Thyroid issues are pretty common but often slip under the radar until they start impacting fertility. Women are more likely to have thyroid problems than men. In fact, about one in eight women1 will experience this at some point in their lives.

The thyroid, a butterfly-shaped gland, churns out hormones that are super important for things like our metabolism, breathing, body temperature, and heart rate. Hypothyroidism happens when the thyroid doesn't release enough of these hormones into your bloodstream. This can mess with fertility by affecting ovulation, implantation, and hormone levels.

But don't worry. There's a bright side, even if you're dealing with hypothyroidism. With the proper treatment and management of this condition, you can actually boost your fertility chances, setting yourself up for a successful pregnancy journey!

In this guide, we’ll dive into the links between hypothyroidism and fertility, discuss how to improve your thyroid health, and give you some tips to boost your chances of conception. Let’s get started.


What is Hypothyroidism?

Hypothyroidism,2 sometimes called underactive thyroid, happens when the thyroid gland produces less thyroid hormones than it should. This causes your metabolism to slow down, leading to issues with your entire health and body. In its early stages, hypothyroidism may not cause any noticeable symptoms. However, when untreated or poorly managed, it can cause problems, including:

  • Fatigue or lethargy
  • Weight gain
  • Sensitivity to cold 
  • Thinning hair
  • A puffy face or neck
  • Depression
  • Hoarse voice
  • Low libido
  • Joint and muscle pain
  • Irregular periods
  • Infertility problems
  • Recurrent miscarriages

There can be many reasons why your thyroid can’t make enough thyroid hormone. Common causes of hypothyroidism include:

  • Hashimoto’s disease, which is the most common cause of hypothyroidism. It is an autoimmune disorder where your immune system attacks your thyroid. 
  • Thyroiditis, an inflammation of the thyroid
  • Congenital hypothyroidism, or hypothyroidism that’s present at birth 
  • Surgical removal of part of all of the thyroid
  • A family history of thyroid conditions or autoimmune diseases
  • Radiation treatment of the thyroid and some types of chemotherapy
  • Certain medications, including iodine-containing medications, lithium, and amiodarone


Can Hypothyroidism Cause Infertility?

The link between hypothyroidism and infertility is multifaceted, meaning that hypothyroidism and low thyroid hormone levels can affect many different aspects of your menstrual cycle and ovulation process. 

The thyroid gland produces several hormones, two of which are directly linked to ovarian function: thyroxine (T4) and triiodothyronine (T3).3 These hormones bind to receptors in your ovaries and influence everything from egg growth and maturation, progesterone and estrogen production, egg fertilization, and an embryo’s viability during the early stages of development.

Low levels of T4, the primary thyroid hormone, can lead to high prolactin. levels4 Prolactin, as the name suggests, is a hormone associated with lactation or breast milk production. Under normal conditions, a woman’s body produces very little prolactin unless she’s pregnant. High levels of prolactin, however, can sometimes slow down or even stop ovulation altogether.5

Hypothyroidism can also cause a shortened luteal phase,6 which is the second half of the menstrual cycle. The luteal phase lasts from ovulation to menstruation and usually is 12 to 16 days long. It is considered short when it lasts fewer than 10 days. A short luteal phase can cause fertility problems because it doesn’t allow enough time for the uterine lining to build up sufficiently for the embryo to attach to the womb, making it difficult for a fertilized egg to be implanted or causing an early miscarriage. 

Moreover, some experts suggest that another reason why thyroid and fertility may be associated is that hypothyroidism seems to affect the quality of cervical mucus,7 which plays a crucial role in sperm transport and survival within the female reproductive tract. 

But as well as directly affecting ovulation, hypothyroidism can also impact fertility indirectly. For instance, a study8 looking at 30 women with subclinical hypothyroidism showed that the condition may contribute to insulin resistance, a condition where the body’s cells become less responsive to insulin. Insulin resistance can cause elevated insulin levels in the blood. 

This can disrupt the normal function of the ovaries and hormone production, potentially affecting ovulation and the regularity of menstrual cycles. Women who have hypothyroidism are also more likely to have polycystic ovarian syndrome9 (PCOS), a condition closely related to insulin resistance. 

Subclinical Hypothyroidism: A Potential Hidden Cause of Infertility and Thyroid Problems

Subclinical hypothyroidism10 is a condition in which the levels of T4 on a blood test fall within the normal range, but the levels of thyroid stimulating hormone (TSH) are slightly elevated. This implies that while you technically don’t have hypothyroidism, your thyroid isn’t working as well as it should. 

Some women with subclinical hypothyroidism may experience mild symptoms, such as fatigue and unexplained weight gain. However, in most cases, there are no signs or symptoms other than difficulty getting or staying pregnant. 

It has been found that subclinical hypothyroidism is associated with thyroid infertility, and a higher risk of miscarriage and preterm delivery. It is also linked to lower ovarian reserve in women over 35,11 and lower success rates with in-vitro fertilization (IVF). In some cases, there could be up to 50% fewer fertilized eggs during the IVF process.12 

If you're having trouble conceiving but your thyroid test results are normal, consider talking to your doctor about subclinical hypothyroidism. This condition could be an underlying factor impacting your fertility, and your doctor can help explore this possibility.

Hypothyroidism in Male Fertility

Hypothyroidism not only affects female fertility but can also have significant effects on male reproductive health. Studies13 have shown that thyroid hormones play a role in sperm production, maturation, and function. As a result, thyroid function disruptions can lead to abnormalities in sperm count, volume, motility, and morphology, which are critical factors in achieving a successful pregnancy. Plus, there’s some evidence that hypothyroidism can also affect libido and erectile function,14 which may further contribute to fertility challenges in men. 


Can You Get Pregnant with Hypothyroidism?

Since hypothyroidism and fertility are so closely connected, it’s common to wonder, does hypothyroidism cause infertility? And the answer is no. Hypothyroidism, including subclinical hypothyroidism, can significantly affect key fertility factors like ovulation and sex hormone balance, especially if it's undiagnosed or not well-managed. However, the condition won’t necessarily make you infertile or unable to achieve a pregnancy. With proper treatment, the majority of women with hypothyroidism go on to have healthy, full-term pregnancies,15 whether naturally or with reproductive assistance. 


Getting Pregnant with Hypothyroidism: What You Need to Know

If you have hypothyroidism and are planning to conceive, it’s essential to prioritize preparing your body for a healthy pregnancy and baby. Here are a few essential steps to improve your chances of a successful pregnancy. 

Talk To Your Doctor About Treatment

If you’ve been diagnosed with hypothyroidism or subclinical hypothyroidism, there’s no reason why you shouldn’t have a healthy pregnancy and baby. However, it’s important to have a conversation with your doctor about the best course of treatment for your individual situation. 

Untreated hypothyroidism can have serious implications for both fertility and pregnancy,16 such as difficulty conceiving, miscarriage, premature birth, and low birth weight. Informing your doctor a few months before trying to conceive will ensure that your thyroid hormone levels are within the normal range to reduce potential complications before and during pregnancy. 

Monitor TSH and T4 Levels

Keeping an eye on your thyroid function through regular blood tests is a must for managing hypothyroidism and optimizing fertility. 

If you have hypothyroidism, your healthcare provider may recommend regular thyroid blood tests at intervals to track changes in thyroid hormone levels over time. Based on these results, your doctor may adjust your medication dosages as necessary to maintain thyroid hormone levels within the optimal range for fertility and pregnancy.

Besides regular blood tests, looking for signs or symptoms of thyroid dysfunction like fatigue, weight gain, or mood changes is important. If you notice anything unusual, be sure to report it to your doctor promptly. This way, you can get timely intervention and adjustment of treatment if necessary.

Use Fertility Supplements

If you and your partner have both checked your thyroids and fertility labs, supplements may be a great addition to your conception efforts. 

Several vitamins and minerals have been shown to have potential benefits in improving thyroid function and enhancing fertility, such as supplements containing iodine, selenium, zinc, and vitamin B12. 

Iodine is a crucial component of thyroid hormones, while selenium can help reduce inflammation in the thyroid gland. Zinc, on the other hand, is essential for proper hormone balance and reproductive function. Additionally, vitamin B12 is necessary for healthy ovulation and sperm production.

Adopt a Nutrient-Rich Diet 

Eating a nutrient-dense, well-balanced diet is vital for maintaining thyroid health and supporting fertility, especially for individuals with hypothyroidism. Consuming foods rich in nutrients such as iodine, selenium, zinc, magnesium, and omega-3 fatty acids can help optimize reproductive outcomes and support thyroid function.

Iodine: This essential nutrient is vital for thyroid hormone production. It’s found in seafood, seaweed, and iodized salt. However, you should always balance iodine intake with selenium17 to avoid potential imbalances. 

Selenium: Essential for converting inactive thyroid hormones into their active form, selenium is found in foods like organ meats, seafood, eggs, fortified cereals and breads, and Brazil nuts.

Zinc: Key for hormone production and thyroid health, zinc can be found in oysters, red meat, poultry, whole grains, and legumes.

Omega-3 fatty acids: Well-known for their anti-inflammatory properties, which are beneficial for autoimmune thyroid conditions like Hashimoto’s. Sources include fatty fish such as wild salmon, sardines, anchovies, and plant-based options like chia seeds, flaxseeds, walnuts, edamame, and Brussels sprouts.

Magnesium: Vital for overall well-being and thyroid health, magnesium is present in dark chocolate, various grains, soy products, pumpkin and chia seeds, and leafy greens such as spinach, kale, and collard greens.

Manage Stress 

Managing stress is vital when it comes to optimizing your fertility and maintaining your thyroid health. Stress can exacerbate symptoms of hypothyroidism, interfere with your menstrual cycles, disrupt ovulation, and impair hormone production, making it more challenging to conceive.18

Fortunately, there are simple ways to lessen stress that can easily fit into your daily routine. For instance, regular physical activities such as yoga, walking, or swimming help reduce stress and prepare your body for pregnancy. Additionally, mindfulness practices like meditation, deep breathing exercises, and progressive muscle relaxation can effectively manage stress levels.

Creating a supportive environment and reaching out to friends, family, or support groups can offer emotional support, which is crucial in mitigating stress, particularly when trying to conceive. Remember, seeking help and leaning on your loved ones for support is okay.

Balance Blood Sugar

Maintaining adequate sugar levels is vital for thyroid health and fertility. One of the best ways to promote stable blood sugar levels is by eating regular meals that include a balance of quality protein, healthy fats, and fiber. Limiting refined carbohydrates and sugary foods can promote blood sugar balance. Here are some examples:

Quality protein:

  • Lean meats, such as chicken and turkey
  • Fish, such as tuna and salmon
  • Beans, peas, and lentils
  • Nuts and seeds, such as walnuts and pumpkin seeds
  • Soy products, such as tofu and tempeh

Healthy fats:

  • Olive oil
  • Olives
  • Fatty fish
  • Whole eggs
  • Avocado
  • Nut and seed butter
  • Full-fat, unsweetened yogurt


  • Broccoli
  • Beans
  • Apples
  • Bananas
  • Berries
  • Whole grains
  • Almonds
  • Lentils

By incorporating these foods into your diet, you can maintain stable blood sugar levels, which is beneficial for your thyroid health and fertility.


Boost Fertility with Fertility Smart

Grasping how thyroid health, especially hypothyroidism, affects fertility can really boost your odds of conception and having a healthy pregnancy. When you manage your thyroid condition properly, you're well on your way to improving your fertility.

At Fertility Smart, our female and male fertility supplements are expertly formulated to support your reproductive health. Our award-winning products are backed by scientific evidence and crafted by fertility experts based on the latest fertility nutrition research. Get your body the support it needs. Explore our products today! 



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