Everything You Need to Know About Thyroid and Fertility with Dr. Christine Maren
Dr. Aimee: Fertility and thyroid is something that so many of my patients ask me about, so it is so great that I finally have an expert on my show.
Dr. Christine Maren: I am so happy to be here. It’s one of my favorite things to talk about.
Dr. Aimee: I would love to hear more. Why is it one of your favorite things to talk about?
Dr. Christine Maren: Thyroid is near and dear to my heart. I’m a thyroid patient myself. So is my sister, and my other sister, and my mom, and my mother-in-law and so many other women I know… and aside from my family, just so many of my patients.
I see people change their lives and change their family’s lives when they get their thyroid treatment. It is a big deal in terms of quality of life, really. And, as you know, fertility and pregnancy outcomes.
Dr. Aimee: So, you have a very personal story related to it, but tell us more about why you also went into medicine and chose your specialty.
Dr. Christine Maren: That’s a blast from the past. Actually, I was a finance major. Little known fact about me. I graduated from the University of Colorado at Boulder Leeds School of Business. During that time, I studied abroad in Mexico and I also did an honors program called Presidents Leadership Class. Both of those things just really instilled in me a sense of service, and as cliché as it sounds, I really wanted to help people.
My goal was to find a profession where I was really helping people. I remember sitting in finance class and my friend sat down next to me, and at that time he opened the newspaper and he was reviewing the stock market, and I was thinking to myself “I could care less about that.” I was a group fitness instructor and was reading about health and fitness and nutrition, and I was really into that.
So I made a big change after my time abroad, and started my pre med studies. I started taking organic chemistry and I loved it (most people dread that class and I really loved it!). I found that I was really into the sciences.
After I finished my undergraduate degree, I went on to osteopathic medical school. I was really in this very holistic mindset, just part of my upbringing, and part of my environment. I went to undergrad in Boulder and was surrounded by acupuncture and Reiki and holistic modalities. I also had hormonal struggles myself when I was in college, and the thing that helped me was acupuncture, so I already gravitated to a more holistic path.
Dr. Aimee: Where do you practice?
Dr. Christine Maren: I am licensed in Colorado, Michigan, and Texas, so I have a virtual practice in all of those states. Long story, but I went to med school in Chicago, met my husband who was a military doctor, and we traveled around because of that. He was honorably discharged and we’re now settled in Colorado, so I’m back home and close to family.
Dr. Aimee: You shared a little bit about having a personal connection to the thyroid. Do you also have a personal connection to fertility, that you’d be willing share?
Dr. Christine Maren: I do. Much of my story really started with pregnancy struggles. In residency, I had my first daughter. My husband and I actually got pregnant pretty easily, but I had some unexpected complications. I had gestational diabetes, and zero traditional risk factors. I really dove head first into nutrition at that point. I checked my blood sugar four times a day because I was really determined to avoid medications. I wanted to have a healthy pregnancy and I wanted to find some answers about what was going on.
Fast forward several years, my husband had deployed and when he came home, we were on a timeline to have our second baby. It took us about four months to get pregnant and then I had a miscarriage. My intuition told me there was something wrong with me, because meanwhile I’d been dealing with new digestive issues, skin rashes and just felt off. And then it happened again.
At that point I was like, “All right. I need to figure out what is wrong. Something’s going on with my body.” And indeed it was. That was my deep dive into functional medicine and the time when my professional and personal lives collided. I saw a fertility doctor who was wonderful, but ultimately my diagnosis was unexplained, and I felt like, “Well, there’s got to be an explanation somewhere.” And that’s when I became a functional medicine patient.
Eventually we had our second child, thanks to thyroid medication and progesterone. I got my health back after that, and I was feeling really good… and then I got a surprise: baby number three. She’s wonderful and I love her to death.
I tell my patients, “When you get your health back, often your fertility comes back too.” Obviously there’s a lot of factors there, but underlying health is one of them.
Dr. Aimee: I agree. Let’s talk a little bit more about fertility and the thyroid gland, but let’s just start off with the basics. Can you just talk to us about the thyroid gland?
Dr. Christine Maren: The thyroid gland is a butterfly shaped gland in your neck. It’s a really important gland that produces thyroid hormone, and thyroid hormone controls all aspects of metabolism in our bodies. It’s relevant to fertility, menstrual cycles, blood sugar levels, weight, digestive health, mood and more.
When we talk about fertility and hormones, it regulates ovulation. With hypothyroidism you might not ovulate. One symptom of hypothyroidism could be irregular periods.
Thyroid also regulates metabolism. When we think about things like blood sugar, cholesterol, weight; thyroid is largely in charge of that.
I talk about gut health a lot, and thyroid has a profound influence on gut health. This is why people with hypothyroidism are often constipated. Hypothyroidism is also a risk factor for small intestine bacterial overgrowth called SIBO.
It is a really important gland that I think is underappreciated sometimes.
Dr. Aimee: What are some of the most common thyroid issues that you see? You did mention hypothyroidism. What are some other ones?
Dr. Christine Maren: Hypothyroidism is the most common, but it’s important to understand the root cause so that we can help address that, too.
In the United States, the number one cause of hypothyroidism is Hashimoto’s Disease, which is an autoimmune condition which causes thyroid destruction and hypothyroidism over time.
I find there are a lot of women who don’t actually know they have Hashimoto’s. In one scenario, they know they have hypothyroidism and have been on medication for that, but nobody tested their thyroid antibody levels and they don’t realize it’s caused by an autoimmune disease. In another scenario their thyroid function is actually pretty normal, but they have a lot of symptoms and a strong family history of autoimmunity, and we identify Hashimoto’s with testing early in the course of disease.
I think it’s also important to mention subclinical hypothyroidism. This is defined as a TSH above the normal range, but a normal free T4. It is so common that up to one and 10 adults are estimated to have it, and (like Hashimoto’s) it is more common in women than men. Currently many people are left untreated until TSH is really high (above 10). This is something I disagree with in the general population because I believe the benefits of treatment outweigh risks.
But, as you know, criteria for treatment in women trying to conceive is very different. If you’re working with a doctor who is familiar with this, they’ll consider treatment if either TSH is above 2.5 mIU/L, or if they have had positive Thyroid Peroxidase (TPO) antibodies — the test for Hashimoto’s Disease.
Dr. Aimee: What are some of the symptoms of a thyroid disorder? You mentioned sometimes people are struggling. Can you describe the struggles that someone with a thyroid disorder might have?
Dr. Christine Maren: Aside from infertility and irregular periods it might look like
- cold intolerance
- weight loss resistance
- hair loss
- thinning hair
- thinning of the outer third of the eyebrow
- dry skin
- sometimes muscle aches
- depression and mood changes
- episodic anxiety
- an overwhelming feeling of fatigue and exhaustion.
Overall the symptoms of hypothyroidism and Hashimoto’s can be vast and nonspecific.
Dr. Aimee: What tests should someone be sure to ask for from their doctors?
Dr. Christine Maren: The screening test for hypothyroidism is called TSH. This is a bit controversial, but it’s not a perfect test and the optimal reference range for TSH has been debated by experts for years. Some authors support an upper limit of normal of 2.5 mIU/L. However the upper limit of normal for most labs is between 4.5–5 mIU/L which means that somebody with a TSH at the higher end of the reference range, like 4, will not be diagnosed with hypothyroidism. I would argue for a tighter reference range and more personalized interpretation of this lab, because a lot of people feel pretty terrible with a TSH of 4.
In addition to TSH I find that checking free T4 and free T3 is clinically very useful. Again, these are not perfect tests, and research shows that the current immunoassay that we use can actually overestimate these levels, especially when TSH is high. This really puts the entire diagnosis of subclinical hypothyroidism in question, but that’s a story for another day. Anyhow, I’d recommend checking these labs and aiming for a free T4 of about 1.1–1.4 and a free T3 of 3.2–3.8.
Of course, I also advocate for checking Thyroid Peroxidase (TPO) and Thyroglobulin (TG) antibodies. If it is autoimmune in nature, that is an important thing to know, because I have a different approach to treat the immune response.
I also like to look at a reverse T3, because when it is really high this will prompt me to look for more systemic issues, like inflammation or environmental toxins. This isn’t the end-all-be-all of thyroid labs, so if your provider isn’t comfortable ordering this, just focus on the other ones.
Dr. Aimee: You mentioned something that I think people will wonder about. What is the difference between if you have the thyroid antibodies versus if you do not, when it comes to management of your thyroid?
Dr. Christine Maren: This is much of my approach in functional medicine. If there is an autoimmune process, there is a triad of autoimmunity: a genetic predisposition, environmental trigger, and intestinal permeability.
Intestinal permeability is a big one, and it has to do with gut health. Leaky gut is the name that goes around, but if you really look and dive into the scientific literature, it’s just about intestinal permeability. Often that’s related to an underlying gut infection like Small Intestinal Bacterial Overgrowth (called SIBO) and gluten sensitivity.
Dr. Aimee: Is there really a connection between thyroid and fertility? I know in your personal experience you felt like there was, but I think so many patients go to their doctors and sometimes they get the eye roll. Tell us more about the facts related to that.
Dr. Christine Maren: There is actually a lot of literature about this, and sometimes you really have to advocate for yourself. The thyroid plays such an important role in ovulation, fertility, and pregnancy outcomes.
Like I mentioned earlier, the literature and current recommendations from the American Academy of Clinical Endocrinology support treatment if a woman is trying to conceive and either TSH is above 2.5 mIU/L, or if she has tested positive Thyroid Peroxidase (TPO) antibodies. I’m not sure that all doctors know this, so if you’re reading, make sure these are tested and treated as needed.
One meta analysis in the British Medical Journal showed that the presence of maternal thyroid antibodies is strongly associated with miscarriage and preterm delivery, and treatment with levothyroxine could decrease those risks.
Other studies have identified that women with unexplained infertility have a TSH at the higher end of the “normal” range and benefited from treatment.
But I do think that there is a subset of women who are functionally hypothyroid and are not always identified. At the very least ask for TSH, free T4, free T3, and thyroid antibodies. And, you want to keep in mind that a patient wants to be in the upper limit of what’s considered normal when we talk about free T4 and free T3, and in the lower range of what’s considered normal when we talk about TSH.
Dr. Aimee: Moving forward, I will be adding free T3 to my panels, because right now I just do TSH and free T4, so thank you for your advice. Truly, just being in the normal range isn’t enough. You want to look at the whole pattern.
Dr. Christine Maren: It is so true. I find free T3 to be clinically very relevant, and there’s no risk really in checking this basic lab. The more data the better. But be aware that this level can fluctuate a lot for people on thyroid medication, so timing is really important. If you have a patient who is on thyroid medication like levothyroxine, I like to check their labs before they take their medication. If they are taking a Natural Dessicated Thyroid like Armour or a synthetic T3 like Cytomel, I like to check their thyroid labs 4–6 hours after they take their medication. And if somebody’s free T3 is 2.2, that’s too low. They should be around 3.2–3.8, and they’ll likely feel much better.
Dr. Aimee: What is the connection between thyroid and pregnancy?
Dr. Christine Maren: I’m glad you asked this, because it’s uber important to a healthy pregnancy. In that first trimester especially, it is important to have optimal levels of thyroid function, especially T4. The fetus really needs to see optimal levels of T4, not so much T3. It is a balance.
Hypothyroidism is associated with maternal issues like infertility, miscarriage, anemia, placental abruption, PPH, pre-eclampsia or gestational hypertension.
Complications with the baby can include preterm birth, developmental delay, lower IQ, low birth weight, fetal demise, and respiratory distress.
So I highly recommend getting your thyroid in order before you get pregnant.
Dr. Aimee: And pre-conception, how long should a woman wait to try and conceive if, she has been diagnosed with hypothyroidism? Is just making sure your TSH is normal enough or should there be a period of time where it’s normal for a set number of weeks or months before she should try? What is your advice related to that?
Dr. Christine Maren: Get it normalized. If you are switching medication, your TSH is going all over the place. Get on the right dose of medication and find out what your dose is.
As soon as you get pregnant, proteins like Thyroid Binding Globulin go up and you’re likely going to need to increase your dose by 30% (and it’s really hard to know what dose to increase by 30%, if you don’t even know your dose at baseline). It’s a big deal for a successful pregnancy.
Dr. Aimee: How often do you recommend a woman get her levels checked if she working on finding the right dose for her body?
Dr. Christine Maren: If she is pregnant, I would do it every four weeks. If she’s trying to get pregnant, probably every six weeks. It takes TSH a bit to normalize, so if you switch your thyroid medicine and take it two weeks later, your TSH won’t have adjusted yet. So four weeks at the minimum.
Dr. Aimee: And then what happens postpartum? After you’ve delivered a baby, what happens with thyroid function?
Dr. Christine Maren: A lot of different things can affect thyroid function at that point. The first thing to consider is autoimmune. I like to screen all of my patients postpartum for Hashimoto’s, since we know that pregnancy can be a trigger for autoimmune issues.
The other thing that can happen postpartum, usually about four months later, is postpartum thyroiditis. It is not as common as Hashimoto’s, but it happens. So, if a new mom is super anxious, she loses all her baby weight and can’t sleep (even though she’s super tired) and they’re hyperthyroid — it’s often because they have postpartum thyroiditis. And then they crash, and they are so tired, and a common response is to say, “Well, yeah, you’re a new mom. Of course, you’re tired.”
It’s important to be aware of these things and know what we can screen for. Often many of the symptoms of hypothyroidism are the symptoms of pregnancy or being a new mom. Yeah, it’s exhausting sometimes. It’s tiring. But looking at those labs is simple, and it’s not super expensive.
Women might be struggling postpartum, maybe even postpartum depression. Even the American Thyroid Association agrees, we should screen everybody who has postpartum depression for thyroid disorders.
Dr. Aimee: At what point should a woman have her thyroid checked after she has delivered to make sure that she’s not dealing with postpartum thyroid issues?
Dr. Christine Maren: My vote would be six weeks and six months. And then probably again at a year. But it depends on the patient.
Dr. Aimee: When you are diagnosed with something, I think sometimes people get worried that number one, they should worry, and then number two, that they need to be on something for the rest of their life. I feel like that’s the number one question I get asked, “Now that I’ve been diagnosed with this, do I really have to take this for the rest of my life?” And a lot of people do not want to.
What kind of advice would you have for patients who are worried about that?
Dr. Christine Maren: It depends. Not everybody does have to be on it for the rest of their life, but often people do. I think if you have some underlying autoimmune Hashimoto’s that isn’t addressed, yes, your dose is going to keep increasing if you never address that immune component, because there will be continued destruction of the thyroid gland. But, if you’re on the right dose of thyroid hormone, it can be such a game changer in quality of life that most people don’t want to go off of it after they realize, “Oh my gosh, it was like the lights turned on. That depression is gone or lifted, or finally I can lose the 10 pounds that I haven’t been able to lose, or my blood sugar looks better, or my cholesterol.”
There are so many benefits to optimal thyroid function. I always think about this risk-benefit ratio.
What are the risks? There is the risk of managing somebody on too much medication. There are a lot of benefits. And what do we want? I think, “What, would I rather take a thyroid hormone or would I rather take a cholesterol medication, a blood sugar medication and an antidepressant?”
Dr. Aimee: Oh, that is a great point for sure. You mentioned your own thyroid journey and you talked about something, you said, “I worked really hard.” For people who want to know what they can do that’s in their control to improve their own thyroid function, what can you share with us about that?
Dr. Christine Maren: I think nutrition and lifestyle goes a long way. What does that mean? In terms of nutrition: eating real whole foods. Focusing on nutrient dense foods, since your thyroid needs nutrients like iron, selenium, zinc and vitamin A.
I recommend a gluten-free diet for anybody dealing with autoimmune or digestive issues.
In terms of lifestyle, sleep is a huge issue to dial in. And exercise can improve the thyroid hormone receptor sensitivity, so be sure to get daily movement.
Also very important to embrace a low toxin lifestyle. If you’re wanting to become a mom, you might be already keyed into this because it’s important during pregnancy, of course. So try to get rid of some of the toxins in your home…. things like fluoride, chlorine, plastics, and heavy metals — all of those can worsen thyroid function.
But I really preach balance, and progress over perfection. And I remind my patients that small steps in the right direction add up over time.
Dr. Aimee: Everything that you have mentioned are the exact same things that I tell people that can improve embryo quality, right?
And, these things can improve sperm and egg quality, and thereby improve embryo quality, so very good advice to live by. I love how you said, “Preach balance.” There are certain patients where gluten-free is important and others where it may not be.
Dr. Christine Maren: Yes, 100%. All of this is so important for fertility.
In terms of gluten-free, I do think there are some people who are probably better off not going gluten-free. Sometimes what happens is people replace gluten with rice flours and high sugar. That stuff’s not healthy. But if you have Hashimoto’s or any other autoimmune disease, I’d recommend a gluten-free diet. This is based on research from Alessio Fassano, an MD who discovered zonulin, which is a protein release in the presence of gluten and small intestine exposure to bacteria, and worsens intestinal permeability.
Dr. Aimee: Thank you so much for all your amazing thyroid advice. Can you just tell us a little bit more about where patients and people in general can find you? And you have a podcast. I’d love for you to talk about that.
Dr. Aimee: Awesome. Well, thank you again.
Dr. Christine Maren: Thank you!
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