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Pregnancy

07th Jul 2017

How your thyroid gland may be impacting your fertility

It's something you might have overlooked.

Jessica Bourke

Unless you have previously been diagnosed with a thyroid imbalance you have probably never given a second thought to this important little endocrine gland.

Most women aren’t even aware that their thyroid function has a direct correlation with the quality of their menstrual cycle, ability to conceive and the risk of miscarriage.

So, what does the thyroid gland do?

Located in the front of the neck, the thyroid gland performs a myriad of regulatory functions to ensure that everything runs smoothly within the body. The hormones secreted by the thyroid have a direct impact on your metabolism, affecting how your body converts food into energy. Digestion isn’t the only organ system involved, your brain, heart, muscle tissue and liver are each affected by thyroid function.

By far the most common thyroid imbalance that women experience is Hypothyroidism. This is where the thyroid gland is under-functioning and inadequate levels of thyroxine, the primary thyroid hormone are being produced for circulation within the body.

There is another condition where the thyroid is over-active, known as Graves disease, but I will focus on the symptoms associated with under-active thyroid function for now, as this is more commonly seen in women dealing with fertility issues.

Symptoms of an under-active thyroid gland

It would be worth considering a comprehensive thyroid function panel if any of the following situations applies to your case;

  • You have been trying to conceive for over six months
  • Your menstrual cycle has become erratic
  • You have had two or more miscarriages
  • Your mother or other female family members have a pre-existing thyroid condition

Equally, if you have noticed two or more of the following symptoms (even if you are not actively trying to conceive), you should get tested;

  • Inexplicable, chronic fatigue
  • Cold extremities and cold body temperature (i.e. you need a jumper while those around you are happy in t-shirts
  • Dry skin or pre-mature ageing (i.e. wrinkles)
  • Thinning hair
  • Constipation
  • A slower than average heart rate
  • Stubborn weight, that won’t shift, in spite of exercise/dietary changes
  • Muscle or joint pain

How to support thyroid function

Avoid exposure to heavy metals (e.g. mercury in amalgam fillings and fluoride in drinking water.) Fluoride is important to mention because it is not removed by most standard water filters and directly competes with iodine in the body, which the thyroid uses to make the hormone, Thyroxine.

Manage stress levels: We know that raised Cortisol levels (a stress hormone) affect how the thyroid converts T4 into the active hormone T3. Exercise is helpful for stress relief and it can also help increase sensitivity of your body’s tissues to thyroid hormone.

Be careful with iodine: Granted, it’s an essential component in the production of thyroid hormone, but too much of a good thing can be bad for you, especially if your thyroid imbalance is due to an auto-immune condition known as Hashimotos Thyroidits. If you have been loading up on Kelp tablets or eating seaweed, don’t forget about Selenium. Brazil nuts are a great source but a supplement may be necessary as Selenium helps with the conversion of T4 into T3 and dietary sources may not be sufficient if you already deficient in this micro-mineral.

Dietary recommendations: Try to minimise refined grains and sugars, soy products, peanuts and stimulants such as caffeine, nicotine and alcohol.

Foods containing goitrogens may block the absorption of iodine, but this effect can be greatly reduced by lightly steaming, so you don’t have to cut out the food altogether. E.g. cabbage, broccoli, brussel sprouts, cauliflower, kale, spinach etc.

Consider a gluten-free diet. It isn’t necessary for everyone, but for those who already have gut issues and test positive for thyroid antibodies, avoiding gluten could be very beneficial.

What is involved in testing my thyroid function?

It’s just a simple blood test, but you may need to ask for a more comprehensive thyroid panel that includes more information than just your TSH (thyroid stimulating hormone) and Free (biologically active) T4 (thyroxine).

If you have a history of auto-immune disease in your family or have been suffering with chronic gut issues (e.g. IBS or IBD) than you should also request testing for thyroid antibodies. If you test positive for one or more thyroid antibodies, this is associated with Hashimotos Thyroiditis and you  should seek professional advice on a suitable diet plan to follow, alongside any medication your Doctor recommends for you.

Also watch out for the TSH result because the ideal range for fertility is between 1-2, whereas most laboratory reference ranges are much broader than that, so you may be told your TSH is ‘normal’, whereas it could be outside of the range that you need it to be at when trying to conceive.

Correcting thyroid function is unlikely to be a ‘magic cure’ for fertility problems, but it could be one part of the puzzle so it should always be properly ruled out.