Can my Thyroid Problems Affect my Fertility?

Eloise Edington  |  1 Feb 2022

We’ve all heard of an under- or overactive thyroid but how does the thyroid affect fertility?

Questions about the thyroid and fertility crop up frequently in our Fertility Help Hub community (download the free app here).  So earlier this month, Founder of FHH, Eloise, spoke with Medical Director at San Francisco’s Laurel Fertility Care, Dr. Smikle, to answer your questions about how the thyroid gland can affect fertility, optimal TSH levels and more.

Laurel Fertility Care (view their profile here) provide personalised, expert care to their patients.  To speak with one of LFC’s fertility experts from the comfort of your own home, book an introductory call via their website (here).

As we find out from Dr. Smikle, understanding the impact the thyroid has on fertility and making subsequent lifestyle changes, can help on your TTC journey.  So if you missed the IG Live, read on to have your questions about thyroid and fertility answered.

Over to Laurel Fertility Care…

How can my thyroid affect my fertility?

The thyroid is a small gland located in the neck that releases hormones vital to controlling the body’s metabolism. When functioning properly, it produces and regulates hormones in the bloodstream. Hormone imbalances caused by an overactive (hyperthyroidism) or underactive (hypothyroidism) thyroid gland can affect energy levels, weight and mood, but they can also affect your fertility.

What are the causes of my under- or overactive thyroid? Is it hereditary?

There are times when it can be hereditary. For example, some people have Graves’ Disease, where you have what we’d call a hyperactive thyroid gland. In this case, the body starts making antibodies against the thyroid gland that lowers TSH levels that can cause some people to feel bouncy and energetic.

How can my thyroid affect my fertility

What is an optimal TSH level for fertility?

In general, a normal range for TSH levels are around 3 to 3.5. If you’re trying to get pregnant or are looking at managing your thyroid hormones during pregnancy, you want a level between 1 and 2.4. If it’s low, that means you may end up having a hyperactive thyroid that we would have to address. If it’s too high, that means your thyroid activity is low.

Both an overactive thyroid and an underactive thyroid affect the fetus as it develops, and both need to be managed because of the consequences it can have on a pregnancy. Low TSH levels can cause miscarriages, and high levels— especially further along in the pregnancy—can pass through the placenta and affect the fetus.

Can I find out my thyroid levels?

If you’ve been struggling to conceive or have undergone fertility treatment in the past, you may be familiar with thyroid-stimulating hormone (TSH). It is part of the blood panel drawn at the beginning of your fertility treatments to ensure optimal levels for treatment and pregnancy. However, regular screening of thyroid hormone levels is not routine for people of reproductive age who aren’t experiencing symptoms associated with thyroid dysfunction.

I have thyroid problems – what treatment options are available?

Diet can affect the thyroid gland and there are things you can incorporate into your diet to support the thyroid – such as iodine or iodized compounds. Before iodized salt was as common as it is today, we had many more patients with thyroid symptoms. Most salts today have iodine in them, which can help manage the thyroid gland.

If you have hyperthyroidism, you have too much stimulation of the thyroid gland and we want to avoid iodized salts. Avoid shellfish and other seafoods like kelp and sushi to help thyroid problems – iodine supplements should also be avoided.

On the other hand, if you have hypothyroidism, you’d want to add more fish, iodized salts and/or supplements into your diet to help support the thyroid.

What treatment options are available for thyriod problems

I don’t have a thyroid – will this affect my fertility?

Someone who has a goiter, meaning there is a growth on the thyroid, may end up having to have their thyroid gland removed. That patient could be managed using Synthroid.

If there is a cancerous or pre-cancerous lesion in the thyroid, this can also cause the thyroid to be removed.

These situations can be quite easily managed, because there isn’t anything being administered to the body from the thyroid to counteract.

Can I improve my thyroid through diet and supplements alone?

Yes, you can manage some symptoms if they are what we call borderline. Someone who is hypothyroid can make dietary changes that will help. If it’s too high, where we’re seeing TSH levels over 5, it’s unlikely that diet changes will be sufficient. You’d need to take medicines that help support that shift.

Are thyroid problems a common issue?

It has become more of a common issue, and at Laurel Fertility Care, we see that many patients have thyroid levels of around 2.5 to 3.

Over the last five to six years, we have noticed there can be a higher risk of miscarriage for patients in that higher thyroid-level range. Organizations like the American College of Obstetricians and Gynecologists have begun to manage this more actively and have conducted research that showed that for those with a thyroid hormone between 1 and 2.4, the risk of miscarriage diminishes. That is the range that we try to keep patients within during the time they’re TTC.

We hope you found this Q&A helpful and TRB thanks Dr. Smikle at Laurel Fertility Care for his expert advice on how thyroid levels impact fertility.

If you’d like to discuss your fertility concerns further, or embark on your fertility journey, book a consultation with LFC’s wonderful team of fertility specialists here.

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