Dr. Nathan Fox speaks with Dr. Shari Gelber, OB/GYN, and Maternal Fetal Medicine expert regarding thyroid health during pregnancy. They discuss the hormones that are involved in thyroid health, symptoms of thyroid issues during pregnancy, the difference between hypothyroidism and hyperthyroidism, and more.
“Thyroid in Pregnancy Part One: Hypothyroid and Screening for Hypothyroid” – with Dr. Shari Gelber
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Dr. Fox: Welcome to today’s episode of “Healthful Woman,” a podcast designed to explore topics in women’s health at all stages of life. I’m your host, Dr. Nathan Fox, an OB-GYN and maternal-fetal medicine specialist practicing in New York City. At “Healthful Woman,” I speak with leaders in the field to help you learn more about women’s health, pregnancy, and wellness. All right, Dr. Shari Gelber, welcome back to the podcast. How are you doing?
Dr. Gelber: I’m good. I feel good. My thyroid feels good.
Dr. Fox: Your thyroid feels good? That’s, you don’t feel cold or clammy or anything like that?
Dr. Gelber: Nope.
Dr. Fox: Excellent. And we saw each other in person like 15 minutes ago, but we are currently in different offices doing this over the telephone, so thank you for taking time out of your busy day to talk to me, and to talk to our listeners about the thyroid. Good stuff.
Dr. Gelber: I’m excited to be here today talking about the thyroid. Like so many patients, so many doctors, everyone is excited about the thyroid in pregnancy.
Dr. Fox: It’s interesting. It comes up a lot. It is mostly not that complex, I guess in a few people it is, but I think there’s a lot of confusion about the thyroid, hypothyroid, hyperthyroid, what blood tests, who gets them, what do we do about them? And I think for today’s podcast, we’re sort of just gonna give a general overview of the thyroid, and speak mostly about hypothyroid or low thyroid, and what we do, and who needs to be screened for it, and what we do about it. And probably on the next podcast, I’m gonna have a topic for hyperthyroid, which is the opposite, where your thyroid’s too fast. So Dr. Gelber, Shari, tell us, what is the thyroid? What are we talking about here?
Dr. Gelber: So my first recollection of learning about the thyroid was when I was a medical student, and we were doing physical diagnosis, and there was this gland in the neck that we were all supposed to feel. And you had patients swallow and you were supposed to feel this thing and I could never feel it. And I thought I was gonna be a terrible doctor. So I did not start off liking the thyroid. Since then, I’ve come to the recognition that if someone’s thyroid is normal, it’s there. Like, you can see it on an imaging study if you wanted to, though we don’t routinely do that, but generally, you shouldn’t be feeling it. Although sometimes it can get bigger in pregnancy. So sometimes you can feel it in pregnancy. But it is a gland in the neck and it is responsible for secreting hormones that are important for regulating metabolism. They can impact hormones that impact brain development in children. Pretty much everything can be impacted by abnormal amounts of thyroid hormone coming from the gland.
Dr. Fox: Yeah, I think a lot of people understandably don’t really know, like, where it is or what it does because, again, it’s not in the brain and it’s sort of not in your belly, it’s this weird thing in the neck and it’s really critical. I mean, people know about it, obviously, if they have a condition or sometimes, you know, if they have like a nodule on it, you know, like a little bump and there’s a fear that it might be a cancer, and sometimes people have surgery on their thyroid. But basically, just it’s sort of like, you know, like the computer running in the background. It’s sort of like one of these things that runs in the background, and you really only know about it unless there’s something off with it. Because again, it affects so much in our body that we don’t know about. And, you know, the hormones that come out of it are not famous ones. It’s not like the estrogen or progesterone or testosterone that everyone’s heard of. It’s these weird things called thyroid hormones like T4 and T3, like the Schwarzenegger movies. But what exactly do those things do? This thyroid hormone, the T4 and T3?
Dr. Gelber: You know, one of the things that a lot of women think about a lot is that it controls metabolism in part. So when people are losing weight for some reason, a lot of times doctors will check thyroid function because if your thyroid is overactive, it’ll rev your metabolism up and make you lose weight. And the opposite is also true, like when, you know, I think everyone always hopes when they’re overweight, that the answer is their hormones or their metabolism. And when patients always say, “Oh, I think there’s something wrong with my hormones.” And you know, generally, what I’m thinking when a patient says that is, “Oh, is there something wrong with her thyroid?” Because that’s the hormone that’s probably most likely if it’s out of whack, there’s not enough T4, you might be a little hypometabolic and that can impact things like weight and impact other things like your hair, your gastrointestinal tract. Like, people who are hypothyroid might be constipated, they might get super cold all the time.
Dr. Fox: Yeah, I think I agree, and I think that a sort of a simple way to think about it is, you know, your thyroid keeps you balanced between everything going too fast and everything going too slow. And so if it’s out of balance and things are going too fast, you’ll have symptoms like your heart is racing, you’re hot, you’re sweaty, you could be losing weight. There’s other problems with that. But those are sort of the symptoms a lot of people will have. They’re, like, jittery in a sense versus the opposite, sort of, like, sluggish, I would say. You feel kind of weak, you feel kind of tired, you’re gaining weight and you don’t know why, your hair doesn’t seem right. You know, and that is sort of the low thyroid and the thyroid hormone keeps you in balance. And it’s an intricate system that keeps the thyroid hormone the right amount. Meaning you don’t want too much, you don’t want too little, and you want the right amount, which is true with most hormones. And the thing that sort of stimulates your thyroid to do that is something called thyroid stimulating hormone. It’s one of the few things in medicine that’s…
Dr. Gelber: It’s a clever name.
Dr. Fox: Yeah, it’s one of the few things in medicine that’s actually, like, correctly named, you know, for what it does. And that’s a random thing. And so the TSH, and this is one of the reasons people get confused sometimes the thyroid is the TSH is sort of what your body uses to stimulate the thyroid. And so if I check someone’s TSH value and it’s high or higher than expected, that indicates your thyroid is actually underactive because you’re needing more stimulating hormone to sort of like get it going. Or the other way to think about it is the thyroid hormone that’s made is what turns off the TSH. And so it’s sort of like a loop.
And so your TSH stimulates the thyroid to make thyroid hormone, and then the thyroid hormone tells your body, “I don’t need any more TSH.” So if your thyroid’s not making the hormone, the TSH starts going up. And so people get confused and they say, “My thyroid is high.” I always ask them, “Wait, what do you mean by that? Is your blood test high? Your TSH?” Because that means your thyroid is low. Versus if your thyroid is high, your actual thyroid is high, then it’s the opposite. Your TSH will be low. And if you’re not understanding this, pause the podcast, think about that for a second. But it’s sort of the opposite. If your TSH is high, your thyroid is low, and if your TSH is low, your thyroid could be high. And I think that does cause a lot of the confusion with this.
Dr. Gelber: I agree, that is always… Because when we are testing patients, sometimes we send all the things, we’ll send the TSH and we’ll send a thyroid hormone level. But the thyroid hormone levels can be confusing also because there’s total amount of thyroid hormone, there’s T4, there’s T3. So oftentimes we just start with the TSH. So we’re not testing for the thing we care about. The thing we care about is really how much free T4 you have because that’s what’s active. But interpreting those values can be complicated. And so we use this other thing, the TSH that goes in the opposite direction of function.
Dr. Fox: Yeah. And so in pregnancy, right, so everything we were talking about before is sort of true in everybody. In pregnancy gets a little bit more…it can be a little bit more confusing because sort of the body does make more thyroid hormone in pregnancy but the amount of free thyroid hormone does not tend to go up as much. So, like, your total T4, like you said, will be higher, but your free T4, which is the part that’s not bound to some globulin, which is the active part, does not really go up. That’s one thing that’s sort of confusing if you look at the numbers.
The second thing that’s confusing if you look at the numbers is the HCG, which is a pregnancy hormone, actually is like a cousin of TSH, they look very similar. So HCG itself can stimulate the thyroid independently, which will then make your TSH lower. And so a lot of people in early pregnancy when the HCG is high, their TSH is low, and then people think they have this new diagnosis of a hyperthyroid of an overactive thyroid. But no, in fact it’s just because HCG was thrown in the mix and you have to sort of… Like, that’s what’s gonna make up the difference and why the TSH is low.
And the third thing that’s sort of a little bit complicating is, as you said in pregnancy, the thyroid tends to grow and so people’s thyroids are frequently enlarged compared to when they’re not pregnant. And that’s not abnormal, that’s not a concern, but it’s a new finding that wasn’t there before. And all of this sometimes leads to misdiagnosis or confusing diagnoses in pregnancy. But generally, this is something that we all know about and so we don’t really make much of any of those things.
Dr. Gelber: Yes. And like, you know, one of the most common complaints people have early in pregnancy is nausea and vomiting. And that is due in part to high levels of HCG, but those high levels lower the TSH, they can make you a little bit hyperthyroid, and hyperthyroid can also have some nausea and vomiting. And so it can be difficult if you’re not thinking it through or you didn’t know a patient was pregnant, like, they come in, they’re vomiting, their TSH is very low, you could think that they’re hyperthyroid when really it’s just a normal adaptation to pregnancy.
Dr. Fox: Yeah. And so that is one of the first places where things get a little bit confusing and sometimes misdiagnosed. And I think that hypothyroidism, where the thyroid is low, is another situation that, you know, sometimes people get a lot of differing opinions on whether they have it, they don’t have it in pregnancy, do they need to be treated? Do they not need to be treated? Do they need to be screened for it or not? And we’re definitely gonna get into that because I know that it’s one of the things you’re passionate about, as you told me, we may just give you five minutes to just go off, you know, at some point during the podcast and rant and rave about it, which is great. I mean, that would be for very good entertainment purposes and educational.
But let’s start with just hypothyroidism in general. I think, worldwide…because people sometimes might google this and find different reasons. In the world, a lot of hypothyroidism is due to an iodine deficiency. The body needs iodine in order to make the thyroid hormone. And so if you have an iodine deficiency you could have low thyroid hormone creation and excretion. But in the U.S. we pretty much fortify things like salt with iodine. So we don’t tend to have a lot of iodine deficiency in the U.S. And so if that’s the case, how would people with normal iodine intake get hypothyroid, get a low thyroid?
Dr. Gelber: Well, so I’m gonna take a step back actually because I think about everyone in the U.S. being iodine-sufficient and they probably are, but it used to be that everything was fortified with iodine. Like, salt was the most basic thing that was fortified with iodine. And now for some reason that is not always the case. I was looking in my cabinet the other day because a friend had to be on a no-iodine diet, and I found out that my salt wasn’t fortified, and I didn’t even know that was a thing. So, I think people are now more careful about what goes on with food and a lot of people are on restrictive diets and I think it probably is worth thinking about iodine, although I don’t think I’ve ever seen iodine deficiency in the U.S. And prenatal vitamins are supplemented with iodine also.
But mostly in the U.S. when people are hypothyroid, it is from either an autoimmune condition, like lots of women have autoimmune conditions, women are much more likely than men to be predisposed to autoimmune disease. And autoimmune thyroid disease is one of the most common conditions that women have. So the most common kind that we see is something called Hashimoto’s Thyroiditis. There’s something else called Graves’ Disease, which more typically patients get hyperthyroid first, and then the thyroid runs at full tilt for a while, and then it’s had enough, and it’s done all of its work for your life. And then you can become hypothyroid after having Graves’ Disease. Sometimes, people have their thyroid removed, they have thyroid cancer, they have thyroid nodules removed. So, there are a lot of ways people can get hypothyroid, but the most common that I see in my patients is from Hashimotos.
Dr. Fox: Yeah. And Hashimoto, that’s the long word and it’s got a lot of…you know, that’s a lot of marketing for Hashimoto for that condition. Like getting your name on that condition is really…that was…I don’t know how much he or she had to pay for that, but it was really…that’s impressive, that’s a good one. You know, a lot of people have it, they talk about it. “Do you have Hashimotos? Do you have Hashimotos?” It comes up a lot, more so than a lot of other conditions. So that’s good, you know, for Dr. Hashimoto. Why would…let’s say someone’s hypothyroid, aside from their own symptoms, right? Because it’s not pleasant to feel cold and sluggish and gain weight. What would be the concern of someone who is hypothyroid in pregnancy? And some of them, the theoretical concerns let’s say because they’re not always the case. But what would be the potential concerns?
Dr. Gelber: So for people who have true hypothyroidism, not a borderline value or we’re not sure, but people who really have very low levels of T4, very high levels of TSH who are legitimately hypothyroid, there are significant pregnancy concerns. There’s an increased risk of the thing I think about the most, which is preeclampsia, which is high blood pressure in pregnancy, but also preterm birth, stillbirth. A lot of people are very concerned that untreated hypothyroidism can cause neurodevelopmental problems in children, and lack of thyroid hormone in pregnancy and in the neonatal period is associated with neurodevelopmental problems. All babies as part of their newborn screen have their thyroid levels checked.
Dr. Fox: Right. And that’s checking the babies for their own thyroid because they have to take over after birth. But the concern is also, since the babies don’t really have actually any thyroid in the first trimester and beginning of the second trimester, and the function is sort of variable, the thought is that the baby needs the mother’s thyroid hormone in order to have all this development in the first half of pregnancy. And if the mother really truly doesn’t have enough of it, it can affect the baby’s development even before the baby is born and screened for it. And that’s where a lot of sort of the fear of thyroid in pregnancy comes from, this concept that low thyroid in the mother can lead to neurodevelopmental outcomes just from the lack of exposure to thyroid hormone in pregnancy. That’s true for people who are overtly hypothyroid, like you said, the low T4, the high TSH, you know, symptoms, and the whole thing.
And so if someone has that condition, we absolutely give them thyroid to make them…the word we use is euthyroid, that’s E-U-thyroid, which means like normal, like sort of middle of the road. And actually, it’s not that hard. We give them thyroid replacement and then we check their blood levels and they either need more, they need less, usually, for pregnancy, they need a little bit more. And it’s not that complicated as long as you know they have it and you treat it. And then you can, you know, avoid all of those consequences because you basically make them like everybody else, you just replace a thyroid hormone they don’t make on their own. So the real controversy is not related to treatment of hypothyroidism in pregnancy. That is, like, very straightforward stuff. So where is the controversy, Dr. Gelber? Here we go.
Dr. Gelber: Well, the controversy is something called subclinical hypothyroidism. And subclinical hypothyroidism, before we were talking about the TSH being a marker of something, and then the T4 being the actual thing that was affecting function. And so subclinical hypothyroidism is when the TSH is a little bit off, it’s not in the normal range but your T4, your functional thyroid level is normal. So, you know, your first thing is that it looks like there might be a problem, but then it turns out you have all the thyroid hormone you theoretically need.
Dr. Fox: And so why is that controversial?
Dr. Gelber: It’s controversial because hypothyroidism is associated with things that we all care about deeply, like adverse pregnancy outcomes and miscarriages, and people have this… You know, it was a good idea many years ago to say, well, maybe these adverse pregnancy outcomes that happen to people who are completely euthyroid, like most people who have preeclampsia, most people who have preterm birth, most people who have miscarriages, their thyroid is perfectly fine. But it was a good idea to say, well, we know these things happen in people with thyroid disease, maybe the subclinical hypothyroidism can cause these adverse pregnancy outcomes. And if we treat people, we just give them a little bit of thyroid hormone, they’ll do better. And that’s being studied, and there have been some small studies that have shown a benefit.
But the larger studies, the studies that I think are done better really haven’t shown much of a benefit on any of these outcomes. Not decreasing miscarriages, not changing cognitive function in children, and it’s something that we all wanted to work, like, it was such an easy fix, like thyroid hormone is safe, it’s not expensive. It would’ve been great if we could have given medication to patients to improve their pregnancy outcomes, but the data hasn’t really panned out. But a lot of people are still screening people specifically looking for subclinical hypothyroidism so that they can treat them.
Dr. Fox: Yeah, I mean, it is… Again, there it’s such a controversy because, you know, like you said, that the thought process isn’t bad. It’s like okay, we know if there’s a big problem, if there’s a big issue with the thyroid, it can cause big problems and if we treat it, we fix it. Right? Great. Like, okay, what if there’s a small problem with the thyroid, will it cause small problems or will it cause big problems at a small frequency? And if so, if we treat it, will we sort of reduce it? And it hasn’t been shown to help. It’s almost like… And it hasn’t been shown to help, like you said, in the big studies.
And so it’s sort of like we know diabetes is a problem and if you treat diabetes, it’s a good thing. But what if someone’s sugar is like slightly elevated but it’s not diabetes, is it a good thing to treat it? Is it not a good thing? Well, it’s not exactly the same situation, but it’s not always that if something is bad, that a little amount of it is a little bad, it really doesn’t always work like that. And it has not seemed to pan out for thyroid. And so, like you said, a lot of people walk around with this slightly elevated TSH but a normal thyroid function, they don’t really have symptoms. And they end up getting treated, and they get blood tests all the time, and they’re sent to endocrinologists, and they have all this follow up, and they’re told, you know, “If you don’t take your thyroid, it’s gonna be a problem for the pregnancy, a problem for the baby,” and then they’re all worried. And it’s a lot when it seems that they don’t need any of it. What’s the downside? Like as far as we know, is there harm to giving someone a very small dose of the thyroid medication if they’re borderline or subclinical hypothyroid?
Dr. Gelber: I don’t know of any harm. But whenever we take a medication, most people don’t wanna take medications they don’t need, crazy things could happen. You could get the wrong dose from the pharmacy, like something could happen. And I think it’s bad for people’s mental health to be given diagnoses that they don’t really have. Like, a lot of people have enough problems without being told they have a medical condition that they don’t really have, or being told they should take a medication that they don’t really need. Like certainly taking too much thyroid hormone could be dangerous, but the low doses that are generally given to people, 25 micrograms, 50 micrograms, probably isn’t gonna cause any harm in pregnancy. And a lot of these studies where they’ve looked at supplementing patients with subclinical hypothyroidism, they haven’t found benefit but they also haven’t found harm.
Dr. Fox: Yeah, I agree. Like, if someone comes to me, and they’re already on this low dose of thyroid, and I go back and I sort of investigate why, and I find out that for whatever reason they were checked, and their TSH was a little bit high, and their free T4 was normal, and they have this subclinical, and whoever saw them said, “Take this thyroid.” I’ll usually tell them, “Listen, I don’t think you need this but, you know, whatever, like, I don’t think it’s such a big deal to be on this dose if it’s gonna make you more anxious going off the thyroid, then I’m fine leaving you on.” But someone’s like, “Wait, I can go off this?” I’m like, “Yeah.” Like, “All right, great.” And they just go off it, we just check their thyroid again to make sure it’s truly subclinical or better, and fine, we’re done. So I agree, but it is a lot because the next sort of step in the evolution of trying to fix a problem is, okay, well, now if I’m gonna say that treating subclinical hypothyroidism is valuable, we don’t know if someone has subclinical hypothyroidism, so now we have to screen everybody.
And so now it leads to the recommendation or there was some certain people recommending that every person when they’re pregnant should have thyroid function checked at the beginning of pregnancy. So you can pick up those 2%, 3%, 4% of people who have the subclinical so that you can then treat them. And now we’re like taking it even another step, like, more expansive. Not only are you just treating the people who happen to have subclinical hypothyroid, now we’re gonna start looking for it in everybody. And that really changes everything because now it’s not just every now and again somebody happens to get a diagnosis, and they happen to get treated and whatever. Now what you’re talking about millions and millions of people getting screened, and a lot of them are now told they have subclinical hypothyroid and they’re all treated. What do you say about that?
Dr. Gelber: I think that the data doesn’t support it. And I could be wrong about this. I know that the American College of Obstetrics and Gynecology does not think we should be screening young women without signs of thyroid disease for overt or subclinical hypothyroidism. I’m not sure what the American Thyroid Association has to say about that, because sometimes recommendations from different professional organizations differ. But I don’t believe they recommend treatment of subclinical hypothyroidism. So the real thing with screening is should you be screening for overt thyroid disease?
Dr. Fox: Yeah, I mean, there were pretty big studies like when you said the data didn’t pan out, there were a couple of really large studies because this was a hot question for a long time, and people debated this and so they, “All right, let’s do a study. Let’s, you know, sort of screen half the people, you know, randomly, screen half the people for thyroid, and not screen the other half. And in the half that were screened, if they have this subclinical, let’s treat them and let’s look to see if this sort of strategy of screening and treating improves outcomes overall in the whole group of patients and their children.” And it didn’t. Right? So essentially, as compared to not screening routinely, I mean you screen people you think need to be screened for whatever reason, they’re diabetics, or they have a family history, or they have symptoms like whatever it is, you use your judgment essentially versus doing everybody. And then the other arms that screen everybody, no difference. And that’s in terms of pregnancy outcomes and they looked at these children I think at age five to seven, and there’s really no difference…
Dr. Gelber: Yeah, they looked at neurodevelopmental outcomes and, you know, because that’s one of the arguments is you wanna do this to protect the child’s brain, but didn’t pan out.
Dr. Fox: Yeah. And so based on those studies which were predominantly done through sort of, you know, departments of obstetrics and gynecology, like they’re sort of pregnancy-related studies, they weren’t done by the endocrinologists, based on those studies, pretty much all of the, like, OB-GYN, maternal-fetal medicine, all those societies do not recommend or actually recommend against screening everybody for thyroid. Now with that said, like we were talking about before, it’s not that it’s specifically harmful to screen people and then treat them if they’re subclinical, it just seems to be unnecessary, and to start doing blood testing, and counseling, and treating, and diagnosing on all these people, like you said, may not have a direct, like, measurable downside. But there is a downside logistically, cost, you know, sort of resources also in terms, like you said, people’s own impression of themselves and their own fears and anxiety when they have a diagnosis versus they’re told they’re fine. And that is relevant but it is a big thing because not everyone agrees, and not everyone follows the recommendation not to do it.
And some people get screened. And again, I’m not disparaging people who do, like, people make decisions that are against guidelines all the time. It doesn’t mean they’re bad doctors or anything like that, but sort of for listeners out there who are pregnant, it’s, you know, “Was I screened for a thyroid? Was I not screened for thyroid? If I have this diagnosis, was it sort of based on the fact that I really have hypothyroid, or was I subclinical? And was the recommendation to treat sort of framed in a way that it’s protecting my baby, or just sort of, like, well, maybe it’ll protect?”
And, you know, again, it’s just one of these things to think about, predominantly because it’s interesting. Again, I don’t think the stakes are so high in either direction here, but it is really fascinating. Now also, there is this concept of some people getting their thyroid function checked before pregnancy, and then finding a value that’s normal when you’re not pregnant, but sort of slightly high, the TSH level that is slightly high for when you are pregnant and being supplemented in preparation of pregnancy. So, what’s going on there, and what do you think about that?
Dr. Gelber: Well, so a normal adaptation to pregnancy is that in early pregnancy, your TSH goes down, your free T4 goes up. Like these are things that happen and, you know, some of that we talked earlier about the beta HCG, and these are things that are supposed to happen. And we have pregnancy cutoffs. Ideally, any lab that you are sending blood work to for a pregnant patient will have a pregnancy, a trimester-specific value for TSH and T4 because the numbers in pregnancy are different than outside of pregnancy.
And so it’s not surprising at all if someone’s TSH pre-pregnancy is higher than a normal pregnancy level, and once they’re pregnant, TSH goes down. That TSH not going down is something that’s associated with miscarriage. And so sometimes people look at a TSH pre-pregnancy and they say, “Well, this is in the normal range, not for pregnancy, but it wouldn’t be normal if they were pregnant. So I’m gonna amp the patient up and I’m gonna give them thyroid hormone to lower that TSH so that the TSH doesn’t cause the miscarriage.” And I think it’s sometimes a lack of understanding of how all of this works, and that if the TSH doesn’t go down and the patient has a miscarriage, it may not be that there was a lack of thyroid hormone, it may just be a sign that there was something wrong with the pregnancy to begin with.
Dr. Fox: Right. Meaning a “bad pregnancy” will not have the associated changes in the TSH as opposed to the TSH somehow affecting the pregnancy and causing a miscarriage.
Dr. Gelber: Right.
Dr. Fox: Sort of like progesterone, we have the same thing. There’s, like, this idea that we should supplement progesterone in early pregnancy, and most of the studies have shown it doesn’t work because a low progesterone doesn’t typically cause a miscarriage. It’s a bad pregnancy causes a low progesterone, and so you can give all the progesterone you want, the pregnancy’s not gonna be any better.
Dr. Gelber: Right. And I think, you know, people who do this, I think they’re afraid of missing a critical window. Like, what if it doesn’t go down? What if something happens? Like I think everyone is acting in good faith, but I like acting in data.
Dr. Fox: Yeah. No, I hear you. And that’s another thing, I’ll see people and they’ll say, “Oh I’m hypothyroid.” I’ll be like, “Oh, what was your number?” And they’ll be like, “Three.” I was like, “When you’re not pregnant?” They’re like, “Yeah.” I’m like, “That’s normal.” They’re like, “Well, that’s not a normal number for pregnancy.” I’m like, “But you weren’t pregnant when they drew your blood. Like, that is how it’s supposed to be when you’re not pregnant. And it would go down when you got pregnant.” So, it is sometimes…again, it’s along the lines of these people getting treated for things that isn’t actually wrong. It’s probably not crazy dangerous but it’s really…it seems to be quite unnecessary.
Dr. Gelber: Yes, I have confidence in the pituitary. And then along these lines when we’re talking about subclinical hypothyroidism, the other thing I think of in the same basket are people who are euthyroid who have thyroid antibodies, like TPO antibodies.
Dr. Fox: Right. Those are the antibodies…
Dr. Gelber: Because there’s controversy with that too.
Dr. Fox: Right. Those are the antibodies that you would find in someone with Hashimotos that these are the antibodies that can cause hypothyroidism, and we call that Hashimotos. And you’re saying we find the antibodies but their thyroid is normal. So sort of like screening for Hashimotos without having a thyroid problem.
Dr. Gelber: Right. So sometimes people send off antibodies for, you know, reasons, maybe the patient has other autoimmune conditions, maybe you’re interested, maybe you have a read like you just send them off with the thyroid hormones because you think that’s what’s going on, and you don’t wanna make the patient keep coming back for more labs. And sometimes you get patients whose TSH is normal and their thyroid hormone is normal, but they still have these antibodies. And the antibodies are pretty common in reproductive-age women, and they are independently associated with adverse pregnancy outcomes like miscarriages.
The problem is that there’s not a treatment to prevent those outcomes. So there have been big studies of patients with these antibodies, and giving patients thyroid hormone because people thought that would help, and it didn’t decrease the miscarriage rate. And so then you’re sort of stuck with a patient with antibodies, and now they’re at risk for something but we don’t have a treatment for it. And I think that is hard for people.
Dr. Fox: Yeah. And also because when you say that having the antibodies is associated with miscarriage risk, that doesn’t mean that we know the antibodies themselves cause the miscarriage. It could be that some underlying condition causes someone to have a miscarriage and causes them to have antibodies. And so fixing the antibodies or doing something about the antibodies isn’t really the issue. It’s sort of like a higher level problem that we either don’t know about or maybe it’s something just, you know…like a simple way to think of is maybe as you get older, the chance of having these antibodies goes up. And as women get older, they have a higher chance of miscarriage. And so someone could misinterpret the data to say it’s the antibodies when it’s really the age. I’m not saying the studies did that, I’m saying that’s like an example of something that could be what we call confounding when they say antibodies are associated with. Well, it doesn’t mean they cause it. That’s part of the issue.
Dr. Gelber: Right. The antibodies are also associated and this probably is causative with thyroid disease later in life, like postpartum thyroiditis. So certainly if someone knows they have the antibodies, it’s a pertinent part of their medical history, I probably would think about it more if they’re tired postpartum, if something is going on postpartum, if things aren’t right, or, you know, it’s a piece of information for their regular medical doctor so that in their life, they’re screened appropriately for thyroid disease.
Dr. Fox: Right. Right.
Dr. Gelber: I don’t routinely send those antibodies for patients.
Dr. Fox: And so how do you counsel patients who come to you with various issues, and part of their workup that has already been done prior to seeing you is a TSH and thyroid antibodies? How do you address it in general? Do you tell them like ignore it, or is it based on the numbers or other?
Dr. Gelber: You know, I try and find out what information the patient has. I try and educate them about what we’ve discussed. But I also think it is very important to be kind and understanding, and understand that patients get different information from different providers. And so like, you know, I’m a big records person so I will go digging back and figure out, “Well, why did someone send this?” And maybe there was a reason, maybe this is a family with a lot of thyroid disease, maybe this is a patient who has other autoimmune things. But if it’s truly something isolated like just an isolated abnormal TSH, or isolated elevated thyroid TPO antibodies, I generally tell patients my recommendation is that they not be treated for this. But if someone feels very strongly that they be on a low dose of thyroid hormone, you know, if they have been counseled and they understand how I feel about it, I think that’s reasonable. Like I don’t think thyroid hormone at low doses is dangerous to patients.
Dr. Fox: Yeah, I think that’s a really good way to think about it and I’m very similar. Doctors disagree on things all the time and that’s fine. Like totally reasonable. Two very conscientious smart people can look at the exact same situation and think different things about it, and that’s okay. I tend to try to go with the data, like you said, in terms of making my recommendations, but you also have to consider the stakes, you know, with this if you’re seeing someone and one doctor said to do A, and I think we should do B, a lot of it depends on how different A and B are, what is the risk of one versus the other. So if A versus B is whether you take 25 micrograms of Synthroid or not, like whatever, you know, they say yes, I say no, I’m not gonna make a big deal about it because like you said, it’s not likely to be very harmful.
Now, obviously, if they recommended something a little bit more out there, you know, that I thought was actually dangerous or had a higher chance of risk, I’d, you know, be a little more firm and say, “Listen, I really, really think this is a bad idea and here’s why,” and, you know, go into it. And that does happen. But with thyroid, not that much, fortunately. The times when I, you know, sort of am a little more forceful is if someone…again, I’ll get to this in the hyperthyroid podcast, but if someone’s put on antithyroid medicine because someone thought their thyroid was a little too high and they’re early in pregnancy. I’m like, “Well, that may be dangerous, like let’s…you know, we gotta back off that.” But for what we’re talking about, taking a little bit of supplemental thyroid versus not, it’s probably not necessary for most people. But again, it’s not anything to go too crazy about generally.
Dr. Gelber: Right. And I agree with you about that. Like pregnancy is a slightly hyperthyroid state. It is a hypermetabolic state, especially the beginning of pregnancy. And so being on a little extra thyroid hormone isn’t likely to be harmful. Being on medications that suppress thyroid function can be dangerous. And so that is also where I draw the line. Like I’m okay with a little extra Synthroid, but I’m not okay with an unindicated [inaudible 00:40:27]
Dr. Fox: Yeah. And then again, for someone who truly has hypothyroid or they’re being treated for the subclinical, it’s really very straightforward. Some people do follow with endocrinologists, but it’s rarely sort of necessary in a sense as long as someone is checking your thyroid levels. And usually, that’s just the TSH and maybe the free T4 at the same time, but usually just the TSH every, whatever, two to three months and maybe every month if you’re changing your dose around, just to make sure we’re getting the dose right. For most people, that’s very straightforward and does not require a lot of thought. I tell people this is like in medicine, like one of the easiest things we’re gonna do, fortunately. So it doesn’t require a lot of brain power in my end as long as we remember to check it. That’s really the thing for someone who has overt hypothyroid not to forget to check it, because frequently, over the course of pregnancy, the dose does have to go up during pregnancy.
Dr. Gelber: Yeah. Like so some people preemptively increase levels and check numbers, and some people just get more frequent blood testing and adjust in response to the numbers.
Dr. Fox: Yeah. Excellent. All right, Shari, thank you for coming on to talk about the thyroid, the hypo side of it. I believe Dr. Doe is gonna come on to talk about the hyper side of it. And my guess is I’ll probably drop these back to back. So my guess is that’ll be for next week, but I guess you could listen to the intros to confirm that.
Dr. Gelber: Okay. Well, thank you for having me.
Dr. Fox: Always a pleasure. Thanks, Shari.
Dr. Gelber: Okay.
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