Can a Woman With Thyroid Problems Get Pregnant?

Medically reviewed on July 18, 2023 by Amy Harris, MS, RN, CNM. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

• Thyroid and Pregnancy 101
• Thyroid Diseases and Pregnancy FAQs
• Seeking Treatment for Thyroid Issues Before Getting Pregnant
• Taking Steps to Understand Your Thyroid
• Related Content

Whether you’ve already been diagnosed with thyroid issues or only suspect that your symptoms are related to a thyroid condition, existing health challenges are sometimes magnified while trying to conceive.

So, can a woman with thyroid problems get pregnant? Yes—but women working through thyroid challenges can encounter unexpected hurdles on their fertility journeys. [1] Thyroid dysfunction could also be the underlying condition behind fertility problems you may experience.

In this article, we’ll explore numerous topics related to pregnancy and thyroid issues. We’ll discuss how thyroid function impacts menstruation, fertility, and pregnancy — as well as how hypothyroidism and hyperthyroidism can impact soon-to-be parents. We’ll also answer some frequently asked questions about thyroid issues and fertility to help you navigate the conception process while managing a thyroid condition.

Thyroid and Pregnancy 101

Your thyroid gland is a small organ located in your throat that produces a wide variety of hormones—chemical messengers directing essential body functions such as how your body uses energy (your metabolism). [2,3] Diseases of the thyroid cause it to make either too much (hyperthyroidism) or too little of thyroid hormone (hypothyroidism)Let’s explore how thyroid issues can impact your reproductive health.

Your Thyroid and Menstruation

Thyroid issues in women, including those assigned female at birth (AFAB), are more common than in cisgender men: One in eight women will experience thyroid dysfunction in their lifetime. [3] Since your thyroid produces a wide variety of hormones, you might experience menstruation changes or issues if you’re struggling with thyroid disease.

There are a few important things to note about thyroid issues and menstruation [3]:

• Flow – Thyroid hormone production can impact menstrual bleeding. Too much thyroid hormone can ramp up your body’s processes, producing heavier periods, while lower-than-average thyroid function can lead to lighter periods
• Frequency – Changes in your thyroid hormone production can also impact the frequency and regularity of your periods. Some thyroid diseases can be precursors to a condition called amenorrhea—a phenomenon that can stop your period for multiple months (called amenorrhea). [3]
• Premature Menopause – Women with autoimmune thyroid conditions(like Graves’ disease) may go through menopause early (before the age of 40). [3]

Thyroid and Fertility

Since thyroid function and the menstrual cycle are closely linked, the latter can also impact your ability to get pregnant. [3] Why? Because changes to your menstrual cycle (and your ovary function) can impact ovulation.

Ovulation occurs when an egg is released from the ovaries and moves into the fallopian tubes, where sperm can fertilize it—a critical step in the fertility process.5 After ovulation, most people experience one of three outcomes:

1. Pregnancy – A fertilized egg implants in the uterine lining and pregnancy begins.
2. Unfertilized menstruation – If an egg isn’t fertilized in the fallopian tube, it will move to the uterus and eventually be released (along with the uterine lining) during menstruation.
3. Fertilized menstruation – Even if they’re fertilized, not all eggs are viable—non-viable, fertilized eggs often don’t implant into the uterine lining, and they’re shed (along with the uterine lining) during menstruation.

What's the link between thyroid and fertility problems? Since thyroid hormone production can impact both ovarian function and menstrual cycles. By changing the timing of ovulation and available egg’s ability to implant, thyroid disorders can delay the time it takes for someone to conceive. [3]

Thyroid and Pregnancy

Some pregnant people don’t experience symptoms of a thyroid problem until they are pregnant..1 There are two explanations for why this happens. First, pregnancy puts increased stress on your thyroid. Two hormones higher in pregnancy (human chorionic gonadotropin or HCG and estrogen, impact thyroid function, potentially taxing your underactive or overactive thyroid gland for the first time. [6]

Second, diagnosing thyroid conditions during pregnancy can be difficult because many of the symptoms of the two most common thyroid disorders (hypothyroidism and hyperthyroidism) are also possible pregnancy-related symptoms. [3]

Hyperthyroidism

People with hyperthyroidism have an overactive thyroid—they produce more thyroid hormones than needed.1 Hyperthyroidism appears in every 1 to 4 pregnancies in the USA. [8] Graves’ disease, an autoimmune condition caused by a combination of environmental triggers and genetic factors, is the most common cause of hyperthyroidism in women of childbearing age. [7] Very high levels of the pregnancy hormone hCG, seen in severe forms of morning sickness (hyperemesis gravidarum), may cause transient hyperthyroidism in early pregnancy. [7] The most common symptoms of an overactive thyroid, or hyperthyroidism, (regardless of pregnancy status) include [9]:

• Unexplained weight loss
• Shakiness or trembling (particularly in the hands)
• An irregular or fast heartbeat

Pregnant people with hyperthyroidism may have trouble gaining enough weight during pregnancy. Often this lag in pregnancy weight gain can clue healthcare providers into a possible thyroid disorder. [8]

Here’s a snapshot of average weight gain during pregnancy (for single-child births) based on your general weight status before getting pregnant [5]:

• Underweight people gain anywhere from 28 to 40 pounds during pregnancy
• People of average weight gain 25 to 35 pounds
• Overweight people gain 15 to 25 pounds
• People with a very high body weight gain 11 to 20 pounds

If any of these symptoms sound familiar, or you know you have a family history of hyperthyroidism or Graves’ disease, make sure to talk to your provider. Hyperthyroidism can lead to miscarriage, low birth weight, preeclampsia (a life-threatening condition for mothers), stillbirths, birth defects, and premature birth. [1,7] Fortunately, when healthcare providers can prepare for treating hyperthyroidism or Graves’ during pregnancy, monitoring of the pregnancy, fetus, and even treatment can reduce these risks. [7,9]

Hypothyroidism

People with hypothyroidism (both before and during pregnancy) have an underactive thyroid gland, meaning they don’t produce enough thyroid hormone. [1,6] Some of the telltale symptoms of underactive thyroid, or hypothyroidism, include:

• A constant chill or difficulty staying warm
• Extreme fatigue
• Muscle cramping
• Constipation and other gastrointestinal problems
• Memory or concentration difficulties

Hypothyroidism can be difficult to identify during pregnancy for two reasons [3,6]:

1. Symptoms of hypothyroidism can be mild and often ignored.
2. Symptoms aren’t dissimilar to typical first-trimester discomforts of pregnancy, so pregnant people may not report them to their providers.

Hashimoto’s disease is the most common cause of hypothyroidism in pregnancy. [6] Hashimoto’s disease is an autoimmune disease like Graves’ disease in which your immune system makes antibodies that attack your own thyroid, causing inflammation and damage. This inflammation and damage make it harder for your thyroid to make the thyroid hormones and levels necessary for a healthy pregnancy (Barbor, ATA).

Hypothyroidism can also cause your body to make too much of another hormone called prolactin. Prolactin is the hormone that tells your body to make breast milk once you deliver your baby. Too much prolactin (as with hypothyroidism), can block ovulation, making it impossible for you to get pregnant. [3]

Untreated hypothyroidism in pregnancies can lead to [1,6]:

• Anemia (a lower than normal number of healthy red blood cells)
• Muscle pain and weakness (for the mother)
• Low birthweight
• Preeclampsia (a late-pregnancy, dangerous rise in blood pressure)
• Miscarriage
• Stillbirth

Pregnant people with severe or untreated hyperthyroidism may have problems with their placenta, postpartum hemorrhage (bleeding), congestive heart failure. [6]

Hypothyroidism can also have severe and life-altering consequences for the fetus. Thyroid hormones are necessary for normal brain development. If pregnant people with hypothyroidism do not receive treatment (replacement of thyroid hormones through medication during pregnancy), their babies may have severe cognitive, neurological, and developmental abnormalities.6 Routine screening of pregnant people’s thyroid hormone levels throughout pregnancy can help safeguard against such devastating consequences of hypothyroidism during pregnancy. [8]

Thyroid Diseases and Pregnancy FAQs

If you’ve had thyroid challenges and want to get pregnant, you likely have many questions. Everlywell is here to answer some of the most common questions those trying to conceive (TTC) have about thyroid health:

How Long After Starting Thyroid Medication Can I Get Pregnant?

Research shows that treating thyroid disorders (either hypo- or hyperthyroidism) improves fertility and results in successful pregnancies. [10, 11] For instance, in a 2012 study of 394 women struggling with hypothyroidism-related infertility, nearly 80% of the participants conceived within one year after starting hypothyroidism treatment. [10]

Despite this evidence, it’s hard to say how long it will take you to conceive after starting treatment for thyroid disease. Your timeline will likely depend on factors like:

• Your menstrual cycle – If your thyroid disease produces irregular menstrual cycles, it may take time for your body to adjust to regular patterns after starting treatment. Regular cycles make it easier to track ovulation, which can help you with conception timing.
• Your fertility treatments – If you’re using tools like IVF to conceive, the timing and effectiveness of these processes can also impact your conception timeline.
• Other medical conditions – Your thyroid disorder may not be the only reason why you are not getting pregnant. Male factor infertility accounts for one-third of fertility problems. [12] Sometimes even after treating your thyroid, you may need additional assistance or treatment to conceive.
• Your specific type of thyroid condition – For example, thyroid cancer is most common in women in their 20s and 30s, so their pregnancy timeline may be shifted later if they undergo either radiation therapy or surgical removal of their thyroid for treatment. People with thyroid cancer are advised to wait at least twelve months before attempting pregnancy after treatment for thyroid cancer. [13]

Can Thyroid Problems Lead to Pregnancy Loss?

Yes, unfortunately thyroid problems can lead to miscarriage in some cases. [1,6,7] Both hyperthyroidism and hypothyroidism can ultimately lead to pregnancy loss if not correctly untreated.

A miscarriage is a serious medical event with physical and mental impacts. It’s also very common—medical experts estimate that over 25% of pregnancies end in miscarriage. [14] If you’ve had a miscarriage, talk to your provider about having your thyroid levels checked — they may order a test to monitor your levels and start treatment if necessary.

Can Thyroid Problems Lead to Infertility?

Yes, thyroid problems can also lead to infertility if they are not diagnosed or treated.[1,3,6,7,11]

Medical experts believe that there are three general ways that thyroid problems can cause infertility or “subfertility” (which typically means that you are able to conceive, but it might take you longer to difficulty conceive) [8,11,15]:

• High prolactin levels – People with hypothyroidism often have high levels of thyroid releasing hormone (TRH), which can sometimes result in high prolactin levels.11,15 High levels of both can disrupt the menstrual cycle, prevent ovulation, and make it difficult to conceive.
• Anovulatory cycles – High prolactin and other hormonal abnormalities in people with thyroid diseases can also cause anovulation—a condition where your ovaries don’t release eggs. [7,11,15] And if there aren’t any eggs for sperm to fertilize, then there can’t be a pregnancy.
• Luteal phase abnormalities – The menstrual cycle can be separated into the follicular phase (before ovulation) and the luteal phase (after ovulation). [11] After an egg descends into a fallopian tube, your body produces a variety of hormones to prepare your uterus to accept a fertilized egg. But if your thyroid isn’t functioning normally, abnormal hormone production will disrupt the preparation of your womb’s lining, making it less likely that a fertilized egg will be able to implant. [16]

Seeking Treatment for Thyroid Issues Before Getting Pregnant

If you’re having difficulties conceiving and you suspect that your thyroid function may be playing a role, consider learning more about your thyroid issue and seeking treatment.

Here’s a quick overview of how to start thyroid treatment before trying to get pregnant:

1. Talk to your providers – Whether you’re already seeing a fertility specialist, working with your OB/GYN, or seeing your primary care provider, talk to them about your fertility concerns. Ask them questions about your thyroid, let them know about any family history of infertility or thyroid disease, and tell them about your symptoms, and talk to them about potentially ordering a blood test to measure your thyroid hormones.
2. Get tested – Your healthcare provider may order a thyroid screening, a blood test designed to measure your thyroid hormone levels and evaluate the health of your thyroid.
3. Get treatment – If your test results are abnormal, ask your provider about your treatment options. There are a wide variety of thyroid issues and just as many treatments. In fact, some treatments may be more compatible with your fertility journey than others, so make sure to keep your providers in the loop about your long-term conception and health goals. Make sure to talk with them about your pregnancy timeline – preconception is the ideal time to start thyroid treatment if you need it.[3,8]
4. Continue the conversation throughout your pregnancy – Thyroid health and hormone levels change over the course of pregnancy. [8] Make sure to go to all of your regularly scheduled prenatal visits, talk to your provider about any changing symptoms, and don’t hesitate to request additional thyroid tests during pregnancy to make sure your hormones are at the right levels for a healthy pregnancy.

Taking Steps to Understand Your Thyroid

Thyroid issues make getting pregnant more complicated, but not impossible.

If you’re looking for thyroid treatment, look no further than Everlywell. With licensed telehealth clinicians, prescription services, and at-home test collection kits, we can help you start to investigate your thyroid health, easily and conveniently. While Everlywell can’t provide medical care for you once you are pregnant, we can help you optimize your thyroid health and overall preconception health.

Learn more about Everlywell’s online thyroid treatment options, and start your journey to a better you today.

Related Content

What Is Thyroid Postpartum?

Thyroid and Period Changes: What's the Connection?

Does Thyroid Medication Affect the Menstrual Cycle?

References

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14. Dugas C, Slane VH. Miscarriage. National Institutes of Health. June 27, 2022. URL.Accessed June 15, 2023.
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16. Reed BG, Carr BR. The Normal Menstrual Cycle and the Control of Ovulation. National Institutes of Health. August 5, 2018. URL. Accessed June 15, 2023.