FAQs about Thyroid and Pregnancy
If you’re newly pregnant (or want to get pregnant), congratulations! If you have thyroid issues, you probably have lots of questions about how to manage your medication for optimal outcomes for you and your baby. Below, Dr. Stracks answers many of the most commonly asked questions about thyroid and pregnancy.
Q: I’m pregnant and have thyroid disease. What do I need to know or do?
A: First of all, congratulations are in order. That’s great!! I’m excited for you. Over my 12 years in practice, I’ve seen hundreds of women with thyroid disease deliver healthy babies, and I’m confident you will as well. If you’re a current patient of mine, go ahead and contact us and we’ll check your thyroid levels and adjust your medication as necessary. If you’re not a current patient but would like to be, please reach out as well, and we’ll get you started with a monitoring protocol for the entire pregnancy and postpartum period.
Q: I’ve read that I should increase my thyroid medication by 20% right away. Is that true?
A: No, not necessarily. My reading of that recommendation (from the American Thyroid Association (ATA) is that the ATA assumes that women don’t have a good sense of where their levels are before pregnancy and so is recommending an increase in dose, just to be safe. My experience with my clients is that almost all of them know precisely where their levels are while they’re trying to get pregnant, and so most of them have optimized dosing in the months leading up to conception. Rather than assuming that you have low levels, I recommend getting labs done right away to assess whether your levels have changed during early pregnancy and then changing doses only if indicated by the labs or your clinical condition.
Q: But the ATA says that thyroid medication requirements increase by 25-50% during pregnancy. Won’t I need more medication over the course of the pregnancy so I might as well start increasing now?
A: Like many aspects of thyroid management in the United States, many recommendations, like those of the ATA, are based on what’s written in textbooks. In reality, though, very few of my clients’ thyroids have read the textbooks. I’ve learned over my years in practice that every single person is an individual, with their own individual needs; no one is “average,” and thus it doesn’t make sense to make an “average” adjustment. Everyone should get their medication adjusted based on their own individual needs.
My clinical experience is that 70% of my patients need no adjustment to their medication during pregnancy. Their labs stay stable, they feel good during the pregnancy, and, though we monitor monthly, there’s never a need to change doses. About 25% of my patients need small adjustments (up or down, interestingly) that we make as the pregnancy continues. About 5% of patients need significant increases in their dose of medication. Those patients are identified through the lab work; often, though not always, these women have gotten pregnant through IVF and the hormones associated with that process are likely what drives the need for higher doses. I’m very comfortable monitoring and changing doses even in those cases, and all of those clients have had uncomplicated pregnancies and now have healthy children.
Q: I take T3-based medication—either liothyronine and/or desiccated thyroid—and I’ve been told I can’t do that. Is that true?
A: That’s one of the biggest controversies during pregnancy, so I’ll be expansive in this answer. The short answer is that no, it’s not true that you can’t take T3-based medication. That, as you know, doesn’t stop practitioners from saying so.
The medical system in the United States (and probably other countries as well) is fairly biased against T3 medications to begin with. As I mentioned above, though, every single person is an individual who either does or doesn’t need T3 to feel well. Thus, even if, on average, you could do just fine with T4 medication (and that’s debatable in my mind), if you feel better with T3 in your system, that’s a perfectly reasonable and rational treatment for you.
The additional controversy in pregnancy comes from ancient studies that showed that T4 crossed the placenta while T3 did not. That led to a number of recommendations from the ATA and others to use T4 only (e.g., levothyroxine) during pregnancy. However, the claim that T3 doesn’t cross the placenta isn’t actually true. Initially (pre-1980), it was thought that no thyroid hormones crossed the placenta and so women needed to take iodine during pregnancy to assure appropriate thyroid function in the growing baby. It turns out that the initial studies that showed that T4 was able to cross the placenta were not inaccurate, only incomplete. Over time, advances in technology have shown that T3 does cross the placenta as well and that the placenta is rich in deiodinases that turn T4 into T3 for the developing baby’s circulation. A nice review article for those who are interested can be found here.
The recommendation that women take only T4-based medication during pregnancy is thus based on outdated research and science as well as outdated logic. Of my clients, 99% who are taking T3 are taking T4 as well. Even if T3 was a non-factor during pregnancy (which science says at this point is not true), there are two checks in place: there is plenty of T4 in women’s circulation even when also taking T3, and I’m constantly measuring levels during pregnancy and adjusting medication doses as needed.
Additionally, both liothyronine and desiccated thyroid are considered Category A drugs during pregnancy, which means that both clinical experience and well-designed trials have shown no adverse outcomes to taking those medications. My own clinical experience supports this; I’ve seen hundreds of women take these medications during pregnancy without seeing any adverse outcomes or risks to the mothers or the babies.
Lastly, for those who are still skeptical, this case study was recently published of a woman who had two healthy pregnancies taking T3-only medication with very, very low levels of T4 during the entire pregnancy. Cases such as these, combined with evolving research and clinical experience, continue to challenge the currently accepted dogma that T3 is not safe to use during pregnancy.
Once again, though, keep in mind that evolving research and experience won’t necessarily keep practitioners from quoting outdated studies and theories to convince you otherwise.
Q: That all sounds reasonable, but why do other practitioners tell me differently?
A: That’s a good question. I wish everyone in the medical field was on the same page, but I know from experience that that’s not necessarily true. I’ve witnessed other practitioners saying horrible, hurtful, untrue things to my patients during pregnancy; there’s no need for that, and yet I know that it happens.
Keep in mind that the average length of time for medical science to be translated into clinical practice is about 20 years. Physicians and practitioners are busy and frequently unable to keep up with scientific advantages. Many practitioners are working with outdated models of medical care without realizing it, and medical training encourages dogmatism over cooperation, for better or worse.
Most of my clients find that if they hold the line with their practitioners and let them know that someone else (me) is monitoring and following their thyroid function, then they back down and agree to that arrangement. If there’s more pushback or the rare occasion that they insist you take levothyroxine or not see them during your pregnancy, let me know and we’ll sort out what to do so that you can be monitored as safely and as effectively as possible throughout your entire pregnancy.
Q: Someone told me too much thyroid hormone is bad for my baby. Is that true?
A: Yes and no. I’ve found over time that my patients tend to feel best when T4 levels are in the bottom part of the normal range and T3 levels are in the top part of the normal range. For a variety of reasons during pregnancy, both T3 and T4 can rise, but usually not outside the normal range or just outside the normal range. I have not seen any complications in pregnancy with those lab values.
There are some studies showing that high levels of thyroid hormone in pregnant mothers can be detrimental to the developing fetus, but these studies are old and somewhat contradictory. I never like seeing thyroid hormone levels far outside the range of normal, and if I see that in someone during pregnancy, I usually will reduce the dose.
Also, keep in mind that T3 levels are standardized to be taken 24 hours after the last dose of T3 containing medication. Since most OBs do not know that, frequently labs are taken shortly after the dose of medication and the lab values are quite high. This is a lab issue, not a medication or hormonal issue, but often this will raise red flags for OBs even though there’s no safety issue present.
Q: How will you manage my thyroid disease during my pregnancy?
A: Over the years, I’ve adjusted our pregnancy protocol so that it makes the most sense for you and the most sense for our practice. Currently, we charge the equivalent of one new patient appointment, which includes a short visit at the beginning of pregnancy, a short visit halfway through the pregnancy, and monthly monitoring of labs throughout the pregnancy. This provides the best balance of supervision of you and your lab values and low cost by not making you schedule an actual appointment each month.
The two appointments allow for face-to-face time so that all your questions can be answered. The monitoring is normally done through our staff who will reach out after each lab draw and find out how you are doing.
About 5% of pregnancies involve complications such as levels being off, patients not feeling well, OBs alarmed by the use of T3 medication or other issues. I do my best to manage that through the protocol so that there is no extra fee; occasionally we will set up extra appointments in particularly complicated situations that require more extensive face-to-face communication. That occurs less than 1% of the time.
Q: I’m trying to get pregnant. Does my TSH have to be lower than 2.5 to get pregnant?
A: Yes. My observation has been that TSH levels higher than 2.5 are associated with higher levels of miscarriage, and studies seem to support that assertion as well. In general, if your TSH is higher than 2.5, I would work to lower it, probably by raising or adding medication.
Note also that in addition to miscarriage, some clinicians would say that a TSH of over 2.5 has risks for the developing fetus; however, I have not found that to be true. In the fairly recent past, any TSH under 10 was considered normal and my sense is that developmental issues related to low thyroid are archaic—that is they were far more common hundreds of years ago before we really understood what a thyroid was or how it worked—than they are today. In Western, developed countries where we’re monitoring thyroid regularly, I think the risk of developmental issues in babies is essentially zero. I’ve certainly never observed this happening and I have not heard of any cases outside my practice, either.
One of my patients was successfully treated with desiccated thyroid when she got pregnant and was doing fine—until her OB insisted that she switch from desiccated thyroid to levothyroxine during the pregnancy because it was “safer.” Her TSH immediately went up to 50, and we couldn’t get it back down during the pregnancy no matter how high we raised her dose. The TSH never came down into single digits for the rest of the pregnancy—and her baby is fine.
Bottom line, I would, if I were you, work to get your TSH level down close to 1 in preparation for getting pregnant but I wouldn’t spend much time once you’re past the first trimester worrying about how your thyroid function is affecting the developing baby.
Q: Are there any considerations I should know about in the postpartum period?
A: I like to check labs about 6 weeks postpartum to make sure levels are stable and nothing has shifted in terms of thyroid function since delivery.
The three main issues I like to monitor are:
1) postpartum depression, which is rare these days but certainly can happen,
2) milk production, which can be affected by low thyroid function, and
3) hyperthyroid symptoms, which can also happen in the postpartum period.
As I said previously, about 25% of my patients need a dose adjustment during pregnancy and some of those patients need their dose adjusted back shortly after delivery. Additionally, my patients with Hashimoto’s Disease can occasionally have a flare that results in hyperthyroid symptoms, so symptoms like anxiety, jitteriness, rapid heart rate, heart palpitations, and so on should be brought to my attention right away.
Most of the time, the postpartum period goes smoothly and the routine check at 6 weeks is fine (and also lets me see pictures of and/or meet your new baby ☺), but occasionally issues will pop up and we’ll check labs sooner to head off any larger issues that may be developing.
Q: I’m not currently a patient of yours, but I’d like you to manage my thyroid while I’m pregnant. How can I make that happen?
A: I’d be happy to help you have a safe and comfortable pregnancy. Please reach out to our new patient coordinator, Alexandra, through our website Cormendihealth.com, send us an email at info@cormendihealth.com,or call us at 312-489-8890. Our staff will be happy to get all your information and set up an intake appointment with me to get started. If you’re pregnant already, we’ll work to get you in right away to regulate your thyroid function as soon as possible.
If you have more questions about thyroid treatment options during pregnancy or want Dr. Stracks to manage your care, schedule a consultation. He will create a plan to make sure you have a safe, healthy, and comfortable pregnancy.