The thyroid gland is an endocrine gland in the front of the neck that produces thyroid hormones to regulate the body’s metabolism. Through the hormones it produces, the thyroid gland influences almost all the metabolic processes in your body.  

“The relationship between the thyroid and infertility is impacted if your hormones become imbalanced,” shares Dr. Jessica Selter, an SGF physician who cares for patients in our K Street, Washington, D.C., location. “This can have a negative impact on reproductive health, making it difficult to achieve a pregnancy.”  

3 ways the thyroid affects fertility 

1). Hyperthyroidism and hypothyroidism

If you have hyperthyroidism (overactive thyroid), the thyroid gland produces too many hormones. If you have hypothyroidism (underactive thyroid), the thyroid doesn’t produce enough hormones. In both situations, researchers have found a direct correlation with these hormone imbalances and infertility. 

2). Low levels of a thyroid hormone

Inadequate levels of a thyroid hormone can prevent ovulation or an egg from being released for fertilization. If there is not an egg present, conception cannot occur. 

Aside from having difficulty conceiving, an underactive thyroid can pose challenges for carrying a pregnancy to full term. Women with hypothyroidism are more susceptible to miscarriages compared to women with normal hormone levels.

3). General thyroid disorders

In some cases, thyroid disorders can be overlooked especially in patients with a diagnosis of unexplained Infertility. It’s important for physicians to ask the right questions and conduct appropriate tests to see if thyroid disease could be a contributing factor.  

“At Shady Grove Fertility, as part of a patient’s initial workup, we perform a series of hormonal testing to determine any causes for a person’s infertility,” shares Dr. Selter. “Our physicians perform these tests because hormones control every step of achieving a pregnancy. Based on the results, our physicians then determine an appropriate treatment plan for your individual needs.”  

When to Seek Help

It is recommended to seek a full thyroid evaluation if you have experienced: 

  • Inability to conceive after 1 year if you are less than 35, and 6 months if 35 or older
  • Two or more miscarriages
  • Irregular menstrual cycles
  • Family history of thyroid disorders

There are other reasons why a person might have infertility that might not be attributed to thyroid disease. However, if symptoms of hypothyroidism or hyperthyroidism are present, we recommend a thyroid screening. 

Once underlying thyroid issues are treated, generally with medication, and hormones return to adequate levels, a women’s fertility may be restored. If this is not the case, it’s important to seek help from a reproductive endocrinologist to see if there are any other underlying factors as to why pregnancy has not occurred. 

For more questions about the relationship between thyroid and infertility, or to schedule an appointment, please speak with one of our New Patient Liaisons at 1-877-971-7755.  

Medical contribution by Jessica Selter, M.D. 

Jessica Selter, M.D. earned her undergraduate degree from Duke University in Durham, North Carolina as a Neuroscience major. She then became a researcher at the National Institutes of Health in Bethesda, Maryland before earning her medical degree with distinction from the Johns Hopkins University School of Medicine in Baltimore, Maryland.

Editor’s note: This article was originally published in March 2016, and has been updated for accuracy and comprehensiveness as of January 2024.