Sometimes, fertility problems can be caused by issues that aren’t directly related to the reproductive system. Many couples facing unexplained fertility struggles are surprised to learn that the thyroid, a small gland situated far away from the reproductive organs, can play a big role. Thyroid disorders often go unnoticed, but they can quietly affect hormones that are important for ovulation, menstrual cycles, and even pregnancy. If you're trying to conceive and nothing seems to be working, it may be time to look beyond the obvious and see if the thyroid and fertility connection could be the missing piece.
In this article, we take a quick look at the link between thyroid and fertility and why it is imperative to get tested early, preferably before trying to get pregnant.
Unlike reproductive organs that are located in the lower half of the human body, the thyroid is a small gland situated in the neck. It is actually shaped like a butterfly! The thyroid gland is a part of the endocrine system, and its primary function is to regulate the body’s metabolic rate. Apart from this, it also produces and releases thyroid hormones, such as calcitonin, T3 (triiodothyronine), and T4 (thyroxine). These hormones are absolutely vital, as they play a pivotal role in regulating numerous bodily functions, such as body temperature, heart rate, digestion, breathing and fertility. Any impairment or disease of the thyroid gland can have adverse effects on any or all of these functions.
Let’s take a closer look at the types of thyroid diseases to better understand how thyroid affects fertility.
Thyroid diseases can disrupt the rate at which metabolism occurs and can be categorised into two types:
Hyperthyroidism is a thyroid disease in which excess thyroid hormones are produced and released by the thyroid glands, hence earning the alternate name “overactive” thyroid gland. This results in faster metabolism than normal. The leading causes behind its occurrence are as follows:
An overactive thyroid gland is a cause of concern. Typically, hyperthyroidism causes numerous health issues, such as goitre or swelling of the neck, faster heart rate, high blood pressure, inexplicable weight and hair loss, etc. However, what many don’t realise is that it can also interfere with fertility.
Hyperthyroidism can disrupt the reproductive functions of both women and men, consequently impairing fertility and conception. In both sexes, changes in proteins such as sex hormone-binding globulin (SHBG) can disrupt the balance of key reproductive hormones.
In females, one of the first signs may be changes in the menstrual cycle, with periods becoming irregular or even absent altogether. This is especially evident in cases where the overactive thyroid gland is due to Graves’ disease. Hyperthyroidism can also interfere with ovulation, as it may trigger the excess production of certain hormones, such as prolactin. In a few cases, hyperthyroidism has been known to lead to early menopause, thus shortening the natural fertility window.
For males, hyperthyroidism can affect the quality of sperm and issues such as low semen volume, abnormal sperm shape, and reduced sperm motility have been known to occur as well.
In contrast to hyperthyroidism, hypothyroidism occurs when the thyroid gland becomes “underactive” and produces extremely low levels of thyroid hormones. This results in a slower-than-normal metabolism. Hypothyroidism is caused by:
Hypothyroidism is quite treatable. However, without treatment, this disorder could prove to be fatal. The main symptoms to be on the lookout for include fatigue, high blood cholesterol levels, muscle weakness, unexplained weight gain, mood swings, and tingling sensations in the hands. Both hyperthyroidism and hypothyroidism are fertility-impacting thyroid disorders and pregnancy chances are slim if they are left untreated.
Just like hyperthyroidism, hypothyroidism can affect the fertility of both men and women, thus hindering the chances of successfully conceiving a baby. Hashimoto’s Disease, one of the causes behind the occurrence of hypothyroidism, has been known to result in decreased libido and infertility.
In women, low thyroid hormone levels can disrupt the menstrual cycle in several ways. Periods may become irregular, excessively heavy, or stop altogether. This happens because the hormones responsible for ovulation and cycle regulation can become imbalanced. The uterine lining may also thicken abnormally, leading to unpredictable shedding and reduced chances of successful implantation.
There could also be a shortened luteal phase, which refers to the second half of the menstrual cycle. Because of this, a fertilised egg might not have enough time to attach to the womb. There’s also a higher risk of ovarian cysts and elevated thyroid antibodies, which can increase the chances of miscarriage or hinder pregnancy altogether.
Men suffering from hypothyroidism may have low sperm count and reduced levels of semen. They could also suffer from reproductive health issues like low testosterone and erectile dysfunction.
When trying to conceive a baby, it is absolutely crucial to screen for any potential issues that could hinder the chances of a successful pregnancy. This is why it is best to opt for thyroid hormone testing for fertility problems to be properly evaluated. Early diagnosis and treatment can immensely improve fertility issues.
To evaluate thyroid hormone levels, blood tests will be performed. Abnormal results will show if the person has excess or diminished levels, the former of which will indicate hyperthyroidism while the latter would indicate hypothyroidism.
Typical thyroid blood tests involve testing the levels of:
Also known as thyrotropin, the pituitary gland produces this hormone, which then travels to the thyroid gland. Its main purpose is to stimulate the thyroid gland into producing the thyroid hormones T3 and T4. Most thyroid tests will measure TSH levels first.
Detailed thyroid tests will check for the levels of primary thyroid hormones triiodothyronine (T3) and thyroxine (T4).
Autoimmune diseases like Graves’ disease and Hashimoto’s disease, which cause thyroid diseases, will be confirmed by the presence of thyroid antibodies.
Awareness is key while dealing with fertility issues, as they could be caused by disorders not just limited to the reproductive organs. Thyroid diseases like hypothyroidism and hyperthyroidism are often overlooked while evaluating reproductive health. Early diagnosis through hormone testing will ensure a higher chance of successful conception.
