Fertility Rules from wildfire sperm death and microplastics to the potential of AI with investor Leslie Schrock

Danny Crichton:
Hello and welcome to Securities, a newsletter and podcast devoted to science, technology, finance, and the human condition. I'm Danny Crichton, and today we have a special guest, Leslie Schrock, the author of Fertility Rules: The Definitive Guide to Male and Female Reproductive Health. Leslie, thank you for joining us.

Leslie Schrock:
Thank you so much for having me and for doing such a lovely introduction.

Danny Crichton:
Well, thank you. So Leslie, this is your second book on pregnancy and fertility. The last one was Bumpin', and I'm curious, how did you first get into this whole concept? Because when we think about fertility, it's something that most people want to avoid. No one wants to talk about it. Even our schools don't want to talk about it, and yet every single person is affected by it. So what was your journey into this subject?

Leslie Schrock:
I've worked in the digital health space as an investor, advisor, and an entrepreneur for over 10 years. So I was on the founding team at Rock Health. I was a fairly early advisor to Maven. I'm still an advisor to actually several of the Lux portfolio companies, Alife, Gameto, and Maven, obviously. And during that experience, I came up, as so many of us do, assuming that when I was ready to start a family, no problem. It was going to be easy. I was in my mid-thirties, I thought, "Yeah, I'm healthy. It's going to be fine. I'll just get pregnant on the timeline that I want." Little did I know I was going to have a very difficult personal journey ahead. So in the end, I had three pregnancy losses. The first was a miscarriage. The second actually ended with a medically necessary abortion, which really was the impetus to me writing my first book, because what I realized is that even though I was surrounded by all of the resources and all of these professional folks in my network who could help me through this, no one had shared that experience with me.

I had no one to talk to. So I felt like miscarriage especially was kind of the gateway for me as an issue that is incredibly common. It happens in as many one in four pregnancies, we think, and yet no one was really talking about it at the time. So I wrote Bumpin' in real time when I was pregnant with my first son, which was quite an adventure, as you can imagine. Simon & Schuster is still my publisher now. They let me do that, which was kind of crazy. The postpartum section was written postpartum. But in the end, what I realized was that I had gone through, in the end, three failed pregnancies, and there was so much that I wish that I had known before I had tried to start a family. So that was the path that led me to writing Fertility Rules, my now second book, which answers the question, if you're thinking about trying to conceive, what should you know and what should you do? And are fertility cleanses really a thing or not? And the answer is no. There's just so much crap out there, right?

Danny Crichton:
Right. Well, I think a huge part of about the book ... so I read the book and there's two types of thoughts. First was the number of myths. There's just an incredible amount of misinformation that's out there. A shockingly high number. I mean we're in a world of COVID misinformation, vaccine misinformation, but what I was surprised by is how little we've actually discussed the fertility misinformation. And the second piece was the amount of planning that goes into here, both on testing, on fertility treatments, on the different options and pathways you can take, because in my view, it is sort of the textbook seventh grade, which we all sort of got, which was a banana, a condom, and some gel -

Leslie Schrock:
And a school nurse. It's all awkward.

Danny Crichton:
Yeah, a school nurse. And it's awkward. And that's your only education. And it opened my mind to there are dozens of tests, there are dozens of procedures, you have dozens of different pregnancy blockage devices or whatever the case may be. How do you sort of grapple with that complexity in those myths today? Because it's gone from something, in my view, so simple, to something so complicated.

Leslie Schrock:
Yeah, I mean I think that one big reason that all of this is more complicated is the average age of first time parents is creeping up, up, up, up, up. It used to be mid-twenties, then it was the late twenties. Now in coastal cities it's more like 32 or 33. And the reality is that for men and women, your body just isn't as good at producing sperm and eggs as you age due to issues during myosis for women, that's the process of eggs maturing. And there's nothing you can do about it. There's nothing. There's no pill. Maybe Gameto's going to solve this problem for us. I'm hoping that they do, but the reality is it's not a problem that can just be solved with technology today. You can do assisted reproduction treatments, you can freeze eggs, but there's no guarantee of anything even when you freeze eggs today.

So I think that really that is what's starting ... that is really what's created the world that we live in today largely. The other is the exposure to endocrine disrupting chemicals, which maybe we'll get into a little bit, but we live in a much more complex world now. We're exposed to a lot. We are working harder than ever in a lot of ways. We are also more sedentary than ever. And also our food sources. And this is something that was important for me to dig into in the book because I think that for most of us, when we engage with the healthcare system, these are not conversations we're having with our doctors. We are not talking to them about our diets. And the truth is doctors aren't trained in nutrition. They get about 20 hours on average of training during medical school. Four years, that's it, including fellowships. Even if you are undergoing fertility treatments, odds are your doctor's just going to tell you, "Eat well," but what does that actually mean?

So I think my goal was to wrap this very basic knowledge that none of us really got as kids, the menstrual cycle, basics of sperm health, hormones, all of it, and really try to reboot the conversation, because I think it's kind of crazy that men and women don't learn about each other's bodies. Why do we have this bifurcated experience as kids, where girls are sent off to a room where they're kind of whispering about their periods, and then boys are sent to a room and Lord knows what they're learning. They know ... I mean, listen, men know even less about their reproductive health than women. It's a travesty. They're not taught as kids. I don't even blame men for the lack of knowledge. Many people do. I don't. I think men want to be better allies, they want to be better partners, they want to be better parents. They simply are never given the information, they do not get it in doctor's appointments, and thus, where are we? So I think if we lived in a world where men and women understood fertile windows, for example, the period in which you can actually get a woman pregnant, from the time that they're kids, a lot of the problems we have today would not exist.

Danny Crichton:
When we think about a lot of the myths, so to me, there's a huge amount of information that you have in the book that everyone should know. There's information on sperm counts, on general health, the need to use a doctor and a GP effectively. And you have these striking statistics where it's like men don't go to their GPs, they don't get physicals. When they go to the physicals, they don't get checked for any of this sort of stuff. There's almost no sperm testing in general for men as part of a standard practice of care. So you're not looking at sperm motility, you're not looking at the sperm counts. They're only done in academic studies. And that's actually what I thought was interesting, is you actually created a system where you're saying, "Look, it's not just about fertility. All this is interconnected with general health."

Sperm counts for men, and similarly for women connect into the general wellness. So if you're eating well, if you're working out, if you have a good lifestyle, if you're not sedentary, if you're not drinking or smoking or using cannabis, all these numbers look better, as do almost all the other biomarkers that are at the core of your health. And you actually position this as not just like if you need children, you should go do these tests, but really this should be part of a general purpose exam that is also informing the rest of your health in general.

Leslie Schrock:
Absolutely. I mean, if we could just get guys to do a semen analysis from home, that's such a big step forward in just managing men's health in general, because as you just explained, men are terrible utilizers of the healthcare system. They might control it at the upper levels, but they certainly don't interact with it. How many men do you know who get a yearly physical or even a physical every two to five years? Not that many. They only interact with the healthcare system when maybe something is about to fall off. And that's not a great place to be, because it's not just about men's health. So semen parameters are really ... they should be considered a biomarker. It is an indicator of a man's overall health. You can tell an awful lot. It can indicate tumors and cancers, all kinds of stuff. If it's not good, odds are something is going on in a man's body.

And the good thing for men is that with three months plus, you can actually turn semen parameters around. So unlike women, who are born with all the eggs they will ever have, men, on the other hand, actually regenerate sperm about every two to three months. So if you, for example, stop using cannabis, if you stop using steroids ... another one that just came up recently for me, which I was kind of mind blown, is these products that help with hair loss are actually also detrimental to sperm health. So all of these things that we're using right to improve men's appearances for aesthetic reasons, actually they should not be using while they're trying to conceive because it adversely affects your sperm parameters.

The other thing is, and this is I think what what's really resonating with women, is that this isn't even just about men's health. This is about future children and it's about women's health. So unhealthy men create all kinds of problems for women, not just from a caregiving perspective, because let's be honest, we're just going to take care of them in old age too, but unhealthy sperm creates unhealthy pregnancies. It increases the risk of gestational diabetes, preeclampsia, preterm birth. It also creates problems for future children. So obese men can pass that onto their kids. Advanced paternal age can drive neurological conditions, it can drive autism. There are all kinds of interesting links that we're just beginning to understand when it comes to the true effects of the state of a man's body when he conceives. Actually, metformin use is another one that's really ... this was a mind-blowing thing.

So a researcher out of Stanford that I've gotten to know, named Mike Eisenberg, did a study last year about metformin use in men and the fact that men who used it three months within trying to conceive a child, those that had a male child were at increased risk of birth defects, genital birth defects. So micro penis, all kinds of stuff, decreased anogenital distance, some things that as a parent you definitely would not want to inflict upon your children. My hope is that men hear this. And if you're not going to do it for yourself, that's fine, don't do it for yourself, but if you care about your future children and you want to have healthy future children, perhaps stopping smoking, THC use, all of the things that we know adversely affect sperm, stop it for your kids.

Danny Crichton:
Right. Well, I think that's the most striking and interesting part of the book, which was obviously fertility is heavily focused on females, but they also have the burden from society, from expectations that it's the eggs that are a problem, it is women's health that's at risk, you have to eat properly during pregnancy, and if you don't, you're harming your own child. But my striking fact was really what you just described, which was, but all the male components here. I mean, ultimately this baby is coming from two parents, a male and a female combining together through sperm and egg, and that is the ingredients that forms a healthy child. So if the male is unhealthy, it's just as much of a risk as if the female is unhealthy and vice versa, which I think is a really fundamental fact that did not show up in any part of education and health in clinical practice that I've ever seen.

Leslie Schrock:
Yeah, I mean you would think it's very obvious, right? I mean it, you can't really ... we have not figured out how to reproduce without sperm yet. So you would think that we would all understand that it's just as important, the state of affairs there, as it is with eggs, but I think that because eggs are so scarce and because we know more about their decline, because the advent of egg freezing, we've just simply done more research, and because they are scarce. You can't regenerate your eggs as an adult. You're born with all you're ever going to have. So I think for men, they assume because there's more of it and because they regenerate it all the time and because we hear these news stories of people like Al Pacino and Robert De Niro who have children into their seventies and eighties, that it's just all fine.

And sometimes it works out, sometimes it doesn't. I think another thing that we're ... this is a major hot button issue for me is ICSI, so intracytoplasmic sperm injection, which is used during IVF cycles to create embryos. And what it is, basically an andrologist, embryologist, whoever is at that clinic doing that job, chooses, looks under the microscope at a sperm sample, semen sample under the microscope, and they choose one sperm based on a visual. So they're using their eyes and a microscope. And as I explain this, you can hear how ludicrous this is, right?

Danny Crichton:
Right. Right.

Leslie Schrock:
They're like, "That one looks good. Let's just load that one up in the micropipette and shoot it into the egg." And we're doing this.

Danny Crichton:
Yes.

Leslie Schrock:
This technology was developed to treat male factor infertility. This was not developed to use de rigueur in every single IVF cycle. It costs patients out of pocket over a thousand dollars on average. It's an add-on, but it's now used in over 80%, perhaps as many as 90%. I'm still waiting on this year's figures actually from the clinical data, but it is being used in almost all IVF cycles now, even if the case is not male factor. And it does not increase live birth rates. That's the worst part. It's the only outcome in IVF that matters. People who love ICSI say, "Well, it increases fertilization rate." That's good. Is making low quality embryos really the goal?

Danny Crichton:
Right.

Leslie Schrock:
You might make more of them, but they might not be good.

Danny Crichton:
Right.

Leslie Schrock:
So I think it's an example of how far we have to go in the fertility industry and some of the baseline issues that we have with it as an business.

Danny Crichton:
Well, I want to get into some of the new products here in just a bit, but before we do that, we started off earlier on talking about environmental toxins, which I think is a big part of the fertility conversation today. Sperm counts are down, eggs are in some case weakened over time from different environmental factors. And we're just starting to learn all the different factors that go into this, everything from microplastics and parabens and a whole list. And you have a whole table of potential threats that makes me want to -

Leslie Schrock:
Many pages.

Danny Crichton:
I love this comment of the burrito is more dangerous than the hamburger, which actually somehow cheese pizza is the best thing you could possibly eat, which I'm totally fine with by the way. I think that's a great policy, just cheese pizza all the time, but let's talk a little bit about the environmental toxins, because that is also a trigger in addition to age and the age in which people are trying to conceive is this sort of increase ambiently in our environments of these toxins.

Leslie Schrock:
So there was a very famous study that was published in 2017 about the temporal trends in sperm. And it indicated that in the last 50 years, sperm counts have gone down. It was just updated in November of last year, because the big knit people had with this study was that it was not reflective of global data. It is reflective now and it shows there is a decline globally. And the leading suspected cause is BPAs and phalates, which are found mostly in foods, plastics, all of the things that we have developed in the past 50 years, funny timing with the study, and we're exposed to constantly. One thing a lot of people don't know is even the dermal, the ink on receipts, that stays on your skin. That can stay on your skin for weeks, being exposed to that. I'm like a tin hat person with receipts now. I just don't even want to touch. I don't even want to touch them.

Danny Crichton:
I'll fight our expense policy on that one.

Leslie Schrock:
Yeah, digital only, please.

Danny Crichton:
Right. Exactly.

Leslie Schrock:
But we are. We're exposed to microplastics in the foods that we eat, the way that foods are packaged, takeout, all of these things. The coating on the inside of takeout containers actually transmits all kinds of weird plastics into the food. So a couple tips that I have for people generally are when it comes to your food at home, try to eat whole foods, organic foods as often as you can, store your foods in glass, and don't microwave plastic. Those are some easy ways to do it, because we're never going to avoid all of it. There is no possible way, unless you live in a cave and don a tin hat, and maybe that's your vibe, but you're not really going to have a real existence that way.

So I think that it's important to know what the worst things are, and that's really what I tried to do with that table. There's a similar table actually in my first book with Bumpin' that has to do with the worst offenders in terms of the things we know cause birth defects and big problems in pregnant, like retinols and salicylic acid and some other things that are found in skincare products mostly, but it is very disturbing. As someone who's been reading and researching this and talking to experts from all walks of clinical practice, researchers, many, many people, and everyone agrees that the world we live in today is just not very well suited for fertility. We were talking about climate change a little bit. I think that that's another.

The rise in heat, not good for sperm. Sperm doesn't like heat. That's the whole problem with external genitalia, I suppose. It's very susceptible to changes in temperature. Sperm counts go down the more heat goes up. So I think it's a problem. Women ... we haven't shown the same impact on eggs yet, but who knows? We don't know. The research hasn't been done, so we just don't even know. Wildfires is another thing. Studies done on firefighters showing the exposure to all of the smoke and particulate matter and everything else. Male firefighters utilize IVF I think something like 10x the rate -

Danny Crichton:
Oh, wow.

Leslie Schrock:
- of a normal person. And the miscarriage rate in female firefighters is very, very high. So we know that in that population, if you're using them as the canary in the coal mine, nothing good is happening.

Danny Crichton:
Well, and that's a huge theory. We call this podcast Securities, but it's this intersection of health security, economic security, social security, national security, all those complicated intertwined pieces. And to me, this is a great example. We have climate change, it's increasing the heat around the world. That's lowering sperm counts in and of itself. And I think your statistic was that over the temperature of 80, sperm counts go down quite significantly at that temperature, so basically just a little bit above room temperature. So just being out in the summer heat.
But on top of that, because of wildfires, we have all this particulate mass coming into the air, just like in New York City just two weeks ago, as we're recording, all these Canadian wildfires coming in from Quebec, blanketing the city with smoke and particulate mass. I have an actual air pollution monitor at my home and it's sealed and it was okay for a couple of hours, but you started to see a tick up as the air was transmitted from inside the house to outside, that we were starting to actually breathe really dangerous air. And that has deep repercussions going in throughout our reproductive systems and bodies, which is a whole nother area, even beyond just lung health, which I think is how that usually gets positioned is like, "Well, you can't breathe as well, but everything else will be fine." It's actually ... there's long-term effects. And once you've had them, in some cases they're permanent.

Leslie Schrock:
Yes. Well, and I mean fertility is one thing, but pregnant women, heat is already a problem because your body is doing some hard work. It's like running a marathon every day being pregnant. And that has impacts on future children too. Exposure to poor quality air can impact a pregnancy, it can impact what happens during that pregnancy, the development of a fetus. So I think we all need to pay attention. It's difficult to give this advice, because most people don't have the option, but if you do live in an area that's particularly fraught with wildfires, you definitely need to keep some N95s around. And if you can leave during a pregnancy or spend time somewhere with clean air ... but again, most of the world does not have that option.

Danny Crichton:
Right. Air filters are expensive, air conditioners are expensive.

Leslie Schrock:
But it's what all the professional organizations say, even though it doesn't really -

Danny Crichton:
Exactly.

Leslie Schrock:
It's like, "Well, how many people can actually do that though? Can we talk about other ways to solve this problem -

Danny Crichton:
Yes.

Leslie Schrock:
- that don't involve physically moving?"

Danny Crichton:
Well, and what was funny was they said the same thing with New York, and I was talking to my husband and I was like, "Well, should we go?" Because I'm looking and the air is getting worse and worse and we're inside. Carbon monoxide's going up. I'm like, "I can't breathe." And then we started to look like, where can we go? And you couldn't go anywhere cause it blanketed the entire eastern United States. They couldn't take off flights from LaGuardia and JFK. So the idea that you can just escape, that there's some sort of red button that's like, "Okay, get me out of here. Everything will be okay," is sort of a mirage. In many cases, you can't, and particularly when we're talking about environmental toxins, as you point out in the book, thanks to plastics in the ocean, fish are detected ... well, something about 80-90% of all fish have plastics in them, and that's leading to effect all throughout the animal kingdom.

So I think you mentioned that dogs, their sperm counts have declined in and of themselves. So even though you're not hopefully serving the dog from the takeout container that was microwaved from the Chinese restaurant, they're still being affected as well. It's just ambient in the environment. But I want to pivot the conversation to the last component here, which is about all the different products and science and technologies that have come out in this industry, because I think 20 years ago you had a couple of different options for preventing pregnancy. You had a couple of tests, you had a couple of techniques in the office, so to speak, to evaluate sort of fertility health, but this has exploded in the last 20 years. You have a dozen plus period tracking apps. You have a dozen plus tests for both men and women around fertility and figuring out their health.

And then obviously as you get into pregnancy, there's just more and more options you can do. And then outside of this whole thing, you have egg freezing and all these other sections, and you have a whole nother chapter on this. So I'm curious because you're both an investor, you're in this, but you've also been a patient and someone who's used all these different, or at least some of these different techniques and tools. What's exciting and interesting and on the frontier here today? What needs to get more into the mainstream? What are people missing? Because in my view, there's sort of that William Gibson quote of, "The future's already here. It's just not equally distributed." And my view from fertility is we have a lot of things we're just not using that are on the shelf.

Leslie Schrock:
Yeah. I mean I'm very excited about companies Alife, for example, that is really applying the promise of AI and machine learning to IVF. There's so many ways that that process could be better. Right now it's changed some since its origins back in the late seventies when Louise Brown was born in the UK, the first IVF baby, but it hasn't changed enough. We're still kind of sending patients off with some shots and some basic timing and saying good luck. There are a lot of nuances to timing shots, all of the things related to that. So embryo selection is another one, but there's a lot we can learn from huge data sets. So I'm excited about what they're doing. I think also some of these treatments are overused. I talked about ICSI a little bit earlier. I think that for every technology that is developed, we need to really ask ourselves, is this making the world better for everyone if it is applied? Or is this just something that's going to give people the sense of control?

That's a common thing that doctors and patients will say when it comes to ICSI, as an example, is that, well, it may not increase the live birth rate, but it gives the perception of control. And the perception of control, when you're undergoing infertility treatments or even struggling with a fertility journey, is kind of everything, because you feel so helpless. You feel like you can't do anything about it. There's nothing you can do to make this better. And I think that that is why so much about the business could be better, because I think there's a lot that happens in a clinic that probably shouldn't because patients don't know and it's a cash pay business for the most part. Fertility benefits are great. They're not available to everybody. Insurance doesn't cover it. There are some states that have insurance mandates, but not everywhere.

But I think we have a long way to go on that side. I'm also ... Gameto, I'm very excited about the prospect of being able to age immature eggs outside of the body, which hopefully will not undergo all of those myotic errors during the maturation process if it's not susceptible to the issues in the human body. So that's a thing I get excited about. And then I think that we all need to just step back and think about whether or not we want to live in a world where we are so reliant on all of this, when there are so many things that you can do to try to put your best foot forward before you go to IVF. So no one should just jump into IVF unless you have a genetic condition that you're going to pass down or there's a well-established reason to do it. Most of the time there should be a more incremental approach. So I'm excited by some of the companies that are launching for ICI, that's intra cervical inseminations, basically the turkey baster method.

They are now their FDA cleared. Frida just came out with an at-home turkey baster method, which is really kind of phenomenal, because it actually has the same efficacy rate as IUI, which you would then go do in the doctor's office. IUI is over six times the cost, same effectiveness. So how do we ask ourselves, what can you do earlier? What can you do when you're first thinking about trying to conceive in terms of lifestyle improvements, in terms of really kind of taking a hard look at where you're at, assessing your medications, assessing what your exposures are, doing everything you can ahead of it. Because like I said, cannabis use, steroids, which men lie about in appointments, by the way, even when they're told that it has adverse effects on their sperm production. And then men's hair loss medication, all of these things that men just are never told. They don't come with reproductive health warnings. So what can we do before we ever have to rely on all of this technology to just improve our overall lifestyles?

Danny Crichton:
Well, I think one of the big things that comes out of that whole theme, and it really is sort of the spine of the book, if you will, from a thesis perspective, is this lack of information and the need to fill in gaps, which is 1985, you had Courtney Cox going on to an advertisement on television, and it was the first time the word period, at least in the context of women's health, was ever mentioned on American television, in the mid-eighties, which both makes sense ... it is also depressing, but also like, oh, I could see how that would happen in that period of time. And I just made a period joke right there. But I think the other side of this is as we get into a lot of the apps, period tracking, when you can talk about Alife with [inaudible 00:27:03], what we're seeing is we're actually collecting data from millions of people simultaneously, and that actually allows us to create best practices and actually disseminate the ways that these things work. So when you start talking about ICI versus I think it was IUI, -

Leslie Schrock:
Yeah.

Danny Crichton:
- you can start to do the comparative effectiveness research, whereas today. no one talks about it, no one's actually willing to tell their doctor what's happening. When everyone's sort of siloed we can't share what actually works. And that oftentimes means we lead to the technology first because that's America. We like to just start with our gadgets and gizmos as opposed to saying like, "Look, let's talk about it in a group. And because I've now learned that there are better ways to go about it, I feel better. I now know what the best strategies are. I can use the fertility window properly and if that doesn't work, these technologies are a great backup, but let's do the easy stuff upfront."

I want to finish with one final question though, which is you had a long journey, obviously, in fertility, in pregnancy. Obviously a lot of folks are suffering in the same way. That's why the book has been successful. That's why you've written two of them. How do you deal with the anxiety pieces to it? Because I think you've addressed a little bit of the sort of mental health component, both in terms of people's fears that they're infertile and they're not going to be able to have a pregnancy, as well as that sort of waiting period where you've copulated and now you're in this waiting zone, I think you call it the TTW -

Leslie Schrock:
The two week window.

Danny Crichton:
The two week window, TWW.

Leslie Schrock:
Two-week wait rather.

Danny Crichton:
Two week wait, the TWW, of sort of this what they now call a screening anxiety in medical terms. How do you deal with the mental health aspects of pregnancy on that side?

Leslie Schrock:
I think knowledge is a big part of it. Knowing that miscarriage has always been a part of pregnancy and that if it happens to you, you're in the company of many, I think makes it more normal. It makes it feel ... I mean it is truly a part of the process for so many people. It's been happening for a very long time, as long as humans have been here. So I think knowledge is such a big part of it, but I think the other thing that just has to change is just education. We just have to teach people how to take care of themselves. We have to teach them from a young age that periods are not shameful. Periods are not something that are gross. We have to teach boys, this is the period of time when you can get a girl pregnant. It's not during their period. I can't tell you.

And we have to teach girls how to track ovulation. And I think something that's very tangibly different in recent years is that conditions like PCOS can make ... cervical mucus monitoring, for example, which is you assess the viscosity of your cervical mucus, that doesn't work for people with PCOS because it changes the quality of your cervical mucus. So you have no clue based on that. Basal body temperature, you may or may not have any indication. Did you sleep well? Did you drink the night before? Did you get out of bed and then get back in bed? That all changes that temperature spike and your ability to interpret it. So I'm also kind of excited about some of the next gen fertility tracking devices that maybe you pee on a stick and it gives you a lot of information. The fact that they now contain progesterone test strips, which is the only way to tell if you actually did ovulate it. Most of the things you buy at the pharmacy currently just tell you about your LH surge, and that indicates you're about to ovulate. Progesterone is the only thing that tells you if you actually did. So I do think that there are other things that are really helping people at home tell whether or not they're on the right track.

Danny Crichton:
Well Leslie, thank you so much for joining us. Leslie Schrock, the author of Fertility Rules and Bumpin'. Second book, congratulations. Grab it at bookstores everywhere.

Leslie Schrock:
Thanks.

Danny Crichton:
Thank you, Leslie.

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