Fertility Isn’t Just Luck – How Hormones, Thyroid, and Lifestyle Shape Your Ability to Get Pregnant

Dr. Natalie Crawford, a reproductive endocrinologist, explains how thyroid function, gut health, insulin resistance, and stress shape fertility. Subclinical hypothyroidism raises miscarriage risk despite normal lab ranges. Strength training and a fiber-rich diet improve insulin sensitivity and egg quality more than most women realize.
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I'm so excited for today's episode because we are digging deep in fertility and we are talking with an absolute expert. Her name is Dr. Natalie Crawford. She's a board-certified physician in both obstetrics and gynecology and reproductive endocrinology, as well as infertility. She's the founder of Fora Fertility, a boutique fertility practice based in Austin, Texas, a digital health educator, and the podcast host of As a Woman: Fertility, Hormones, and Beyond with over 6 million downloads. Her debut book, The Fertility Formula, will be released very soon by Penguin Random House. So you might want to get on that preorder list. We are talking about root cause to infertility, how to pre-plan for fertility, what you can do in your life to maximize and optimize your own fertility journey. So I'm thrilled to share this episode with you. Let's dig in. Dr. Crawford, thank you so much for taking the time and educating and empowering our listeners today. I'm so incredibly excited to do a deep dive on fertility because as we were just chatting, this is a real issue in the population at large, but obviously in people that struggle with thyroid dysfunction as well.
Thank you so much for having me. Yes, it's incredible how— well, you know this— just women in general, how we don't learn about our bodies, we don't learn about our hormones. And it's really not until something is wrong that we kind of get on this path of exploration and education. And I find the two most common things that are going to happen first for a lot of people might be a hormonal imbalance like your thyroid, or realizing you have infertility.
Infertility.
And so this is really something that impacts so many people, and I'm so glad to sit down and talk to you about it today.
Yeah, you know, I was thinking, like, probably almost 15 years ago when I was practicing medicine, someone came in with a hormone issue, and I'm like, you know what, I don't know if I was ever even properly taught about the hormone cycles and what normal looks like. So let's kind of open with that. Tell us what is happening in our body, in a woman who still cycles, who still has a period, for the duration of the month, like the first part, the last part, what does that even look like and how should we know if it is quote normal?
Perfect. Menstrual cycle 101, which is really one of the best ways to understand your reproductive hormones. So we always talk about, oh, you'll hear people say, are your hormones balanced? Are they not? And I wanna start this by saying it's very difficult to draw blood and look at the reference ranges and know, is this really normal or not? You have to learn how to listen to your body, know what's normal for you. And one of those really big red flag warning signs is a change from normal. But that begs the question, what should be happening and what is normal? So to sum up that menstrual cycle and thinking about how the hormones play together, let's imagine that inside the ovary is a vault where all your eggs are kept. So when you're born, I like to think about that vault being very full. Throughout your life, eggs are coming out of the vault, and eventually that vault will be empty and you'll be in ovarian failure or menopause. But what's happening on a month-to-month basis during those years is that a group of eggs is all being sent out of the vault at one time. Each egg is really microscopic, and it grows inside a fluid-filled structure called a follicle. So I can do an ultrasound and look at somebody's ovaries, and I can see the follicles. I can't see the eggs, but there's one egg inside each follicle. The terminology is important because this is one of the really few places in medicine where things are actually named over what happens to a woman, because the brain sends out FSH, or follicle stimulating hormone, and FSH stimulates a follicle to grow. So this is the signal to get that follicle to grow, to get the egg to mature, and to get estrogen really making? The ovaries love to make hormones. Estrogen is only made in high doses as the egg is maturing. So this is that first part of the cycle. We consider day number 1 to be the start of what's known as the follicular phase, the phase of growing a follicle. Day number 1 is that first day of full flow when you're actually bleeding from your period. And it's that rise in estrogen coming from that follicle that actually stops you from bleeding because estrogen allows the lining of the uterus to really grow and develop in preparation for potential pregnancy. But it's also what starts to give you increased energy, concentration, makes your skin better, your hair better, your libido higher. As your estrogen rises, you start to feel— we'll always say like your kind of peak self. For most people, the follicular phase is going to be in different lengths for different people. A lot of times people think that this should be set at 2 weeks because we use a traditional like 28-day cycle for the example purposes. But some women have very normal cycles and it's longer. Or normal cycles, and it's shorter. And we're gonna come back to why that's important. But let's just say first half of the cycle is a naturally estrogen dominant phase, meaning estrogen is made, no progesterone. When estrogen gets to a high enough level for long enough, so when it's at 200 picograms for 50 hours, the brain is actually that sensitive. It is waiting to see that estrogen signal come back to tell it that there is a mature egg and that it's time to ovulate. And so the brain and really all of our other organs, so whether it's the thyroid, the adrenal glands, your ovaries, the brain can't see what's actually happening in these different organs. It is relying on the messenger coming back, and your brain has to be able to actively interpret that appropriately and send out the right signal. So you can kind of hear so many different players involved. It's a beautiful system when it works perfect, but there's so much opportunity for things to go wrong. But when the brain sees that 200 picograms for 50 hours, it says, oh, this must be due to a mature egg. This egg is now ready to ovulate, sends out a surge of a hormone called LH, luteinizing hormone. And what LH does is it allows the follicle to actually rupture. So the follicle's a cyst, so it bursts, the egg is released from it, and ovulation occurs. That egg must be fertilized within 24 hours or it's overmature. So it's a very actually short window to get pregnant. But then the follicle is going to reform, and it becomes known as a cyst called the corpus luteum. And this corpus luteum is now going to make many hormones, but notably progesterone. And what's important is that it's going to make progesterone impulses from the brain because the brain is sending out LH impulses. Unlike the length of time from the follicular phase, which can vary woman to woman, the luteal phase is typically much more set when everything is working normally. So let's say that a corpus luteum should be able to live for about 2 weeks. If you get pregnant, then it is stimulated to live longer. But if you don't get pregnant, the corpus luteum will die, progesterone will drop, and then you will get a period and the cycle will start back over. And that second half of the cycle, which is based on when you have the corpus luteum, is called the luteal phase. And this is known as a time where you have both estrogen and progesterone. And progesterone, that's a fascinating hormone because it's progestational, right? It's trying to get you pregnant and it completely changes how you feel. But I think one thing that I always say is we say, well, what is normal? Normal should be a very regular, predictable cycle, meaning for you, you should know, okay, if I gave you a calendar, McCall McPherson McCall, you should be able to look at it and put your finger on when your next period is going to come and be only 1 or 2 days off. It should not be like sometime this week, I don't know. And a lot of people live in irregularly regular, what I call it, meaning their period's not going to skip a full month, but they can't really pinpoint when it's coming. And those are people who probably have subtle ovulatory issues. Another really common one, because the brain again is interpreting and sending out, is the first sign of ovulation issues is actually a shortening of the luteal phase. And so if you are just marking your day number 1 on your app, you may not know that that's happening because you might say, hey, it's coming at a regular interval. But when we get into the nitty-gritty and say, when are we actually ovulating? Oh, how long is each phase? That is when a woman can really leverage their menstrual cycle to be a vital sign for your full hormonal health, at least when it comes to your reproductive hormones.
Interesting. And when you're trying to put those pieces together, like when you're trying to detective work this system and see what point there might be failure. How are you looking for that? Are you doing like weekly lab draws of hormones? Obviously, you take into account the cycle duration and that sort of thing, but tell me what that looks like from a fertility detective standpoint.
Let's say that you, you think your cycles are regular. You're just trying to detect maybe when ovulation occurs, trying to know, are they normal? Right. Because regular is an important piece of normal, but doesn't mean that they are exactly normal. There's more to the puzzle.
It's actually—
lab work is not that wonderful. For this because your progesterone level is going to fluctuate up and down. You know, it's a very responsive system. So one of the best things to do is to learn to track your cycle and with what we call fertility awareness methods. And these are physical clues and symptoms that your body's giving you from these hormonal changes. So for example, when your body has peak estrogen level, we said has to be high and long. One thing that that high estrogen does is it changes the cervical mucus. So the cervical mucus protects the uterus. The cervix is the entry point to the uterus. So that nothing can get in and cause an infection, except it wants to allow sperm in. So it changes to be sticky, stretchy, and egg white when it sees that really peak estrogen level, and that's called type 4 cervical mucus. So I always recommend cervical mucus monitoring, which is free, easy, and cheap. Essentially, you're going to just wipe before you go to the restroom, look at the toilet paper, see if you have any mucus there. It looks like an egg white. When you see it, you know it's there. That is considered the day of ovulation. So one easy way to start tracking is look within your cycle pick out that cervical mucus day and say, okay, this is the day. And a couple other ways. One is urinary hormone measurements to detect the LH surge, understanding that LH will go up and down the whole luteal phase, but it's not going to be present in that follicular phase in very high levels. So if you can detect the first moment you see it, you know, oh, that's my brain sending out that surge to get me to ovulate. And there's many different fancy expensive hormone trackers now, which some people love data and those are fine and they're accurate, but there's very inexpensive urinary LH tests too that work just as great. And one of the keys here where I think some people mess up is that LH is actually released from the brain in the early morning hours. So if you get up, you work a job like you and I do, you urinate really early, you may get a negative test and it may be out of your system by the next day and you may never catch your positive. So I say if we're really going to do urinary-based hormone measurement, much better to work between 10 AM and 2 PM, because by that point, it's going to be— the hormone will be released from the brain, go through your bloodstream, filter through your kidneys, and be in your urine in a high enough level to detect it. So I say one time a day, 10 AM to 2 PM. You want to start testing well before you think you're going to ovulate so you can catch that first positive. And once you get that positive, ovulation's the next day, and you don't need to spend money using them because they're going to be on and off positive because of those LH pulses. And then the third option that I used to never recommend, because even back when I was trying to get pregnant, I tried to do this and it was so tedious, was basal body temperature tracking. However, this is something that the tech has actually made life a lot easier now because now tech has so many wearable options to track your temperature that makes it a lot less sensitive to some of the other changes that just you know, if you were trying to get the 1/10 of a degree thermometer and measure it every morning and graph it yourself on graph paper. The idea here is that when your body makes progesterone, it actually completely changes the entire metabolic parameters for your body. Your resting heart rate raises, the variability decreases. But one thing that happens is your core body temperature increases. So if you see an increase in your body temperature of 0.4°F, then you know, okay, I am now making progesterone. This algorithm used to be something we said, okay, let's just use this to confirm ovulation did in fact occur. But if you're really tracking your temp through your whole cycles, it actually drops because of the follicle rupturing right before it starts to raise, and you can detect that in specific algorithms. So I think that the— all of these are great options. You don't have to use all of them. You can use just one. One of the important things though is that they're all testing different things, and you've got to learn what's normal for you. And so pick what's going to feel better. If you're trying to get pregnant, I will say studies have shown that any method of fertility awareness, so any of the 3, is better than none, will help you get pregnant faster. And using 2 methods, dealer's choice on which 2, help you even more. And that makes sense because now we're using a couple different endpoints to really pin down when did I ovulate.
If you—
if your cycles are not normal and you know it, if your luteal phase appears short, or you have spotting in your luteal phase, or you can't put your finger on a calendar That is not a DIY at home, let's try to figure out what's going on, because there can be something wrong that we need to know about. And that's when I always recommend blood testing. So it's not that lab testing is really super helpful just in the context of, you know, when did I ovulate every single month, but in saying, could there be something more going on? We always want to look at your thyroid, we want to look at your prolactin, and we want to look at an AMH or an egg count, because we know at highs and lows of your egg count, the brain and ovary communication gets a little muddied. I like to say the ovary gets a little more stubborn. If the thyroid or your prolactin is high, which is a pituitary hormone that interferes with brain's interpretation and ability to send out hormones. And so those are some of the common things that we really want to rule out if you know you're having some period abnormalities before we just say let's detect ovulation and see. You might need, you know, medical option to normalize your cycle first.
I love it. Okay, talk to me too. So it seems like like even over the last 5 to 10 years, and maybe my data set is skewed because I serve thyroid people, right, but I feel like infertility is becoming a real issue. Like, people, it seems, are struggling more to get pregnant now than they were 30 years ago. Do you feel like that's accurate? And if so, also you can tell me that my data is skewed and McCall, it's not accurate at all, because I'm sure you know that's why I'm asking. And also, like, what could be contributing to this? Like, what's going on where is becoming more of an issue.
You're spot on, and data supports how accurate you are. You know, when I entered the field almost 15 years ago, we used to say 1 out of every 8 couples would have infertility. Now worldwide, that number is 1 out of 6. And if we look in the U.S., for couples trying to get pregnant for the first time, it's 1 out of 5. So we are seeing a definite increase in the incidence of infertility. We are also seeing an increase in a lot of things you know, other markers. So higher rate of miscarriage, higher rate of women having a low ovarian reserve or low egg count, huge drop in sperm counts over 40 years. So we're seeing multiple fertility markers besides just can you get pregnant showing this temporal change over these decades. And it's not a coincidence that these things are changing in the same time where we have a more inflammatory world, more, you know, insulin resistance and diabetes and autoimmune disease. The truth is that we have normalized as a society a really unhealthy way of living. That's not self-blame, but that's just the world around us, whether it's the toxins that we're exposed to, what's in our air, what's in our water, the foods that we eat, how they are processed, and the hustle culture of I'm not going to sleep, I'm just going to go, go, go. And all of these little things, they actually add up. And when your body is constantly under this stress, under this inflammation, it wants to protect you first and foremost. And your brain, I always say that inflammation, it's interference coming back to the brain. So if we think of Brit, the brain being central command, it's like air traffic control, and it's trying to send out signals to different planes and hear back from the pilots. Well, if there's static on the radio, it is going to interfere with these things. So it's going to put us into a position where suddenly the brain maybe hears a wrong signal or doesn't send out a strong enough signal. And that is really one of the things that we're starting to see as far as hormonal— we'll say balance hormonal balance, which I always say balanced hormones are your brain being able to properly interpret and send out and end organs responding. It's not a set of lab values that's perfect. It's how your body actually acts and how it responds. But then also inflammation is really toxic to our eggs and our sperm. So both females and men, when we think about what an egg and a sperm is, and it's so incredible, it's a single cell. That is mostly filled with water that holds the DNA, and it holds it in perfect position, you know, the vast majority of time. And your egg is even more important because it holds the mitochondria that go on that fuels all of embryo development, which is cell division and organ formation. And when we have inflammation in our life and insulin resistance in our life, it causes stress within the egg. It causes the mitochondria to be damaged, to not function correctly. It can interfere with how the chromosomes are held in line. And so we see a change in egg quality and sperm quality that is contributing all further to some of this increase in infertility. And this, this data is really scary. And of course, we're not sitting here trying to scare people, but to make people aware, because if the unknown is the scariest, and when I hear this and people say, oh my gosh, that's overwhelming, I say, well, you know, we know one variable of your fertility we cannot change is your age, right? Your eggs have been inside your body your whole life. There is some age-related accumulation of wear and tear that will always happen, even if you're living perfectly. But you control a lot of decisions that can make that better or make that worse. And that, to me, is really empowering because we're switching the message instead of being, oh, fertility is just good luck or bad luck, and we're so sorry you fell in the bad luck category, to saying, hey, we acknowledge we live in a society, in a world that is really pro-inflammatory, and I'm going to start to craft a life that may I know how my body works and what it's supposed to do. I know how to advocate for myself, and I know when things are wrong so I can get help. But also, I know how all these lifestyle choices that I'm making are actually playing a role in my body, and I'm trying to minimize that risk earlier on so that I can have a longer health span, but also a higher chance getting pregnant if that's what somebody is looking for.
I love that. That's so empowering and just allows people to control aspects of this process that that can inevitably influence their ability to get pregnant. You know, I know we were chatting about this before we, we got online, but I know thyroid is directly related to infertility too. I've been really digging into data on subclinical hypothyroidism.
Yes.
And, you know, the hypothyroidism that no one wants to treat, but it has incredibly damaging long-term health impacts. And one of those is fertility. I'd love for you to just add in add some color to anything that you've kind of dug into in your book writing process and in your career about thyroid and infertility as well?
Oh my gosh, I could— I have a whole soapbox on this one, so I'll just give you a little bit of sister, a little bit of background. You know, when I was in training, you know, I had, I had many miscarriages myself, and I was told what many patients are— it's bad luck, there's nothing you can do, just carry on. You know, a decade later, I got diagnosed with celiac disease, so there actually was things I could have done differently. But during this time when I kept hearing this and I kept seeing patients and I was a fellow, I was in fellowship. In infertility fellowship, it's 3 years long after OB-GYN training. And in fellowship, you have to do a year and a half of research, and most fellows do IVF projects. And I mean, that makes sense. That's what a lot of fertility doctors do. And I remember marching into my fellowship program director and saying, I'm going to study natural fertility. There are questions that I have that I don't have the answers on. I want to know what causes luteal phase issues and what about the thyroid and what about environmental toxins. And I used to give grand rounds on thyroid and fertility and thyroid and pregnancy, and I even wrote a chapter in a book. So we are so aligned. And the general theme that I really found during that time saying, I want answers to the questions that I have and that my patients have. And I remember they said, oh, you'll have to get a master's in clinical research because clinical research is so hard to understand. And I said, great, sign me up, I'm there. Was that there was so much talk about inflammation in the literature, yet so little talk about inflammation in clinical practice. In clinical practice, we only talked about it in disease state. Oh, you've got some inflammation now that once you've developed this disease. But when you start digging into the plethora of research that starts to exist on different hormonal conditions, you start seeing that associated with inflammation markers and people who are in this quartile of that were more likely to have this other cascade of events. And the one thing that struck me about this, and this was a decade ago, was subclinical hypothyroidism, which your audience should know this, but we'll kind of level the playing field. This is when, based on your blood markers, anybody would look at you and say you're totally fine, everything's normal, don't worry about it. We talk about lab markers. We have to understand that most labs, first of all, normalize them to population norms. So they're going to say in this group of people, what are average levels? And then they're going to set those those as their ranges. So they're really not very good when a population is also getting sicker at catching what is optimal. So just because something might flag normal doesn't mean it's optimal. When it comes to subclinical hypothyroidism, this means your brain is essentially seeing that whatever your thyroid hormone in your blood is that's coming and talking back to your brain isn't, isn't sufficient for the brain to feel satisfied because it is sending out signs to try to get the thyroid to work harder. And so when have this imbalance, meaning the blood level might look okay, but in reality the brain is not happy and it is saying, please thyroid, make more hormone. That is your body being under stress and a sign that your body is going to have increased inflammation and a sign of other issues down the road. Meaning women who have subclinical hypothyroidism may have a higher risk of infertility, a higher risk of miscarriage. And often there's a lot of debate on this in the literature, and it's important to— I don't say literature, in professional societies. And what we Endocrine Society and ACOG, they're not always in agreement because you'll hear people say we shouldn't screen the general population for this. And you'll hear Endocrine Society say, well, anybody with a risk factor, being over 35 or being fatigued or a first-degree family member or having infertility or having irregular cycles or having a miscarriage. And that's my whole population. But when you go and you look at these women and you say, hey, this isn't perfect, and you draw thyroid antibodies, you're gonna find a lot of them actually have some positive antibodies. And this is that red flag that, hey, we're not really functioning normally. And so why do we have to wait till you get so super sick and before we're going to treat you, especially when we know thyroid interferes with how your brain's gonna function when it's a sign of your overall body's health not being ideal. And to double down, the moment you get pregnant, you need 30% more thyroid hormone, right? That baby cannot make thyroid hormone, for the first 11 weeks, it is completely dependent on your thyroid hormone. And so we're saying, Natalie, right now, your brain already thinks you don't have enough, but we're not going to treat it knowing that if you get pregnant tomorrow, you suddenly are going to need 30% more. Your thyroid gland is not going to be able to do that. Okay, so I did go on my soapbox, but what you can see here is that one thing that I think is really important, I know you do too, is saying we have to understand when lab testing is powerful and its limitations, that your clinical signs and symptoms are really important as well. But also thinking about our body, especially as women, turning the narrative instead of you have to be so sick that it's going to take you a decade to get to this diagnosis, to saying, if your body is giving me a red flag, I need to stop and listen. Why don't we try to intervene and get you healthier, but also to feel better.
Right.
These women are so gaslit into saying my fatigue is normal, I'm gaining weight, I'm losing my— but it's normal because my T4 is fine. And so they kind of get into this place where they're kind of gaslit. And then in early pregnancy, their thyroid can't keep up, and then they're trying to add a new medicine on. And to me, that is just highlighting the reactive nature of modern medicine that we live in right now, especially when it comes to fertility.
Right?
Because when it comes to your fertility, if you're trying to get pregnant, this field exists as a reaction to a problem. People who didn't get pregnant for 12 months of trying, then they qualify for an evaluation and kind of get to come into the office. We get to figure it out. And I think if we can acknowledge infertility is rising, we can also say maybe this doesn't make sense to be so reactive anymore, and we need to start working backwards and being proactive, which is learning about your body, listening to red flags, testing for things earlier, and having a lower threshold to say, I'm going to intervene so that you can feel better and try to prevent a problem before it gets really bad.
Can I tell you how much I love you right now? Like, oh my goodness, preach, sister. Absolutely. Especially, I think it's uniquely important for fertility because these women are on a time frame. Like, we don't have all the time in the world. And if we're just waiting years to see what's happening without looking deeper, without looking for answers, we are so reactive. And at times, I'm sure, too late, which is devastating for the future that these women envisioned their entire lives, right?
You're so right, because because so few things in our life make you reevaluate your entire sense of self, and infertility is one of them. If you envisioned being a mother and suddenly this may not be what your future holds, it is challenging the core identity for so many people. But your fertility is finite. As we talked about age and accumulated damage, many women think one day I'll run out of eggs and then I won't be able to have kids anymore. But the reality is one day your eggs will become so damaged they won't function normally anymore, and that's what will halt your fertility much before you'll actively run out of eggs. But because so many of these different factors are important in your journey to conceive, it's really important to start paying attention to them, you know, as soon as you can. I mean, if you're trying now, we'll start paying attention now. But in the perfect world, if we could empower a younger generation of women to learn about this, to learn about their hormones, to really think about about their lifestyle and thinking about their fertility at an earlier time. McCall, I've seen so many patients who will come see me after a year of trying, and then when I talk to them, they've had 3 periods, or they have this raging— their thyroid is way out of whack and things have just— you can watch it over years just getting worse, but nobody's intervening yet. And I know you have these stories too, and it's really hard to see It's not any patient's fault. It is the current state of medicine. And what I say is that you, as a woman, especially as a woman who wants to get pregnant, this is your journey and nobody else's. And you've got to feel comfortable advocating for yourself. The squeaky wheel gets the oil. And if your doctor is gaslighting you, not listening, go find a new one.
Amen. Don't try and change your doctor's practice of medicine. And you should never have to convince someone to believe you. I always say, like, look, women have so much to do in a day. We, we are overwhelmed, we are overloaded. The last thing we want to do is take time out of our day to go sit at a doctor's office or a clinician's office and, and convince them that we have a problem that's real. Like, we don't want to spend our time doing that. So if we're there, it's probably a real problem. Like, they can believe us. It should be that simple. But sadly, in, in so many cases, it's not. Um, but thank you for your work in that. At Modern Thyroid Clinic, we talk so much, and I know that you do too, about the concept of pre-pregnancy planning. Like, let's start working on this now if you want to get pregnant in 2 years, in a year, etc. And that's so valuable. And it sounds exactly on par with what you believe in. So thank you for that. You know, switching gears just a little bit, I'd love for you to talk to me a little bit about gut health. This is not something that people talk about in the realm of fertility. So let us hear it.
Okay. So if we, if we think about this idea that your hormones are a delicate system and that inflammation is one factor which can really throw things, we'll say, off balance, right? It's gonna interfere on many different levels when it comes to both quality and functionality. Well, one of the biggest barriers of your body, your protective systems against inflammation is actually in your gut. So we just think about our gut. We think about the fact that you've got a gut lining that are cells that are one cell layer thick. And this is called your intestinal permeability, meaning there's these little gaps between these cells as your gut gets less healthy or gets more sick that can allow toxins, inflammatory particles directly through your gut into your bloodstream. So you can have a direct reaction through this leaky gut, which is what that's loosely called in popular culture. But also an important aspect here is that your gut has a microbiome. And I know people think about their microbiome, or they may have heard of it, but we haven't really connected the dots well in the general public for how that relates to hormonal health and your fertility. So your gut microbiome has a variety of different functions. Let's just say it is one of the top sources for fighting inflammation you have, but also for hormone metabolism. So your gut microbiome is actually super important in metabolizing hormones. Which is important for your brain to know actively how much hormone is in your system. Well, when your gut microbiome is off, this is called gut dysbiosis. So essentially you have an abnormal microbiome. You're suddenly now going to have increased inflammation. And some of the things that cause this leaky gut, gut dysbiosis, these are things that when you have a very low fiber diet— so fiber is the fuel, the food of the gut microbiome. That's your fruits, your vegetables, you know, some of your grains, these things that have really great fiber sources. Animal protein does not have fiber. So if you're on a carnivore-only diet, you may not be getting— you're not getting enough fiber. And people don't really— they just kind of poo-poo that. I always say protein is everybody's favorite right now, and it's very important, but fiber is more— like, I wish we talked about fiber more. But also, you know, when you, when you pull in toxic foods— so there's foods that can help your gut, and that's going to be your fiber-rich foods, and there's foods that can hurt it, and that's going to be your ultra-processed foods, your added and artificial sugars, and, you know, things that have high levels of toxins as well. These things all cause increased inflammation, but they double hit because they also cause an increase in insulin resistance. And, you know, your audience loves hormones. So most of my patients, when I talk about insulin resistance, they'll say, well, I don't have diabetes, or I don't have diabetes in my family, so this one's not important for me. And this is actually, I think, one of the biggest areas that we're not talking about enough. So insulin's a hormone just like all our other hormones. But insulin's job, I always say, is to open the door and allow glucose, which is what your food gets broken down into, to go into the cell. And glucose is the food of the cell. So insulin has a really important job. And when things are functioning perfectly, you eat food, insulin raises, glucose goes in, then glucose and insulin go back down. But I liken it to imagining there is a salesman coming to your door and knocking at your door all the The more frequently you see that salesman, you hear your knock on your door, you're going to stop answering. And this is what insulin resistance is. When you're eating more, you're eating these high sugar foods, you're getting high— it's called high glycemic load— you have more insulin released and your cells essentially get sick of seeing the salesman at the door and they stop answering. And it takes even a higher level of insulin to get the door to open, meaning now the salesman's like banging at the door so you finally go pay attention. And this idea year is actually one of the most problematic things because high insulin then is going to have your body store visceral fat. It itself is inflammatory and it's worsening the entire system. So if we think about inflammation and insulin resistance being on this never-ending chain, the other things that really play into gut health that aren't talked about enough, or ways to combat it, is going to be obviously the dietary health is, is really has to change first because you You know, outwork, can't de-stress a bad diet. If you're putting things into your body that are inflammatory or, you know, they cause high levels of insulin to be released, you're not going to be able to break out of the cycle. You know, insulin resistance can happen, you know, even directly at the ovary, can cause high androgen level production. And we talk about this or think about this a lot in PCOS or polycystic ovarian syndrome. Syndrome, because it's one of the metabolic changes we see there. But even in women who do not have PCOS, insulin resistance can cause worsening of IVF outcomes, lower pregnancy rates, higher miscarriage rates. So it is not a disease state that we should just bundle with diabetes or PCOS and ignore otherwise. We actually, again, we live in such a pro-inflammatory world. We live with a diet that causes people to become insulin resistant, that we've got to start changing our habits both in what we eat but also how we actively manage this process as well. And so a couple of things I want to mention in my rambling is going to be— one is going to be muscle health because there's a lot of chatter about exercise. And I know you talk about exercise a lot when it comes to thyroid, and especially our patients get really overwhelmed by all the different recommendations that are out there.
There.
But the simplest one to say is that building and using skeletal muscle is one of the best things you can do for your hormonal health. And there's a variety of different ways that you can do that. But essentially, when you use your skeletal muscle, there's a transporter called GLUT4. But what it does is it allows your glucose to enter into the cell and doesn't need insulin. So we can, you know, it's like a key to the door. Nobody needs the salesman anymore. So suddenly now we can get glucose levels lower, we can get insulin levels lower, and we can start to break the chain. And so that really is not how you and I were trained nor raised, right? It was all about minutes of activity. It was all about aerobic exercise. And so this is building and using— this is strength and resistance training as the core of what you choose to do when we're focusing on proper hormonal health and fighting against insulin insulin resistance and inflammation. And the other thing to acknowledge is that chronic stress isn't just this thing to wash off like so many of our colleagues kind of do. And I understand it. It's because a perceived thought that a patient won't receive the information well. But when we are so stressed, your body actually changes on a cellular level. And so if we think Now, the olden days, right? When would you get stressed? You would get stressed if there was a bear. So you're like, oh my gosh, we've got to run from a bear. And when the stress hormone, which is called cortisol, is released, you'll hear people say, well, cortisol is inflammatory. And that's true. That's true. It is. And the reason that it is, is cortisol wants you to be able to properly run away from the bear. So it is going to suddenly— you're going to have more glucose, more insulin. It's going to free up glucose. Glucose so that you can run from the bear. And back in the olden days, we would run from the bear. So you would go run and that glucose would use your skeletal muscle, it would get used up, and your insulin would go down, and you would return to homeostasis or that state of balance. So you'd see a stressful situation, you'd go use up the glucose that was released and get back to normal life. Well, now what happens is that we encounter stress so commonly and so self-imposed, but so much of it is also from our interactions during the day and at a desk. So you get a stressful email, you're in a bad meeting, you get bad news at the doctor's appointment, and you don't go get up and take a walk or go do anything to use this glucose, which has just been freed. And what that's going to do then is promote even more insulin resistance. And that's why chronic stress is associated with insulin resistance and worsening all of this idea. And the thing about stress is that there's no one magic pill, there's no one magic answer. I tell my patients, hey, the world is stressful. Let's just acknowledge, right? The idea that we're going to go set boundaries and cut out all of our stress is really unrealistic. There's things that we do though that make it worse, right? When we don't sleep enough, we make it worse. And, you know, when, when we eat really crappy food, we stress eat, we make it worse. And we drink alcohol and we make it worse. So we can take this, this level of stress and we can double down. But we could also say, okay, I know the world is stressful, so how do I carve out 20 to kind of get my cortisol to lower every day? Because every day will be stressful, right? How do I fight that more proactively? And there's no one right way. And you and I would probably choose different things because we're different people. So maybe it's meditation, mindfulness, acupuncture, walking, journaling, talk with a therapist, talk with a friend, feet in the grass, seeing the sunshine, walk with the bird. They're all good, right? And saying, what's going to work for me? What gives me that feeling? And I would say it can't involve a phone, right? It needs to be just like you without the phone. And then also to say the knowledge that when you do encounter that stressful event, like, get up and go do something about it. Like, if you can, you get the bad news. We all know that feeling when something stresses you out and you get that tight feeling and your heart rate increases. And you're not going to be good at functioning. So if you can, try to say, "All right, hey, I need to step out for a few minutes," and try to go for a small little walk or do some squats at your desk. If you can't do that, do something to say, "Glucose is now in my blood. Can I use it?" And really try to fight against what is trying to happen to my body because my body is not meant to live in the modern world. So we've got to adjust the choices that we're making in order to fight what is naturally happening.
I love that so much. And what I appreciate about your approach in this conversation is so much of it is allowing people to make decisions with the information that you provide to improve not only their fertility, but their, their health outcomes, their lifespan, their healthspan, everything. So that's so powerful, because I think for so long, medicine kind of did disempower people, you know, it was well, the clinician, the doctor, they know everything, and I just have to receive it and then do whatever they say. You— this is so much more. It allows women to be in, in control of their health. And so, you know, to summarize, help me with any ones that I miss, but obviously we want to be empowered to know what's happening in our body with our hormones on a monthly basis and using those skills that you taught us. And I know so much of this and much, much more is in your book coming out, The Fertility Formula, which we'll talk about in a moment. Tracking your cycles, making sure your thyroid is in order, reducing inflammation, improving gut health, building muscle mass, right? Which is so cool to tie that in with fertility as well. And reducing stress. Anything that I missed in those that we covered today?
I usually say sleep, right? So sleep, which I kind of— we kind of tied it with reducing stress, but I would say that's the number one thing you should do, the very beginning of this, because it really doesn't take money, it doesn't take a huge behavior change, change. Start by sleeping at least 7 to 9 hours a night. Your body's like a toddler, so if we can stick to your circadian rhythm— it likes to know, I'm gonna get this rest time so I can go and heal and fight inflammation and lower my cortisol. It wants to have that moment to do that. So the, the more you can stick to a regular sleep pattern and give your body the rest, the better that it will be.
I love it. So I have one more question. Before we ask that, I want you to tell us a little bit about the Fertility Formula your book, where people can find it. Tell us everything.
Thank you. Yes. So The Fertility Formula exists because I'm sick of sitting across from women and everybody's saying, I wish I'd had this information sooner. So it really is going through this idea that women deserve this knowledge and that they're smart enough to understand their body if you teach it to them. And if you tell somebody why their body's working this way, that is the number one thing that will actually help them drive change. So if you understand what is happening, then you're motivated motivated to say, why am I doing this? And one thing that's really overwhelming is that having infertility actually puts you at higher risk for a lot of other health diseases later on. So it puts you for metabolic syndrome, heart attack, stroke, cancer, earlier death. And I had infertility, so that data sounds really scary. But to repackage it is that your fertility is a health marker. For many young women, it's one of the first medical problems you will have. It is again that huge red flag that more is happening in your body at a cellular level. And it's your turn to take that information and change the trajectory of your health so that you can not only get pregnant easier, but live longer and healthier. So it works through, you know, hormones, ovarian reserve, egg quality, tracking your cycle, when you want to get pregnant, infertility. I would say that's the first half of the book. But the second half is tying it all into inflammation, these lifestyle choices, talking about studies and giving women the science so they can understand how am I going to actually start to make these changes and what decisions are right for me. And it's not an all or nothing, right? Like, every little decision you make adds up. It's the sum of your choices. Choosing to treat your body kindly, you can then handle the bumps that are going to come down the road later. So I'm thrilled that The Fertility Formula is finally going to be in the hands of everybody. And if anybody wants to buy You can buy it anywhere books are sold, but they can also learn more on my website at nataliecrawfordmd.com/book.
I love it. Thank you. I will be sharing that with my patients. Absolutely. Because this is a topic that's so mysterious and sort of behind the curtain. So I love that you're pulling that back for people and giving them direct information, the resources, the studies, and that the applicable nature of what they can do. One last final question for you. If you you could leave our listeners with one thing, one message, one tidbit about their fertility, what would it be?
You have more power than anybody tells you that you do, and that you deserve to understand how your body works, but you also deserve to control so much more of this journey. Don't just be a passive player when it comes to your health or your fertility. Feel empowered to take charge, both of owning and knowing what's supposed to happen, but also that you're making the right decisions for you and you're making them out of— with data and not out of fear.
So many parallels between fertility and thyroid and women on their journeys. Thank you so much for advocating for us, for women struggling with this. It is an incredibly difficult journey. So thank you for all the work that you've poured into supporting us, and I'm so excited to share your message.
Thank you so much for having me. I feel like we could talk all day.
We absolutely could.
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