Thyroid Stimulating Hormone (TSH) is a hormone produced in the brain that stimulates the thyroid gland. The thyroid gland is located in the front of the neck and is involved in metabolism.

Your TSH level is measured by taking a blood test that shows how the thyroid gland is working.

TSH measures how much hormone the brain needs to make for your thyroid gland to work properly. If your thyroid gland is not working properly, it is either overactive or underactive. An underactive thyroid is called hypothyroidism and can result in the brain producing large amounts of a hormone called prolactin. Too much prolactin (or hyperprolactinemia), is not life threatening, but can sometimes cause irregular menstrual cycles and infertility.

If your blood tests show that you have hypothyroidism, your provider can talk to you about prescribing medication to correct the condition. When the thyroid is working properly, menstrual cycles and ovulation should become more regular, making it easier to get pregnant. Keep in mind that there may be other reasons why you are not getting pregnant. Your provider will be doing many tests to determine the reason(s).

Measuring the TSH is an important blood test in the initial blood tests for infertility.