Thyroid and Fertility

how thyroid disorders can cause infertility

Your thyroid, a small gland at the base of your neck which secretes metabolic hormones, may be the last thing you would suspect when you are having issues with infertility. Fortunately, the experienced physicians at Dallas-Fort Worth Fertility Associates know that thyroid disorders can affect a woman’s fertility, and they will work with you to diagnose and treat any thyroid problems you may be having, including hypothyroidism and hyperthyroidism.

doctors and nurses discussing thyroid disorder

Both hypothyroidism and hyperthyroidism can cause infertility by affecting ovulation. Women with these conditions may not release an egg once a month during menstruation; in fact, they may not release an egg at all. This makes it difficult to conceive.


What is Hypothyroidism?

When the thyroid gland produces less thyroid hormone than it should, the thyroid disorder is called hypothyroidism, or underactive thyroid. While some women may not initially experience any symptoms, as the condition progresses, hypothyroidism can cause:

  • Lack of energy and fatigue
  • Weight gain
  • Constipation
  • Dry and/or itchy skin
  • Sensitivity to cold
  • Depression
  • Hoarse voice
  • Less interest in sex
  • Irregular periods
  • Infertility problems
  • Recurrent miscarriages

What is Hyperthyroidism?

When the thyroid produces too much thyroid hormone, that thyroid disorder is known as hyperthyroidism, or overactive thyroid. Symptoms, which may not be observed during the early stages, include:

  • Nervousness and anxiety
  • Fast heart rate or palpitations
  • Sensitivity to heat
  • Weight loss
  • Insomnia
  • Shaking or tremors
  • Excessive sweating
  • Neck tenderness

Diagnosing Thyroid Disorders during Infertility Treatment

The first step in diagnosing thyroid disorders is a blood test that measures thyroid stimulating hormone (TSH). TSH levels are very important in helping to diagnose thyroid disorders. If the TSH level is too high, it may indicate that the patient has an under-active thyroid or hypothyroidism. If it is too low, it may mean that the patient has hyperthyroidism, or an overactive thyroid. Typically, the normal range for TSH is 0.5 to 5.5*, but your fertility specialist will evaluate these ranges, based on your symptoms.

When the TSH blood test produces abnormal results, this test may be followed up by a full thyroid panel, which evaluates levels of thyroxine (T3 and T4), as well as checks for thyroid antibodies.

What Is the Treatment for Thyroid Disorders?

Hypothyroidism is usually treated with thyroid replacement therapy. This is achieved with medication that supplies and regulates the thyroid that the body is not currently producing in the correct amount.

Hyperthyroidism is also treated with medications, but these medications are used to decrease production of the thyroid hormone, which is being produced in excess. The medications also inhibit the secretions of thyroxine (T3 and T4). In addition, physicians have to locate the source of the increased thyroid hormone production so they can destroy it using radioactive iodine.

If you are experiencing symptoms of thyroid disorders like hypothyroidism or hyperthyroidism, schedule a consultation with the reproductive endocrinologists at Dallas - Fort Worth Fertility Associates to learn more about how these conditions may be contributing to infertility.

*The above TSH range has been adopted by the American Society of Reproductive Endocrinology as the normal range for pregnant women. ACOG has not adopted this range, but instead uses 0.5-2.5 as the normal TSH range in pregnant women.