Understanding Thyroid Stimulating Hormone Test (TSH test) for Infertility

Quick Bites

  • Thyroid Stimulating Hormone (TSH) Test is used to check the hormone levels released by the thyroid gland
  • TSH test also provides important information about infertility
  • TSH test is done during pregnancy to check if the pregnancy is at risk or not



Thyroid has become a common disease. Earlier, this thyroid problem was more prevalent among old age people, especially women, but, because of unhealthy eating habits and lifestyle changes, a large number of young people and children are also becoming vulnerable to this disease.

A thyroid-stimulating hormone test (TSH test) is a test to identify disorders of the thyroid gland. The pituitary gland situated at the front part of your brain secretes the thyroid-stimulating hormone (TSH). The TSH activates the thyroid glands to produce triiodothyronine (T3), thyroxine (T4), and calcitonin. The hormones released from the thyroid gland are essential to maintain a healthy metabolism, hormonal balance, and proper functioning of the body. The TSH levels indicate if your thyroid is functioning normally or not.

Disturbance in thyroid functioning can also cause problems with ovulation and reduce fertility in women. While many women are aware that an imbalance of TSH, T3, and T4 hormone can cause a change in weight or mood swings, did you know that it can also impact on your menstrual cycle and fertility? In this article, we will learn about the TSH test, How it will affect your fertility?

In this article


What is a Thyroid Stimulating Hormone (TSH) Test?

The thyroid is a small butterfly-shaped gland located in front of the neck. It releases hormones that regulate numerous functions of the body like, growth and metabolism. The pituitary gland, located at the base of the brain, controls the release of hormones from the thyroid gland. It does so by producing Thyroid Stimulating Hormone (TSH). Both the glands work together as a team to make sure the right amounts of thyroid hormones are produced in your body.

TSH test is a blood test that measures the levels of TSH in your blood [1]. This test determines how well your thyroid gland is working. The test result can tell if you have an underactive thyroid (hypothyroidism), or an overactive thyroid gland (hyperthyroidism). Your fertility doctor may prescribe you TSH test to identify the cause of infertility as various researches have shown a connection between thyroid dysfunction and infertility.

Read more: Importance of Hysterosalpingography Test (HSG) in Infertility

Why is TSH test performed?

The doctor may do a TSH test to check if you have a thyroid disorder or maybe as a part of your infertility checkup. Whatever the reason might be, your doctor will make the decision depending on your symptoms.

Your doctor may ask you to get a TSH test if you show symptoms of hypothyroidism or hyperthyroidism. The most common symptoms of hypothyroidism are weight gain, muscle weakness, increased sensitivity to cold, constipation, fatigue, impaired memory, slowed heart rate, and irregular or heavy periods.

The most common symptoms of hyperthyroidism are increased heart rate, pounding of the heart (Heart palpitations), sweating, thinning of the skin, trembling in your hands and fingers, and irregular or no periods (amenorrhea).

Hypothyroidism: Hypothyroidism (underactive thyroid) is a medical condition, where the thyroid gland is not able to produce enough thyroid hormone, needed for the normal functioning of the body [2]. It is caused by:

  • Hashimoto’s disease: which is an autoimmune disease that causes the body to attack the thyroid cells due to which the thyroid gland doesn’t produce enough hormones.
  • Postpartum thyroiditis: It is temporary thyroiditis that may develop in women after childbirth.
  • Thyroiditis: It is an inflammation in the thyroid gland.
  • Iodine Deficiency: The thyroid gland uses iodine to produce hormones. Iodine deficiency can lead to an underactive thyroid.

Hyperthyroidism: Hyperthyroidism (overactive thyroid) is a condition, where the thyroid gland starts producing large amounts of thyroid hormones. It is caused by:

  • Graves' disease which is an autoimmune disorder and it is also the most common cause of hyperthyroidism
  • Excess iodine
  • Thyroiditis
  • Benign (harmless) tumors in the thyroid or pituitary gland, etc

Both hyperthyroidism and hypothyroidism can affect ovulation in women causing issues in natural conception. Also, abnormal levels of thyroid hormone can lead to pregnancy loss, premature birth, infant death, and many more. Hence, many doctors are nowadays performing this test as a part of the infertility test screening as well.

Read more:Estradiol (E2) Hormone Test and its effect on fertility

How is a thyroid stimulating hormone test (TSH test) performed?

A TSH test is a blood test hence it requires a blood sample. Your doctor will take your blood sample through an injection usually from the inner side of the elbow. The entire process is usually over within 5 minutes.

The procedure takes place in the following order:

  • The doctor starts with cleaning the area from where he plans to take the blood with an antiseptic or other sterilizing solution
  • The doctor will then tie your arm with an elastic band so that your veins swell with blood (this makes it easier for them to find your vein)
  • Once they find the vein they will use an injection to draw the blood
  • The blood is put in a small tube
  • They will remove the elastic band and wipe the area with cotton and put a bandage to stop the bleeding

TSH is a blood test and no special preparation is required prior to this test. Your doctor may ask you to stop eating several hours before this test. Apart from this, there is nothing that you need to do from your side. Any additional information will be given to you by your doctor.

Read more:Free Thyroxine (T4) test: Things you need to know before getting tested

Interpreting the TSH test results

The normal range or TSH levels in our body is 0.4 to 4.0 milli-international units per liter (mU/L). If you are suffering from some thyroid disorder, then your TSH levels might be within 0.5 to 3.0 milli-international units per liter (mU/L).

If the results of the TSH test show a high level of TSH, then your thyroid is underactive, and you may have hypothyroidism. When the thyroid gland is not producing enough thyroid hormones, the pituitary gland releases more TSH to push the thyroid gland to make more hormones.

If the results of the TSH test show a low level of TSH, then your thyroid is overactive, and you may have hyperthyroidism. When the thyroid gland is producing too many hormones, the pituitary gland releases less TSH.

Many studies have shown that normal levels of TSH may vary according to age. The table below is the estimated normal levels of TSH (in milli-international units per liter) according to a specific age group.

Age Group

Normal Level

High Level

Low Level

18–30 years

0.5–4.1 mU/L

Above 4.1 mU/L

Below 0.5 mU/L

31–50 years

0.5–4.1 mU/L

Above 4.1 mU/L

Below 0.5 mU/L

51–70 years

0.5–4.5 mU/L

Above 4.5 mU/L

Below 0.5 mU/L

71–90 years

0.4–5.2 mU/L

Above 5.2 mU/L

Below 0.4 mU/L

Read more:Importance of Testosterone Hormone Test in Fertility

Connection between TSH level and fertility

Various research suggests links between thyroid dysfunction and infertility and delayed conception. Infertility is the inability to conceive after 12 months of regular intercourse without any protection. About 42 million people suffer from thyroid diseases (hypothyroidism and hyperthyroidism) in India.[3] As discussed earlier, high TSH level means your thyroid is not making enough thyroid, a condition called hypothyroidism. Whereas low TSH level means your thyroid is making too much hormone, a condition called hyperthyroidism.

Thyroid dysfunction and female infertility:

Hypothyroidism (shown by high TSH level) can cause ovulation problems, irregular periods, and sex hormone imbalance (estrogen and progesterone) leading to infertility issues[4]. Hypothyroidism affects about 2-4% of reproductive-age women.

Likewise, low levels of TSH (showing hyperthyroidism) can also cause infertility issues like missed periods. Hence a TSH test is needed to rule out thyroid disease as a factor contributing to infertility in women.

A recent study has also concluded that higher levels of TSH are linked with unexplained infertility in women. The study took on a total of 239 women out of which 189 had unexplained infertility, and 53 were not getting pregnant due to their partner’s infertility (male infertility). The study found that women who were suffering from unexplained fertility had significantly high levels of TSH [5].

Thyroid dysfunction and male infertility:

In men, hyperthyroidism (shown by a low level of TSH) can cause issues like low sperm volume, reduced sperm density, changes in the size and shape of the sperm, and low sperm motility.

Hypothyroidism, though found more in women as compared to men, can also affect fertility in men. Many studies have concluded that high TSH levels can adversely affect semen quality by compromising semen motility and semen volume. Hence a TSH test as a part of infertility checks up in males can also answer any questions about their fertility issues.

Read more:Luteinizing Hormone Test and Its Importance in Fertility

TSH level during pregnancy

Diagnosing abnormal thyroid function during pregnancy is crucial for the welfare of the mother and the fetus.[6] High levels of TSH in pregnant women may also lead to infant death, premature birth, and lower infant intelligence. Hence, TSH tests can also help monitor your pregnancy and keep pregnancy risks at bay.

The TSH levels (in milli-international units per litre) during pregnancy between the ages of 18 to 45 years is given below,

Pregnancy Stage

Normal Levels

High Level

Low Level

First trimester

0.6–3.4 mU/L

Above 3.4 mU/L

Below 0.6 mU/L

Second trimester

0.37–3.6 mU/L

Above 3.6 mU/L

Below 0.3 mU/L

Third trimester

0.38–4.0 mU/L

Above 4.0 mU/L

Below 0.3 mU/L

Thyroid hormone production increases in pregnancy to overcome this woman's need to increase iodine intake.[7] Your doctor will look at the TSH level and provide you medications to treat any issues with thyroid during your pregnancy if needed.

Read more:Progesterone Test and Its Importance in Female Fertility

Can I control Thyroid Stimulating Hormone (TSH) levels naturally?

TSH levels low or high can be managed at home. If you follow a certain routine and diet you may be able to manage your TSH levels reducing your chances of suffering from any of the conditions related to TSH levels.

If you suffer from high TSH levels (Hypothyroidism) you can follow the measures mentioned below to manage the TSH levels.

  • If you have high TSH levels, eating sugar can worsen your symptoms. Try to follow a sugar free diet. You may switch to synthetic sugar but even they have some side effects hence it is advised if you can slowly move away from food containing sugar.
  • Iodine deficiency can cause high TSH levels. Hence it is necessary to add iodine rich food in your daily diet. Foods like iodine salt, banana, yogurt, sweet potato, tuna, milk, shrimp, sardine, etc are rich in iodine.
  • Studies have found that zinc can also help manage TSH levels in the body. You can include zinc rich food like eggs, dark chocolate, oats, red meat (beef, lamb, pork), chickpeas, pumpkin seeds, etc in your daily diet.

If you suffer from low TSH levels ( (Hyperthyroidism) you can follow the measures mentioned below to manage the TSH levels.

  • Low TSH levels can be the result of excess iodine in your body. Hence avoid eating foods that are high in iodine.
  • Lemon balm is a herb which can also help curb TSH low levels. You can find the leaves and roots of lemon balm in many herbal and online shops.
  • Glucomannan is a dietary fibre and many studies have found it to be helpful in managing low levels of TSH. Glucomannan supplements are available online as well as in pharmacies. The supplements are usually in the form of tablets, capsules and powder.

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List of ReferencesHide

1 .

Medlineplus.gov. “TSH (Thyroid-stimulating hormone) Test”. Medlineplus.gov, 25 March 2020.

2 .

Mayoclinic.org. “Hypothyroidism (underactive thyroid)”. Mayoclinic.org, 07 January 2020.

3 .

Ambika Gopalakrishnan Unnikrishnan and Usha V. Menon. “Thyroid disorders in India: An epidemiological perspective”. Indian J Endocrinol Metab. 2011 Jul; 15(Suppl2): S78–S81, PMID: 21966658.

4 .

Indu Verma, Renuka Sood, et al. “Prevalence of hypothyroidism in infertile women and evaluation of response of treatment for hypothyroidism on infertility”. Int J Appl Basic Med Res. 2012 Jan-Jun; 2(1): 17–19, PMID: 23776802.

5 .

Tahereh Orouji Jokar,1,2,* Lindsay T. Fourman, et al. “Higher TSH Levels Within the Normal Range Are Associated With Unexplained Infertility”. J Clin Endocrinol Metab. 2018 Feb; 103(2): 632–639, PMID: 29272395.

6 .

Kumar A, Gupta N, et al. “Thyroid function tests in pregnancy”. Indian J Med Sci. 2003;57(6):252-258, PMID: 14510343.

7 .

Leung AM. “Thyroid function in pregnancy”. J Trace Elem Med Biol. 2012;26(2-3):137-140, PMID: 22658718.

Last updated on: : 28 Sep 2020

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