When a couple decides that it's the right time to have a child, anything that delays conception can cause distress. When the problem is due to infertility in the male, the direct cause may not always be a malfunction in his reproductive organs. Other conditions, such as hypothyroidism, could be the root cause of the problem. In many cases, correcting this disorder can restore a man's fertility.
The Thyroid Gland
Your thyroid gland is a small, butterfly-shaped organ in the front part of your neck. It makes thyroid hormone, which helps regulate your cells' use of energy from nutrients in your blood. When the thyroid gland makes too little hormone, the condition is called hypothyroidism. If a person develops hypothyroidism, the symptoms can include a general sense of fatigue, tiring easily or feeling cold even though the environment is normally warm, having itchy or dry skin, poor appetite or weight gain. Hypothyroidism is relatively common and is diagnosed in 2 to 3 percent of Americans. Because its symptoms often appear gradually, an additional 10 to 15 percent of Americans may have the condition but be unaware of it, a situation called subclinical hypothyroidism. About one-third of hypothyroidism cases arise in men; if untreated, the problem can lead to male infertility.
When a man has hypothyroidism for a period of time, the low levels of thyroid hormone can indirectly cause excess production of a pituitary hormone called prolactin. Prolactin in women helps stimulate breast tissue during pregnancy. Men also make small amounts of prolactin, but its function in men is not well understood. When a man has hypothyroidism, high levels of a thyroid-stimulating factor can also cause excess prolactin production. In large amounts, prolactin has a negative effect on the cells in the testis that make testosterone, the male sex hormone. Low testosterone can cause sperm production to fall, as shown in a study published in 2012 in the "Urology Journal," in which men with hypothyroidism were compared to normal subjects. Those with hypothyroidism had abnormally high prolactin, while their testosterone levels and sperm counts were about one-third of normal values.
Men with hypothyroidism may also develop erectile dysfunction and experience a drop in their libido, or sex drive, according to the "Urology Journal" study. Researchers found that most subjects with hypothyroidism had lower scores on a questionnaire designed to measure erectile function, although this was not true of all subjects with the disorder. Another study published in December 2005 in the "Journal of Clinical Endocrinology and Metabolism" found that more subjects with hypothyroidism had a decrease in libido, or hypoactive sexual desire, and an increased likelihood of premature or delayed ejaculation, compared to a control group. Lower testosterone might be the cause of some of these problems in hypothyroid men, but the ejaculatory disorders could also reflect a direct effect of low thyroid hormone on ejaculation, a possibility that needs further study.
Treatment and Recommendations
Once hypothyroidism is diagnosed in a man with fertility problems, bringing thyroid hormones levels back into the normal range usually restores normal erectile and ejaculatory function, according to the study in "Journal of Clinical Endocrinology and Metabolism." In most cases, other problems related to the disorder, such as low sperm count and reduced testosterone, also improve over time. Hypothyroidism is best diagnosed by measuring blood levels of thyroid hormones in a specific blood test. If you have problems with erectile function or ejaculation, or if you are having difficulty fathering a child, discuss the possibility that you are hypothyroid with your doctor or a specialist in endocrinology, who will help you determine the underlying cause of your fertility problems.
- American Thyroid Association: ATA Hypothyroidism Booklet
- Current Opinion in Obstetrics and Gynecology: Infertility and Thyroid Disorders
- Journal of Clinical Endocrinology and Metabolism: Multicenter Study on the Prevalence of Sexual Symptoms in Male Hyper- and Hypo-Thyroid Patients
- Urology Journal: The Role of Hypothyroidism in Male Infertility and Erectile Dysfunction
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