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Hormones 101: TSH in fertility testing

TSH in fertility testing – we’re telling you all about it in this blog! To help you sift through misinformed articles on the Internet, we’re writing a ‘Hormones 101’ series, explaining hormones included on our test panel. We also cover T4 in-depth here.

We empower women to be proactive about fertility health. Adia is designed by leading OBGYN, psychology and nutrition experts. We take a holistic approach to fertility. This includes both your emotional, physical health.

TSH in fertility: Why does it matter?

(In)fertility is complex. Knowing your hormone health can help you capture issues that impact conception. While a hormone test is not an absolute predictor of fertility, it’s a great tool in your preconception health plan. TSH is part of the thyroid function tests in our hormone panel. We’ve included T4 in this too. 

What are thyroid function tests? 

We look at six hormones in our expert-curated panel, including thyroid hormones (TSH and T4). Your thyroid is a small, butterfly-shaped gland in your neck. This gland regulates important functions like metabolism, energy production, and hormone levels. Therefore, thyroid dysfunction can affect your menstrual cycle, ovulation, and the potential outcomes of IVF treatment. 

What is TSH?

The pituitary gland produces thyroid stimulating hormone, or thyrotropin (TSH) to regulate thyroid hormones in your blood. The thyroid hormones are thyroxine (T4), and triiodothyronine (T3).

TSH is released when levels of these thyroid hormones decrease. The pituitary gland stops releasing TSH if thyroid hormone levels rise above the normal range. 

Why do we look at TSH in fertility tests?

The UK’s NHS doesn’t routinely carry out thyroid function tests. So, for a complete picture of fertility health, you should get thyroid hormones tested since thyroid problems can affect ovulation and your menstrual cycle. 

Hypothyroidism is when your thyroid is ‘under-active’ and not enough thyroid hormones are produced. This can cause cysts to grow on your ovaries. Hypothyroidism can lead to increased production of prolactin, which is responsible for lactation in women. High levels of prolactin can mean you may not ovulate. 

Hyperthyroidism is when you have an ‘over-active’ thyroid. Unfortunately, hyperthyroidism increases the risk of miscarriage. Miscarriage risk can be 4 times higher, as compared to that for women with normal thyroid function.

In fertility testing, TSH levels outside the normal range can indicate problems, but some variation is fine. Preconception TSH levels can affect how you respond to IVF treatment, so if you’re thinking about IVF, do get tested. Healthy thyroid function is important for women and men, because an over-active thyroid can reduce sperm count in men, thus causing infertility.

You should always tell your GP if you experience symptoms such as unintentional weight gain or loss, a difference in your ability to tolerate the heat or cold, or problems with digestion. You should also complete a thyroid function test. If thyroid problems are detected early, and you’re started on treatment, you can still conceive naturally. Thyroid treatment is likely to be safe during pregnancy, though you should always tell your doctor if you are trying to conceive.

When you complete a test with Adia, we send you a detailed report explaining your results. Consequently, you can discuss any concerns about your results with our fertility experts.

How can I maintain healthy thyroid function?

You can’t control all thyroid problems, but you can benefit from a healthy diet containing vitamins and minerals that support thyroid function. Iodine, selenium, iron, vitamin A and zinc are all helpful for a healthy thyroid.

I hope this helps explains the role of TSH in fertility testing. Please remember, you should note symptoms of thyroid disorder, and discuss these with your GP, especially if you’re trying to conceive. 

For more info on thyroid and fertility, contact our experts. Join Adia to ask an expert a question. 

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Read other blogs in our ‘Hormones 101’ series: