Fertility Awareness Mastery Mentorship(opens in new tab)TM Certification program for women’s health professionals.
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Episode Summary: What TTC Women Really Know About Their Fertile Window
In this episode, Lisa breaks down the findings of a large-scale study examining fertile window awareness among nearly 98,000 women actively trying to conceive in the United Kingdom. The data reveals that approximately 41% of these women could not correctly identify their fertile window, with knowledge gaps appearing even among those who described their cycles as “regular.” Lisa discusses how cycle length awareness, duration of trying to conceive, cycle regularity, and prior pregnancy history all appeared to be associated with differences in fertile window knowledge across the study population. She also highlights disparities in awareness among women with irregular cycles and differences observed across ethnic groups. Throughout the episode, Lisa connects these findings back to the practical value of cycle charting, emphasizing why tracking — rather than assumption — may help women and practitioners get a clearer picture of ovulation timing.
Listener Takeaways for Understanding Fertile Window Awareness
- A large-scale study of nearly 98,000 women trying to conceive found that a significant portion could not identify their fertile window, offering insight into how common this knowledge gap may be.
- Describing a cycle as “regular” does not necessarily correlate with knowing one’s own cycle length or fertile window, according to the study’s findings.
- Research cited in this episode suggests that the length of time a woman has been trying to conceive does not consistently predict greater fertile window knowledge.
- The belief that ovulation always occurs on day 14 of a cycle is a common assumption that may not reflect actual ovulation timing for many women.
- According to the study, women with irregular cycles showed lower rates of fertile window awareness compared to women with regular cycles.
- Prior pregnancy was associated with greater fertile window awareness in the study population, highlighting a potential link between lived experience and cycle knowledge.
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Full Transcript: Episode 641
Lisa Hendrickson-Jack: This is the Fertility Friday Podcast, episode number 641.
In today’s episode, we are diving into an important topic, which is: How well do women really understand their fertile window? Of course, if you are in this field, if you’re listening to this podcast, then you probably have a much greater understanding of your fertile window and just the fertility awareness method, or even just the concept of cycle tracking, understanding ovulation and being able to know when it’s happening or how to confirm it. You would have a much greater understanding than the general population and likely far better than your clients as well. But what I’m going to be doing today is going into a fairly recent study that actually examined this on a pretty large scale.
This study examined just under 98,000 women who were trying to conceive. Whenever there are studies that are looking at the level of fertility awareness knowledge of women who are actively trying to conceive, we would assume that of anybody, these women who are actively trying to conceive would have better knowledge than the general population. That is just an interesting note as a starting off point of thinking how the average woman who’s trying to conceive is thinking about her cycle and how important that is.
From the perspective of fertility awareness, understanding ovulation feels pretty central to me, pretty mandatory information to actually understand when you’re ovulating to be able to time sex correctly if you’re trying to conceive. But for those of you who are working with clients, who are practitioners, I think that this study also gives us a significant amount of insight in terms of: What does my average client know about charting and timing, even if she sounds really confident? We’re going to go through some of these findings. I would say that very few of the findings actually surprised me, but it is really helpful to actually have data at this scale to be able to get more insight into what our clients really know about their fertility.
Even our fertility clients who’ve been trying for a while, I think that sometimes we may overestimate how much they know. Let’s get into some of the key findings, because I do think it is ultimately fascinating.
A little bit of information about this study: I mentioned that they surveyed just under 98,000 women. These were women who were trying to conceive. There essentially is a website that was surveying women who were seeking information about fertility, who indicated that they were actively trying to conceive. This population was women from the United Kingdom, and they had a variety of questions that they had these women go through that would indicate their general level of knowledge about a variety of different topics related to their menstrual cycles and fertility.
One of the reasons why I chose to talk about this study is because this study was specifically asking questions about their knowledge of their cycle and ovulation and timing and things like that. And not all studies that are looking at just the general topic of fertility awareness — fertility awareness is a phrase that has a lot of different connotations. Generally in the research, when you see a study on fertility awareness, like the awareness of fertility, these are often studies that are asking women a variety of questions to ascertain their knowledge about their own fertility in various ways. And not all studies that look at this general concept of fertility awareness among women who are trying to conceive, or in general, are actually asking very detailed questions about the menstrual cycle timing sex. They may even be just asking general questions about are you aware of how age impacts fertility, or something like that.
What stood out to me about this study was that they were specifically asking questions about the cycle to determine how well these women understood their cycles and timing. Because obviously that has a significant effect on your likelihood of conception if you have a really significant misunderstanding about when to time sex correctly, and that is just being done over and over and over again, meaning that you’re timing sex at the wrong time all the time.
I think the big headline from the study is that about 41% of this population, just under 98,000 women who were actively trying to conceive, could not identify their fertile window. If we break that down further, about 13% completely just said, no, I have no idea. And then about 28% said that they were unsure.
Let’s get into some of the key points to go into the weeds a little bit more about this data. But if you think about that — it’s almost 100,000 women in the UK who are actively trying to conceive, and 41% specifically are saying that they don’t really know and aren’t really sure about their fertile window. This really does reflect all the things that we talk about all the time. We are not taught much about our cycles at all. The knowledge about cycle tracking and even understanding the cycle at a more granular level is not even taught to most health professionals, right? This does reflect, obviously, the situation.
This was the largest study ever conducted on fertile window knowledge in women actively trying to conceive. I am impressed by the sheer number of women that participated in this study. This also shows us how crucial it is that women’s health practitioners uplevel their own knowledge. First of all, we know that we can’t assume that just because you are working with a practitioner who specializes in fertility, that means by definition that they also understand how the menstrual cycle works. Because again, this is a huge piece that is missing from our education system.
This study shows you, even if you’re working in fertility all the time and you’re working with women who are actively trying to conceive in whatever capacity, if that is your client base, most of these women don’t necessarily know. Some of these women outright said, no, I don’t know. But then there’s also the subpopulation of women who said, yeah, sure, I understand it, but in practice don’t actually know the specifics of it.
Another interesting stat from the study was about 17% of women who were actively trying to conceive didn’t even know the length of their own cycles. I think that is interesting. There were about 60,000 women who described their cycles as regular. In the survey, they were saying, are your cycles regular? And they would have defined what that means. Out of that 60,000 who said, yes, my cycle is regular, 10% of them didn’t even know the length of their own cycle. There were also a small percentage of women who said that their cycles were normal, but their cycles actually weren’t normal.
This is something that we talk about with our practitioners all the time in our FAM program, which is that it’s like trust, but verify. If you’re working with clients and they’re telling you, yeah, I always, I’m like clockwork, every cycle is always 28 days, whatever — I’ll listen and I’ll smile and I’ll take a note. But what I really want is for you to track your cycle so we can see what’s really going on. Because when you’re not tracking it, then you may be under the assumption that it’s always the same, but it only takes two or three months of tracking to see that every cycle is not going to be the same length. And in any given year, you’re going to have a couple of outlier cycles where your cycles are a little bit longer or shorter, because we’re not robots, we’re human beings, and our cycles are a vital sign that they’re constantly reflecting what’s happening.
I feel like the data reflects what we actually see as practitioners when we are listening to what our clients are saying, but comparing it against what’s actually happening in their cycles. When we put that data together, approximately 13% of the women who said their cycles were regular either didn’t know their cycle length or were actually wrong, because their cycles actually weren’t regular, and what they were thinking wasn’t matching with what they were actually noting down.
I think from that key data point from the study, what we can take from that as practitioners, if you’re working with women, fertility clients, all of that — we really have to move beyond what our clients are saying about their cycle and just get a better understanding based on the data itself about what’s actually going on. And we do that by, of course, having our clients track their cycles.
This other point was not surprising, but I think depending on how you think about it, it could be. The researchers found that the longer that a woman was trying to conceive, it actually predicted that she had worse knowledge, not better. I feel like logically you would think the longer someone’s trying, the more likely they would figure it out and they would know. But of course, this is kind of like that chicken or the egg question. Is it taking longer because they don’t know the true ovulation date, and that is one of the factors that is causing it to take longer for them? Or is it just taking longer because there’s actually an underlying issue?
The interesting thing from the perspective of having your clients chart their cycles and having an ability to actually identify — if they’re ovulating, if they’re ovulating normally, if the cycle, even if the cycle is irregular, even if the cycles are very long, you can still identify if your clients are ovulating or if they’re ovulating normally, if there’s any general issues from just having them track. I think this also shows that there is a percentage of couples who are trying to conceive who literally, if we just get the timing right, then that will help them to sort this out.
I think the longer that a couple is trying, you would think, okay, well, they must be hitting it at some point. There’s more likely to be an underlying issue, which I do think is correct. But women who were trying to conceive for a year or more were actually less likely to know their fertile window than women who were trying to conceive for under a year. It was a bit of a subtle difference — about 54% of women who were trying to conceive for more than a year knew their fertile window, compared to about 63% who were trying for less than a year who knew. So it wasn’t this huge gap, but on the other hand, it does give you pause. At least it gives me pause.
For practitioners who are working in the field with women who are trying to conceive, when you have a client in front of you who’s been trying to conceive for a long time and she’s telling you, “I understand my cycle” and all those things — it’s possible that she does, obviously. But we want to look at that data and make sure that she’s really, really clear on that.
One of the classic examples that I share, and I think this is super common if you’re working with women in this area, then you’d see this kind of thing too — obviously we have been trained to believe that cycles are 28 days and ovulation happens on day 14. That is a model, and so we have been trained in that. When I’ve been working with clients, many clients are trying to have sex specifically on day 14 of their cycle. They’re using their ovulation strips around that day. And depending on how long they’ve been trying, maybe they’re not necessarily having sex all the time — they might have sex once or twice per cycle, and that once or twice is hitting that day 14.
Based on a variety of different studies who’ve looked at this, the percentage of women who ovulate specifically on day 14 can be as low as 13 to 15%. Even just that mindset of “I’m going to try on this day and my cycles are normal or whatever,” then that would indicate that there is a percentage of women who’ve been trying to conceive for a while who are likely mistiming, because they are basing it on this idea of day 14. That’s just one example of how, if you were mistiming and that was a consistent habit, that could interfere with your chances of conception, theoretically.
From the practitioner’s standpoint, when you’re working with clients who’ve been trying to conceive, especially clients who’ve been trying to conceive for quite a bit longer, we can’t just assume that they have a better understanding. We have to make sure that we evaluate that and identify what’s really going on.
This kind of leads me to a really interesting data point that the study found. When they compared the fertility knowledge of women with regular cycles versus irregular, only about 27% of women whose cycles were irregular — so met the definition of longer than 35 days or variation of more than eight days from cycle to cycle — about 27% of women with irregular cycles actually knew and could identify their fertile window based on their responses, versus about 74% of women with regular cycles.
In all fairness, if we’re not taught anything about our cycles, and we’re not taught that ovulation doesn’t always happen on day 14, and the pre-ovulatory phase is actually the most variable in the cycle, it makes sense that if your cycles are regular, you’re going to be less likely to figure it out. Because based on what are you figuring it out, unless you understand mucus, unless you understand cycle variation and the luteal phase and how all of that works, then you would be less likely to understand when you’re ovulating. It would just feel like, I just don’t know when my period’s coming, I don’t know how long my cycle is going to be this month, it’s always different. And so, of course, it would be a lot harder to figure this out.
I think this is why one of the biggest myths around irregular cycles is that if your cycles are irregular, you won’t be able to get pregnant, or “am I ovulating,” whatever. But obviously the great thing about cycle charting is that it allows you to figure out that answer. Even if your cycles are irregular, you can still identify ovulation and time sex correctly.
This is a huge opportunity, again, for practitioners to jump in, especially if you’re working with clients with irregular cycles, because they were far less likely to understand their fertile window. This is just based on a survey, so I would love to take that even further and see: okay, so they’re saying they understand their fertile window, but if their cycles are irregular, does that match up to — are they charting? Are they tracking? And how are they identifying and confirming ovulation?
To put that stat in another way, women with irregular cycles were eight times less likely to know their fertile window. Women who are cycling and their cycles are not regular, they’re falling outside of the normal parameters — they’re the ones that need this knowledge in a sense the most. But with that said, there was still just a little bit over 25% of women with regular cycles who still didn’t know. So that is something to consider.
There was another interesting finding when they compared black women to white women in the study. They did find that black women overall, compared to not just white women but other races as well, had the lowest fertile window awareness of any ethnic group. There was just about 50% of black women who said that they did not know their fertile window. That’s also an opportunity for practitioners not to make assumptions that just because of a person’s skin color they don’t understand anything, but to be aware that there is, according to the study of nearly 100,000 women, even less knowledge within the Black community. I think that is another really interesting stat that can give us pause.
What I would say overall is that this study does show us and confirm that there is a significant gap in knowledge. We know this already, but this study further gives us the data to show that the average woman is really not that informed about her cycle length overall. Because again, this study is looking at the population that would be most likely to know. Women who are actively trying to conceive are highly invested in getting pregnant. That’s the whole purpose, right, of trying to get pregnant. You would think that these would be the women who would have the most knowledge.
If you expand that out to women who are not trying to conceive, women who maybe pregnancy isn’t exactly on the radar, it would be really interesting to see a study of that nature. But I think for the practicality of researching a topic like fertility awareness, obviously it makes more sense that the population was actively seeking information about fertility and conception, given that they were trying to conceive. It makes a lot more sense that we’re going to be serving these populations. But if anything, if the study is showing us the limited knowledge within this population of women who are actively trying to conceive — a significant percentage of those women who had been actively trying to conceive for over a year — if these women don’t have a solid, firm knowledge of their fertility, then what would that say about the average woman?
I stick to that point. This study is particularly interesting to me when we think about it from the perspective of practitioners who are actively working with the fertility population. This is our opportunity. This is really one of the missing pieces that would help our clients so much. One of the foundational beliefs and parts of our training in our Fertility Awareness Mastery Mentorship Program is to really try to identify the foundations before assuming there’s a problem. We really want to put everyone on the same playing field. If we elevate the knowledge of our clients so that they can understand how to identify ovulation, how to even confirm if they are ovulating, and how to time sex at the correct time of the cycle — because based on what the research tells us, there’s about a six day window, the five days before ovulation and ovulation day.
If we can at least level the playing field so that we have our clients who are trying to conceive, trying at the right time and confidently so, with evidence, right, with the charts, with the data to support it — not just based on, oh, I think it’s day 14 or whatever, but actually based on actual biometric data, the fertile signs, cervical fluid. We can use ovulation strips, but we can use cervical fluid, we can use basal body temperature to confirm that ovulation has occurred and all these things.
If we put everyone on the same playing field, then there is going to be a percentage of women who are trying to get pregnant who will conceive just based on that. That allows us to separate those who just had a timing issue and those who have deeper issues at play.
The last thing I’d like to close on is just to kind of point out that within every population, there are also women who think that they know, but really, if you put their knowledge to the test and actually have them chart and identify, there is a mismatch between when they think they’re fertile and when they’re not. I would say the same thing could apply to practitioners. There certainly is an argument to be made for a more in-depth knowledge of the fertile window as just a standard part of any practitioner-client relationship, especially when your client is trying to conceive.
One more stat that I found interesting: while women who were trying to conceive longer compared to women who were trying to conceive for less time — the year versus under a year versus over a year — the women who were trying to conceive for over a year didn’t necessarily have more knowledge. There was one group of women who did consistently have more knowledge of their fertile window compared to the others, and those were women who had actually been pregnant before.
Again, one of the interesting findings of the study was that women who had successfully conceived previously and were trying to conceive again overall generally had a greater degree of knowledge about their fertile window and things like that. I feel like that actually does make sense. But we shouldn’t have to have gotten pregnant already to understand our fertility. Practitioners, this is your opportunity. I hope that the data and findings from the study have just helped to kind of enlighten you and attune you to the importance of ensuring that you are grounding your clients, your fertility clients, in solid fertility awareness teaching, which is of course what we do in our Fertility Awareness Mastery Mentorship program.
I hope that you enjoyed today’s episode. If this episode resonated with you, feel free to share with a friend. You can head over to fertilityfriday.com — today’s episode is 641. And if you’re listening in your favorite podcast player, you can also use the share link there. I hope you have a great week, weekend, or whenever you’re tuning into the show. And of course, as always, until next time, be well and happy charting.
Peer-Reviewed Research & Resources Mentioned
- Fertility Awareness In 97,414 Women Trying To Conceive: Gaps, Misconceptions, And Implications For Reproductive Education
- The Fifth Vital Sign (free chapter!)
- Real Food for Fertility (free chapter!)
- Fertility Awareness Mastery Mentorship (FAMM)
- How to Interpret Virtually Any Chart — For Practitioners! (complimentary eBook)





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