Getting pregnant with hypothyroid: Hypothyroidism and infertility: Any connection?
Can I Get Pregnant With Hypothyroidism?
Undiagnosed or poorly managed hypothyroidism is a major reason for infertility, but you can take steps now to improve your chances of getting pregnant.
Hypothyroidism is when your thyroid gland doesn’t make enough thyroid hormone. Thyroid hormones regulate your metabolism, which affects how your body uses energy. Thyroid hormones are also involved in the regulation of your menstrual cycle. When thyroid hormone is at optimal levels, the body may skip ovulation, which leads to a missing period. Pretty difficult to get pregnant without ovulating, since the egg is key in conception.
But as someone with hypothyroidism, I am proof that you can still get pregnant. In this article, I will share with you what you need to know about hypothyroidism and pregnancy, including the steps you can take to improve your chances of conceiving.
Causes and Symptoms of Hypothyroidism in Women
The causes of hypothyroidism are different for each woman, but the number one cause of underactive thyroid in women is Hashimoto’s thyroiditis.
Hashimoto’s is an autoimmune condition where the body mistakenly attacks the thyroid gland. Autoimmunity means that the immune system is attacking itself. With Hashimoto’s, the body produces antibodies that flag the thyroid for destruction. These antibodies are anti-thyroid peroxidase (TPO) and anti-thyroglobulin (TgAb). Once flagged, the immune cells attack and destroy thyroid cells.
The destruction of thyroid cells leads to a decrease in thyroid hormone production, as there are not enough functioning cells to produce the necessary amount of hormones. Over time, enough thyroid tissue is destroyed and the gland can no longer make enough thyroid hormone, resulting in hypothyroidism. It’s generally at this time that medication becomes necessary.
The causes of Hashimoto’s thyroiditis are not fully understood, but it is thought to be due to a combination of genetic and environmental factors. Gut health plays a significant role (as you’ll learn below), and it is thought that a compromised gut lining may allow bacteria and toxins to enter the bloodstream, which triggers an autoimmune response.
It can take years for Hashimoto’s to show up in standard thyroid labs, so it’s always critical to test for thyroid antibodies (anti-TPO and TgAb) even if your TSH is in the “normal” range if you have any thyroid symptoms.
Other Causes of Hypothyroid
Other potential causes include surgery, radiation, or certain medications. Lack of iodine in the diet can also cause hypothyroidism, although it’s rare. Strong family history or other autoimmune conditions could increase your chances. And sometimes, the cause isn’t known.
It’s actually quite common to either develop or discover hypothyroidism with pregnancy as you need extra thyroid hormone for the growing fetus.
What are Hypothyroid Symptoms?
The thyroid acts like the master of metabolism and affects nearly all the organs in your body, which can make symptoms of hypothyroidism hard to pinpoint.
Symptoms of hypothyroidism in women include:
- Irregular menstrual cycles
- Feeling cold all the time
- Weight gain
- Dry skin
- Hair loss
- Brittle nails
- Brain fog and memory issues
In this article I talk about the 7 common thyroid symptoms that often get missed. If you’re suspecting hypothyroidism, it is worth a read.
Lab Tests for Hypothyroidism
I recommend the following labs for a comprehensive look at your thyroid health:
- Total and Free T4
- Total and Free T3
- Reverse T3
- Anti-Thyroid peroxidase (Anti-TPO)
- Anti-thyroglobulin (TgAb)
These labs help to paint a picture of what’s happening with your thyroid hormone levels and hopefully catch hypothyroid in its early stages.
In my clinical practice, we test these labs in patients prior to getting pregnant and then retest in early pregnancy, like as soon as someone knows they’re pregnant so we can make necessary adjustments. More on that soon.
@drjolenebrighten Test. Don’t Guess! #thyroidproblem #thyroidhealth #drjolenebrighten #learnontiktok ♬ Holy – Justin Bieber
What are Your Chances of Getting Pregnant with Hypothyroidism?
Since it’s a common reason for infertility, it’s natural to worry about your chances of getting pregnant with hypothyroidism. But it’s absolutely possible (and I speak from experience) when treated appropriately.
Does Hypothyroidism Affect Fertility?
There are several ways hypothyroidism can impact your chances of getting pregnant—anovulatory cycles, luteal phase defects, hyperprolactinemia, and sex hormone imbalances.
An anovulatory cycle is a menstrual cycle without ovulation. Hypothyroid disrupts the menstrual cycle because it can interrupt the regular egg release that happens during ovulation. In fact, thyroid hormone is essential for follicle development—making sure the egg is mature enough to be ovulated.
Lack of ovulation impacts fertility because you need to regularly ovulate—or release an egg to be fertilized and implanted—to become pregnant. No ovulation means no egg release. Even if you occasionally ovulate, it can still make it challenging to become pregnant because it’s hard to pinpoint when you’re fertile.
Here’s the good news: if you know you have hypothyroidism and are trying to conceive, you can take steps to increase your chances of getting pregnant. You can significantly improve your odds of becoming pregnant with the proper treatment and lifestyle support.
Luteal Phase Defects
The luteal phase is the second half of your menstrual cycle, starting after ovulation and ending the day before your period starts. A luteal phase defect is when the luteal phase is too short—usually due to low progesterone levels. Low thyroid levels are linked to luteal phase defects making it difficult to become pregnant.
Prolactin is a hormone that’s released during breastfeeding. It also plays a role in fertility by helping to mature the egg and keeping the uterine lining healthy. When prolactin levels are too high, it can interfere with ovulation.
Hypothyroid can increase the production of a hormone called thyrotropin releasing hormone (TRH). TRH tells the body to release more TSH and prolactin, which can lead to hyperprolactinemia.
Sex Hormone Imbalances
Since thyroid is intimately linked to sex hormones, an imbalance in one can cause an imbalance in the other. For example, sex hormone binding globulin (SHBG), a hormone that carries testosterone and estrogen in the blood, is made in the liver and thyroid helps regulate SHBG. When SHBG is out of balance, levels of bioavailable hormones are thrown off, impacting fertility.
@drjolenebrighten What do they do? #thyroid #thyroidproblems #drjolenebrighten #hypothyroidism #health #healthy #healthylifestyle ♬ Get Low – Dillon Francis & DJ Snake
Hypothyroidism and Pregnancy: Here’s What to Know
While it’s possible to get pregnant with hypothyroidism, there are some risks. I want to emphasize that much of this is based on undiagnosed or untreated hypothyroidism. If you’re under the care of your OB/GYN and you have hypothyroidism, they should be monitoring you closely during pregnancy to keep you safe and healthy.
But it’s also essential to look at why it is so important to get treated for hypothyroidism before becoming pregnant. The American College of Obstetricians and Gynecologists (ACOG) and the Endocrine Society recommend anyone who is pregnant or considering pregnancy be screened for thyroid conditions to make sure that thyroid hormones are within healthy ranges.
Hypothyroidism in Pregnancy Effects on Mother
As you saw earlier, hypothyroidism can increase the chance of miscarriage for pregnant mamas. But the complications of severe untreated hypothyroid for the mother could also include:
- Pre-eclampsia or high blood pressure
- Postpartum hemorrhage
- Muscle pain and weakness
- Congestive heart failure
- Placental abruption
Hypothyroidism in Pregnancy Effects on Baby
A baby starts to make thyroid hormone on its own about halfway through a pregnancy, but until then, it relies on the mother. If mama has low thyroid hormone, the baby also has a risk of being born with low thyroid hormone levels.
Hypothyroidism in pregnancy effects on baby include:
- Premature birth
- Low birth weight
- Cognitive issues due to poor brain development
- Neurological abnormalities
- Breathing problems
Once again, this is for severe undiagnosed or untreated hypothyroid.
Labs to Monitor Thyroid During Pregnancy
It is important to have regular lab testing during pregnancy, which includes monitoring your thyroid. A TSH, free T4, and free T3, along with thyroid antibodies should be ordered prior to conception and then continued to be monitored based on those findings. The Endocrine Society recommends running these tests before pregnancy and that TSH should be below 2.5 mIU/L during first trimester screening.
Hypothyroidism is associated with an increased risk of miscarriage and untreated hypothyroidism can cause issues with embryo development.
If you have a history of Hashimoto’s, meeting with a maternal fetal medicine specialist (MFM) is important as this can create additional complications in your pregnancy. Since TPO antibodies can cross the placenta, a third trimester ultrasound may be recommended in order to visualize the baby’s thyroid.
Thyroid Medication During Pregnancy
Thyroid medication may be necessary to have a healthy pregnancy. If you’re already on thyroid medication, you’ll want to talk to your doctor about monitoring your thyroid and making medication adjustments as needed based on your lab results.
Because T4 is the hormone that crosses the placenta and what baby depends on in early pregnancy, it is important to ensure you have enough T4 available. This is why your doctor may recommend Levothyroxine (synthetic T4) if your TSH and/or free T4 is not optimal.
While I’ve had many patients come to me wanting to start Armour or a natural desiccated thyroid (NDT) hormone, pregnancy is not the time to start a T4/T3 combination medication. The research we have is based on giving T4, which again, is what we know the baby absolutely needs. We also do not want to be adjusting T3 up and down during pregnancy because this can create complications like anxiety, racing heart, heat intolerance, and may be problematic in pregnancy.
If you are already taking an NDT and then find yourself pregnant, your provider will likely choose to keep you on this medication since pregnancy can be a tricky time to switch medications, especially if you have a history of not tolerating other medications. They may add synthetic T4 in addition to your medication should your TSH be elevated or free T4 be lower than 1 ng/dL.
The main take home is that it is important to monitor, leverage medication as needed to maintain the baby’s health and your own, and retest with any medication adjustments.
Since postpartum is a common time to see both hypothyroidism and Hashimoto’s arise, this is called postpartum thyroiditis, it is important to continue to monitor thyroid symptoms and labs during this time.
@drjolenebrighten Thyroid support can look like nutrient dense foods, lowering stress, & quality sleep. See the playlist below for more info #thyroidsupport #hashimotos #hashimotosthyroiditis #thyroidproblems #thyroidhealth #hormonedoc #hormonedoctor #hormonehealth ♬ BILLIE EILISH. – Armani White
Hypothyroidism Natural Treatments
I’m always a fan of using natural treatments to support the body. While medication is often necessary, natural therapies can help manage symptoms and support healthy thyroid hormone levels.
I want to caution that you don’t want to change any part of your treatment plan for hypothyroid without discussing it with your healthcare provider. Never stop taking your medications, especially during pregnancy. Natural options are meant to provide a solid foundation to help support the body. Still, sometimes medications are necessary, and that’s okay. You can use many of these therapies alongside your medication, just be sure to check in with your prescribing physician.
Eat a Diet Full of Optimal Nutrients for Thyroid Health
A number of nutrients are critical for optimal thyroid function, so a diet rich in these nutrients is essential for anyone with hypothyroidism.
Some of the most crucial nutrients for thyroid function include:
- Iodine. Iodine is one of the most important nutrients for thyroid function. It’s used by the thyroid to make thyroid hormone. Some people with hypothyroidism that live in developed nations are deficient in iodine. Iodine deficiency is much more common in developing nations. You can get iodine from eating seafood, seaweed, and iodized salt. During pregnancy and breastfeeding, iodine needs increase.
At the same time, too much could also be a problem, especially if you are deficient in selenium. It’s important not to supplement without the guidance of a healthcare provider and to make sure your iodine intake is balanced with selenium. This is why we include 200 mcg of selenium in our Prenatal Plus alongside iodine to ensure the right balance of these minerals.
- Selenium. Selenium is a micronutrient needed to convert inactive thyroid hormone into an active form. Low levels of selenium can mean you make less active thyroid hormone. Since selenium is also an antioxidant, it can help protect the thyroid cells from oxidative damage.
You can find selenium in organ meat, seafood, and brazil nuts (although the amount can vary based on the soil content).
- Zinc. Zinc is critical for many different aspects of thyroid function, including hormone production and converting T4 to T3. You can find zinc in oysters, red meat, poultry, and legumes.
- Omega-3 fatty acids. These healthy fats are anti-inflammatory, so they can help cool down inflammation in the body, which is vital when you’re dealing with autoimmunity like Hashimoto’s. You can find omega-three fatty acids in fatty fish like wild salmon or sardines, and in plants like chia seeds (but many choose to supplement if they don’t eat enough fish).
- Magnesium. Magnesium is a favorite for thyroid health, and studies link low magnesium and Hashimoto’s risk. People with adequate magnesium are less likely to be diagnosed with hypothyroidism.
Plus, it’s great for mood, relaxation, and even keeping bowels regular (all important during pregnancy too). Magnesium is found in many foods, including dark chocolate, pumpkin seeds, and leafy greens
For a deep dive into the best foods for your thyroid, check out my article here.
Take Your Prenatal Vitamins
A prenatal vitamin can help fill nutritional gaps to ensure you get the nutrients you and your baby need. It’s important to continue taking your prenatal even if you don’t think you need it and to start before you become pregnant. You can read more about when to take a prenatal vitamin here.
Nutrient needs go sky high with pregnancy, and sometimes the most nourishing foods are suddenly less than appetizing when you’re pregnant. So it’s hard to get all the nutrients you need from food alone.
But not all prenatal supplements are created equal, which is why I created Prenatal Plus. Also, another important hint: take your prenatal away from your thyroid meds, as nutrients like iron and calcium could impair absorption of your medication.
There are many supplements I use to support thyroid health, but not all are safe for pregnancy, so if you have any questions, be sure to ask your healthcare provider.
I created the Thyroid Support supplement with essential thyroid nutrients to provide comprehensive thyroid support.
This is a big one. It’s no secret that stress can wreak havoc on our bodies, but managing stress levels is crucial when you have hypothyroidism.
Chronic stress can disrupt the normal functioning of your hypothalamic-pituitary-adrenal (HPA) axis, which can lead to increased levels of stress hormones (e.g. cortisol) and inflammation and can further suppress thyroid function. The HPA axis is the system in which your brain and adrenal glands communicate. In cases of inflammation, autoimmune disease, or prolonged stress, this system can become out of balance. The imbalance is known as dysregulation and can contribute to a whole range of symptoms, including worsening thyroid function. This is also why it can be confusing to understand if your symptoms are due to adrenal and thyroid function.
The events, places, or situations that cause stress in your life can sometimes be beyond your control, but there are steps you can take to help manage them. Exercise, meditation, and relaxation techniques can all help manage stress.
Focus on Gut health
As I mentioned above, there’s a close relationship between gut health and thyroid, especially Hashimoto’s. Intestinal permeability (often called leaky gut) and inflammation are thought to play a role in the development of autoimmunity. Plus, gut imbalances can also exacerbate the stress response, furthering any HPA axis dysregulation.
It takes time to heal your gut, but you can start supporting it with probiotics, fermented foods, and fiber. If you deal with food sensitivities or digestive issues, you may want to work with a practitioner before getting pregnant to get things under control.
Eat for Blood Sugar Balance
Interestingly, there’s a link between impaired blood sugar and hypothyroid. People with hypothyroidism are more likely to develop type 2 diabetes and vice versa. Your thyroid is critical for keeping your blood sugar in an optimal range.
Blood sugar balance during pregnancy is especially important for mother and baby, so now is the time to work on stable levels. This means regularly eating throughout the day, including protein and fat at every meal, to help slow down the release of sugar into the bloodstream. It also means avoiding refined carbohydrates and sugary foods as much as possible.
You may need to experiment a bit to find what works for you, but generally, a diet that focuses on whole, unprocessed, fiber-rich foods is a great start.
Final Thoughts on Pregnancy and Hypothyroid
In summary, if you have hypothyroidism and are trying to conceive or are already pregnant, there are some essential things to consider.
First, it’s important to work with a healthcare provider who understands thyroid health, especially managing it in pregnancy. You’ll likely need to adjust your medication dose as your pregnancy progresses. You may also need additional support in supplements or diet changes.
Secondly, focus on lifestyle factors that can help support thyroid function and manage stress levels. This includes eating a healthy diet, exercising regularly, and managing stress.
Taking these steps to support your thyroid and overall health puts you in the right position to become pregnant and have a healthy, happy pregnancy.
Share this article:
- Garber JR, Cobin RH, Gharib H, et al.. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association [published correction appears in Endocr Pract.. Endocr Pract.. 2012. 18(6). 988-1028.
- U.S. Department of Health and Human Services.. Hypothyroidism (underactive thyroid). National Institute of Diabetes and Digestive and Kidney Diseases..
- ACOG. Thyroid Disease in Pregnancy: ACOG Practice Bulletin,. Obstetrics & Gynecology. 2020. 135. e261-e274.
- Ajmani NS, Sarbhai V, Yadav N, Paul M, Ahmad A, Ajmani AK. . Role of Thyroid Dysfunction in Patients with Menstrual Disorders in Tertiary Care Center of Walled City of Delhi. J Obstet Gynaecol India. 2016. 66(2). 115-119.
- Verma I, Sood R, Juneja S, Kaur S. Prevalence of hypothyroidism in infertile women and evaluation of response of treatment for hypothyroidism on infertility.. Int J Appl Basic Med Res. 2012. 2(1). 17-19.
- De Groot L, Abalovich M, Alexander EK, Amino N, Barbour L, Cobin RH, Eastman CJ, Lazarus JH, Luton D, Mandel SJ, Mestman J, Rovet J, Sullivan S.. Management of Thyroid Dysfunction during Pregnancy and Postpartum: An Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology & Metabolism. 2012. 97. 2543-2565.
- Brent GA. Environmental exposures and autoimmune thyroid disease. Thyroid. 2010. 20(7). 755-761.
- Knezevic J, Starchl C, Tmava Berisha A, Amrein K. . Thyroid-Gut-Axis: How Does the Microbiota Influence Thyroid Function?. Nutrients. 2020. 12(6). 1769.
- Sahay RK, Nagesh VS. Hypothyroidism in pregnancy.. Indian J Endocrinol Metab. 2012. 16(3). 364-370.
- Alemu A, Terefe B, Abebe M, Biadgo B.. Thyroid hormone dysfunction during pregnancy: A review. Int J Reprod Biomed. 2016. 14(11). 677-686.
- Triggiani V, Tafaro E, Giagulli VA, et al. Role of iodine, selenium and other micronutrients in thyroid function and disorders.. Endocr Metab Immune Disord Drug Targets. 2009. 9(3). 277-294.
- Severo JS, Morais JBS, de Freitas TEC, et al.. The Role of Zinc in Thyroid Hormones Metabolism.. Int J Vitam Nutr Res.. 2019. 89(1-2). 80-88.
- Wang K, Wei H, Zhang W, et al.. Severely low serum magnesium is associated with increased risks of positive anti-thyroglobulin antibody and hypothyroidism: A cross-sectional study. . Sci Rep.. 2018. 8(1). 9904.
- Bartalena L, Brogioni S, Grasso L, Velluzzi F, Martino E.. Relationship of the increased serum interleukin-6 concentration to changes of thyroid function in nonthyroidal illness.. J Endocrinol Invest.. 1994. 17(4). 269-274.
- Mizokami T, Wu Li A, El-Kaissi S, Wall JR. Stress and thyroid autoimmunity.. Thyroid.. 2004. 14(12). 1047-1055.
- Sudo N, Chida Y, Aiba Y, et al.. Postnatal microbial colonization programs the hypothalamic-pituitary-adrenal system for stress response in mice.. J Physiol.. 2004. 558(Pt 1). 263-275.
- Kadiyala R, Peter R, Okosieme OE. Thyroid dysfunction in patients with diabetes: clinical implications and screening strategies. Int J Clin Pract.. 2010. 64(8). 1130-1139.
- Niu YF, Shao Y, Zhao XH, Wen HX, Tao YD. [RP-hPLC determination of flavonoids in several flowers]. Zhongguo Zhong Yao Za Zhi. 2008. 33(18). 2102-2104.
- Garduño-Garcia Jde J, Alvirde-Garcia U, López-Carrasco G, et al.. TSH and free thyroxine concentrations are associated with differing metabolic markers in euthyroid subjects. Eur J Endocrinol.. 2010. 163(2). 273-278.
- Verma I, Sood R, Juneja S, Kaur S.. Prevalence of hypothyroidism in infertile women and evaluation of response of treatment for hypothyroidism on infertility. Int J Appl Basic Med Res. 2012. 2(1). 17-19.
- Selva DM, Hammond GL.. Thyroid hormones act indirectly to increase sex hormone-binding globulin production by liver via hepatocyte nuclear factor-4alpha.. J Mol Endocrinol.. 2009. 43(1). 19-27.
About The Author
Can a Woman With Thyroid Problems Get Pregnant?
- First things first: Can you get pregnant with a thyroid condition?
- What’s important to do and know before trying to get pregnant?
- What’s important to do and know during pregnancy?
- What’s important to do and know after giving birth?
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
Are you currently being treated for a thyroid condition or you have thyroid nodules or a goiter? Have you had a thyroid condition in the past? Do you have an autoimmune disorder or a family history of thyroid autoimmune disease, like Graves’ disease or Hashimoto’s disease? What if you’ve had high-dose neck radiation or treatment for hyperthyroidism?
If you answered “yes” to any of these questions and are starting to think about having kids (or even if you’re just curious), read on.
The thyroid gland plays a very important role in your reproductive health, and you may have many questions about your fertility and your current medications. The butterfly-shaped gland does, after all, lead to issues for 1 in 8 people with ovaries. Ultimately, your best chance at conceiving and having a healthy pregnancy is when your condition is properly managed and treated.
Absolutely — but hyperthyroidism (an overactive thyroid gland) and hypothyroidism (an underactive thyroid gland) can have a negative effect on fertility and make conception more challenging. That’s because both conditions have been linked to irregular menstrual cycles. When cycles are irregular, timing sex or insemination around the days you’re most likely to get pregnant can be difficult.
If you already know you have a pre-existing thyroid condition, you have a major advantage over the many people who are undiagnosed: Treating your thyroid condition before trying to conceive can help you reduce the likelihood of fertility issues. In one study of a group of almost 400 women dealing with infertility, 24% of participants were found to have hypothyroidism — but within a year of treatment, 76% were able to conceive.
Below, we’re providing an overview of what to keep in mind before, during, and after pregnancy if you have a pre-existing thyroid condition.
While, like we mentioned above, getting pregnant is definitely possible if you have a thyroid condition, there are a few things to understand before you start trying to conceive.
“Thyroid hormones are important for your general health, but we also know that pregnancy can be impacted by thyroid problems if those problems aren’t addressed first,” explained Dr. Nataki Douglas, MD, PhD, a reproductive endocrinologist and the chair of the Modern Fertility Medical Advisory Board, in a virtual Q&A on trying to get pregnant.
In most cases, thyroid disorders are diagnosed by your primary care provider or an endocrinologist — a specialist who treats hormone problems like thyroid disease. Chances are you’re already under the care of one of these doctors, so let them know you’re in the process of planning for kids and they can help you manage your thyroid disorder before conception to avoid fertility-related issues down the line.
If you’ve had thyroid cancer and received radioactive iodine (RAI) doses to ensure the stability of your thyroid function and confirm remission of thyroid cancer, the Endocrine Society recommends avoiding pregnancy for six months to one year.
Thyroid-stimulating hormone (TSH), the hormone made in the pituitary gland, tells your thyroid how much T4 and T3 to make. By this time, you may already be accustomed to having regular blood tests to test your thyroid levels and know the following info:
- A high TSH level usually indicates hypothyroidism: Your thyroid gland is underactive and not responding to the signal from the pituitary gland to make thyroid hormones, so the TSH is extra high, while the thyroid hormones are low.
- A low TSH level usually indicates hyperthyroidism: Your thyroid gland is overactive and the extra thyroid hormone is inhibiting production of thyroid stimulating hormone. The TSH is low while the thyroid levels are typically high.
The Endocrine Society recommends “all women considering pregnancy with known thyroid dysfunction should be tested for abnormal TSH concentrations before pregnancy” and that TSH should be below 2.5 mIU/mL during the first trimester. “Normal” TSH values can range depending on the lab used, but they’re typically between 0.4 and 4.5 mIU/L. However, a study of nonpregnant women taking thyroid medications showed over 40% were not even in the normal range and were either hypo- or hyperthyroid — baring the case to check your TSH levels regularly even when on medication.
Many people worry about the effects of medication on their developing fetus, but the benefits of taking the thyroid medicines your doctor prescribes greatly outweigh the risks to both the birthing parent and the fetus. “Being compliant with thyroid disorder treatment and monitoring is an essential component to fertility and important for a successful pregnancy,” says Dr. Nadiyah Chaudhary, PharmD, BCPS, a pharmacist who works closely with the reproductive endocrinologist care teams at the University of Chicago Medicine to assist in medication management.
If hyperthyroidism is left untreated with medicine during pregnancy, that can lead to:
- Increased risk of premature birth
- Increased risk of preeclampsia
- Increased risk of thyroid storm (sudden, severe worsening of symptoms)
- Increased risk of a fast heart rate in the newborn
- Increased risk of low birth weight
- Increased risk of miscarriage
If hypothyroidism is left untreated with medicine during pregnancy, that can lead to:
- Increased risk of anemia
- Increased risk of preeclampsia
- Increased risk of low birth weight
- Increased risk of miscarriage
- Increased risk of stillbirth
- Problems with fetal growth and brain development
With any pregnancy comes a rise in hormones, but two of them — human chorionic gonadotropin (hCG) and estrogen — can trigger a temporary rise in thyroid hormone levels in your blood.
Thyroid hormone levels naturally change throughout pregnancy due to normal physiological changes. For this reason, Dr. Chaudhary explains, “There are trimester-specific ranges used to interpret lab values of thyroid function tests.” In the first trimester, for example, the normal TSH range is less than 2.5 mIU/L as levels between 2.5 and 5.0 are associated with increased pregnancy loss.
Here’s how thyroid hormones may change during pregnancy:
- High levels of hCG in the first trimester could result in slightly low TSH before going back to normal later on in the pregnancy.
- Estrogen may increase the total thyroid hormone levels — but the thyroid gland may still be functioning normally as long as TSH and fT4 levels are within range for that specific trimester.
Aside from thyroid hormone levels, the thyroid gland may also become larger during pregnancy — but this happens more frequently in iodine-deficient areas than it does in the US.
Iodine is a key nutrient for thyroid hormones and thyroid health. * During pregnancy and lactation (whether or not you’re breastfeeding/chestfeeding), iodine requirements from the US Food and Drug Administration increase from 150 for nonpregnant people micrograms (mcg) to 290 mcg.
That said, supplemental iodine — which is a common component of prenatal vitamins — may not be recommended if you’re taking levothyroxine (LT4), also known as L-thyroxine, a manufactured form of the thyroid hormone thyroxine (T4). Since prenatal vitamins are an essential part of preconception and pregnancy nutrition, it’s important to talk to your healthcare provider about whether or not a prenatal vitamin with iodine is right for you.
Here’s what you can expect once you’re actually pregnant and have a thyroid condition.
Once someone with a pre-existing thyroid condition becomes pregnant, the Endocrine Society has guidelines for doctors to follow when it comes to adjustments in thyroid medication during pregnancy:
- If you had hyperthyroidism (overactive thyroid) before getting pregnant, your healthcare provider may prescribe antithyroid medicines called propylthiouracil in the first trimester and change to medications called methimazole in the second and third trimesters. The timing of these medications is important to reduce the risk of liver problems and birth defects.
- If you had hypothyroidism (underactive thyroid) before getting pregnant, you may need to increase your medication dosage and/or change to a new medication. Levothyroxine is the most common medicine used to treat hypothyroidism during pregnancy. It’s safe to take this medicine during pregnancy.
If all of these changes seem a little overwhelming, specialists like Dr. Chaudhary are here to support you by helping you do the following things:
- Obtain insurance approval for your new medications.
- Enroll in financial assistance programs.
- Coordinate delivery of your medications.
- Get counsel on your new medication regimen.
The general population of pregnant people doesn’t receive screening for thyroid dysfunction. However, for those with a personal history of thyroid disorders, the American College of Obstetricians and Gynecology (ACOG), the Society for Maternal-Fetal Medicine (SMFM), and the Endocrine Society clinical practice guidelines recommend screening.
Because providers may differ in their screening practices, it’s important to be your own advocate on this from the very beginning. Always share your thyroid health history at your very first prenatal appointment. Experts say testing for serum TSH abnormalities should be done by your ninth week of pregnancy or at the time of your first visit.
After your delivery, keep tabs on these aspects of both your own and your newborn’s health.
Most people with hypothyroidism, for example, need to decrease the levothyroxine (Synthroid) dosage they received during pregnancy to the pre-pregnancy dose after delivery.
Both antithyroid and thyroid replacement medicines (like Synthroid) are safe to take at low doses while you’re breastfeeding/chestfeeding.
This is because the thyroid receptor antibodies that cross the placenta during pregnancy can affect the fetus. The recommendation is to test the birthing parents’ antibody levels at 22 weeks gestation if you have current or past Graves’ disease. After delivery, testing the infant for thyroid disease (and treating them if necessary) is recommended.
Some thyroid complications can occur postpartum. People with a history of thyroid problems are at an increased risk of postpartum thyroiditis, a condition that occurs in about 5%-10% of people with ovaries when the thyroid becomes inflamed after having a baby. It may first cause the thyroid to be overactive, but it can eventually lead to an underactive thyroid.
However you’re measuring TSH levels, it’s always important to talk to your healthcare provider about how to best monitor your thyroid health as you go after your fertility goals, move through your pregnancy, and navigate new parenthood.
This article was reviewed by Dr. Jennifer Conti, MD, MS, MSc.
* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Dr. Jenn Conti is an OB-GYN and serves as an adjunct clinical assistant professor at Stanford University School of Medicine.
Pregnancy and hypothyroidism. What to do?
Subject to adequate treatment, observation by an endocrinologist before pregnancy, during and during feeding.
Hypothyroidism is an insufficiency of thyroid hormones. It is most often caused by a disease called autoimmune thyroiditis.
When planning, women with hypothyroidism should definitely take a blood test for TSH and visit an endocrinologist with the result.
Your endocrinologist will adjust your dose of levothyroxine (Eutyrox, L-thyroxine) you are taking.
For women who are planning a pregnancy, the normal TSH value is up to 2.5 µm / ml, and not the figure indicated on the laboratory form as the upper limit of the norm. Why are the rules more stringent?
In the first half of pregnancy, the fetal thyroid gland is still developing and does not work. The baby receives these hormones from the mother. The normal level of thyroid hormones is necessary for the proper development of the nervous system of the fetus, it affects the future intelligence of the child. Therefore, it is so important that in the first trimester of pregnancy (when a woman may not yet know about her pregnancy), the mother’s hormones are sufficient to provide for the fetus.
IMPORTANT! It is also necessary to choose the right dose of levothyroxine in order for pregnancy to occur at all. The lack of thyroid hormones in a woman’s body impairs her ability to conceive.
When you find out that you are pregnant, you need to take a blood test for TSH and free T4.
In the first trimester of pregnancy, the need for levothyroxine increases in all pregnant women by about 30-50%. The doctor will determine the dose of the drug that is most suitable for you, the frequency of control blood tests and examinations.
If the test results are good, hormones (TSH and fT4) should be monitored once a trimester. If your tests are not normal, then after changing the dose of the drug, it is necessary to repeat the tests after 1.5 months.
TSH values below 2. 5 in the first trimester and below 3.0 µm/ml in the second and third are considered normal during pregnancy.
All pregnant women, regardless of thyroid disease, should receive 250 micrograms of iodine daily throughout pregnancy and lactation .
Iodine is part of the thyroid hormones.
During pregnancy, the need for hormones increases, and, accordingly, for iodine. Most multivitamins for pregnant women include this trace element, but in varying amounts. If you have been prescribed multivitamins that do not contain iodine, or you do not take any multivitamins, , then you should take additional iodine preparations (Jodomarin, Yodbalance, Yod-Active) at a dose of 250 mcg. An increased need for iodine persists during lactation, so it is advisable to take iodine preparations until the end of lactation.
Immediately after childbirth, the dose of levothyroxine will need to be reduced to the same dose you took before pregnancy.
3 months after delivery, take a blood test for TSH to make sure the dose is correct and visit a doctor.
If you have hypothyroidism and take levothyroxine on a regular basis, breastfeeding is not contraindicated for you! This drug in its structure is exactly the same as its own hormone thyroxine, it does not have a harmful effect on the child.
Have an easy pregnancy!
Pregnancy due to hypothyroidism – effects on conception and treatment
Dysfunction of the thyroid gland is one of the causes of infertility, miscarriage and fetal malformations.
In order to avoid dangerous complications, it is very important to diagnose the pathology in a timely manner and undergo a course of treatment. You can make an appointment with a doctor by calling the phone number listed on the website, or by using the appointment button.
Hypothyroidism is a condition caused by insufficient thyroid function over a long period of time, which develops mainly in women over the age of 35 years.
Symptoms of hypothyroidism during pregnancy
You can suspect the presence of hypothyroidism by paying attention to the symptoms, which include:
- general weakness,
- increased fatigue,
- relative weight gain against the background of reduced appetite,
- dyspeptic symptoms,
- deterioration of hair, dry skin,
- hypertension or hypotension, bradycardia,
- menstrual disorders,
- apathy, lethargy,
As we can see, in themselves, signs of a decrease in the production of thyroid hormones are not specific. Moreover, often patients focus the doctor’s attention on disorders associated with any one system of the body.
Diagnosis of hypothyroidism
Diagnosis of hypothyroidism involves blood tests to determine:
- serum levels and free fractions of the hormones T3 and T4;
- serum level of the hormone TSH;
- antibodies to thyroperoxidase and thyroglobulin.
If there is primary hypothyroidism, which is caused by damage to the thyroid gland, then the analyzes show an increase in the concentration of thyroid-stimulating hormone against the background of normal (with subclinical form) or reduced (with manifestation) thyroid hormone levels.
In secondary hypothyroidism, which develops as a result of the pathology of the hypothalamic-pituitary region, a decrease in TSH, T3 and T4 is detected.
Analysis of antibodies to TPO allows you to diagnose autoimmune thyroiditis. In this case, the enzyme (thyroid peroxidase) is perceived as foreign, and therefore specific antibodies are formed in the body.
Additionally, an ultrasound of the thyroid gland is prescribed, which allows you to study in detail the structure of the organ. It should be borne in mind that in the early stages of the disease, any changes may be absent.
In addition, the doctor may prescribe an additional magnetic resonance imaging of the pituitary gland.
Infertility due to hypothyroidism
Inadequate production of thyroid hormones provokes disturbances in the synthesis and metabolism of sex hormones that are involved in the regulation of the menstrual cycle, which causes the absence of ovulation. In the body, the least active forms of estrogens begin to be excessively produced, the production of gonadotropic hormones (follicle-stimulating and luteinizing) is disrupted.
Thyroid hormones are involved in the production of a special protein that binds some sex hormones. Accordingly, with a decrease in the production of thyroid hormones, protein production decreases, which provokes an increase in the level of the male hormone testosterone.
With a long-term deficiency of thyroid hormones, hyperprolactinemia develops (a condition caused by an increased level of prolactin), which is one of the causes of female infertility.
As we wrote above, in patients with hypothyroidism, certain menstrual irregularities are detected. In most cases, this is a hypomenstrual syndrome characterized by hypomenorrhea (a decrease in the volume of menstrual flow) and oligomenorrhea (an increase in the duration of the menstrual cycle up to 40 or more days). In some cases, there is amenorrhea (complete cessation of menstruation). Lack of ovulation in the menstrual cycle and dysfunctional uterine bleeding are also characteristic of hypothyroidism.
According to statistics, infertility due to the absence of ovulation is usually diagnosed in patients with a manifest (having clinical manifestations) form, while in a subclinical (asymptomatic) form of hypothyroidism, conception is possible. However, in this case, there is a high probability of developing complications already in the gestation period (miscarriages, developmental anomalies), and therefore this condition should be diagnosed at the stage of pregnancy planning. Most often, a lack of thyroid hormones provokes pathologies of the nervous system, skeleton, tissues of the kidneys and lungs in the fetus.