• Mohamed Badaou

Your Thyroid gland and your fertility

Your thyroid gland handles a lot of functions in your body. One in eight women experiences thyroid problems in their lifetime. Thyroid problems affect the development of heart and vascular disease, your weight or even your fertility. A fast or slow thyroid also increases your risk of miscarriages and can make getting pregnant more difficult.

Thyroid problems can be easily managed with medication once detected. So it's worth knowing if your thyroid is working properly if you are experiencing unexplainable symptoms or if you are trying to get pregnant. If you want to know what effect your thyroid gland can have on your fertility and pregnancy, keep on reading!

What is the thyroid gland and why is it important?

Your thyroid gland is located at the front of your neck. It is situated just under Adam's apple. The thyroid gland is an important part of your endocrine system – the hormone-producing system of your body.

To understand this system properly, we first need to zoom out a bit. In our brain there is a thing called the pituitary gland and that is responsible for the control of various hormones, such as TSH, LH, FSH and Prolactin. The TSH produced by the pituitary gland is responsible for activating the thyroid gland. The thyroid gland then produces the hormones T3 and T4. If there’s enough of these two hormones, your thyroid gland will inhibit your pituitary gland. Thus creating its own feedback system.

These hormones can actually be seen as sisters of each other, because T4 is converted by your body into T3 when necessary. T3 then plays an important role in your metabolism. This hormone determines how much energy is released from fat and proteins. T3 also plays a role in the processing of your cholesterol and the production of insulin. A thyroid gland that is out of balance can occur in two forms:

  • Overactive thyroid, this is called hyperthyroidism Signs of this include rapid warming, weight loss, constant fatigue, rapid heart rate and sleep problems. (ref 1)

  • Underactive thyroid, this is called hypothyroidism Signs of this include dry skin, weight gain, muscle pain and being sensitive to cold. (ref 3)

Everyone can get thyroid issues, but it is known that women are up to 10x more likely to suffer from an overactive thyroid gland than men (ref 1). It is also known that approximately one in eight women develop thyroid issues during their lifetime. (ref 2).

Our body is built to maintain a delicate balance. In hyper- or hypothyroidism, we see that too much or too little T3 and T4 are made, respectively. Your body will feel this and will adjust the TSH production to get back to normal T3 and T4 levels.

Problems with your thyroid gland can often be determined by blood tests. Your blood will be checked for T3, T4, TSH or thyroid antibodies (ref 4).

Grip tests your TSH values, and if that’s out of normal range, we’d recommend you to get your T3/T4 checked by your GP.

What are possible effects of a thyroid abnormality on my fertility?

Women with hyperthyroidism often also have higher LH and estrogen production (ref 5). As a result, you can have a short luteal phase of your period, fewer ovulations and an irregular period (ref 5, 6).

Unfortunately, the mechanism of how your thyroid gland affects these hormones is not yet well understood and more research is needed on this. There is some evidence that this may be because the cells that are in your pituitary gland are able to produce not only one hormone, but several. This would mean that cells that are overactive and produce TSH can therefore also produce additional hormones such as LH and FSH (ref 7).

This all sounds scary, but don't worry. For some women, thyroid problems are much milder.

Does the thyroid gland only affect women's fertility?

No, definitely not. The fertility of men also benefits from a functioning thyroid gland. The thyroid gland plays a big role in the growth and development of your body. This also applies for the man's testes. Thyroid problems can cause all kinds of effects in men such as:

  • Reduced sperm count

  • Reduced sperm motility

  • Abnormal form of sperm (ref 6, 8)

What is the effect of a thyroid disorder on my pregnancy?

As we know, pregnancy puts a huge strain on the female body and so does the thyroid gland. During the first twelve weeks of pregnancy, the fetus does not yet have a functioning thyroid gland (ref 9). This puts additional strain on the mother's thyroid gland to produce enough for herself and the baby. Also, during pregnancy, a hormone called Beta-HCG is produced. This hormone is very similar in structure to TSH and can therefore do the same as TSH. As a result of both, as a pregnant woman, you may develop a temporary thyroid issue or if you have existing thyroid issues, that might get worse. (ref 10, 11)

Effects of a thyroid disorder on your pregnancy depend very much on what type of disorder you have:

  • Hypothyroidism is associated with a lower birth weight and problems with the development of the nervous system (ref 9). A hypothyroidism also gives a greater chance of miscarriages and premature birth. (ref 5)

  • Hyperthyroidism is often associated with growth disorders during pregnancy and preterm birth. (ref 5, 12)

These are all serious side effects and consequences of thyroid disorder. Fortunately, thyroid disorders during pregnancy are very, very unusual. On average, hyperthyroidism occurs in no more than 1% of pregnancies, a hypothyroidism occurs in up to 3% of pregnancies. (ref 12, 13)

What is the effect of a thyroid disorder on my overall health?

Your thyroid is vital in your overall health - it impacts your cardiovascular, respiratory, metabolic and renal system, etc. It is also responsible for bone growth and maturation and wakefulness. An imbalance of your thyroid hormones can affect all these systems. Symptoms includere:

  • changed alertness and wakefulness

  • hyper- or hypoventilation

  • changed blood pressure or heart rate

  • weight changes

  • brittle bones

  • Sweating too much or too little

  • digestive problems (ref 14)

What we can do for you at Grip.

At Grip we can test your TSH and thus give you an indication of your thyroid gland’s wellbeing. Although this is only one of the hormones you can test from your thyroid gland, this is the most reliable hormone we can prick. (ref 4) Also because the Grip test is an initial screening for your thyroid function, we only test TSH and not free T4. That way we can also keep the test cheaper :)

What can I do myself for a thyroid disorder?

Fortunately, a thyroid disorder is treatable. An important first step is to stop smoking, if you smoke Research has shown that smokers have an increased risk of getting hyperthyroidism. (ref 15) Women who suffer from PCOS also have a higher risk of developing hypothyroidism. (ref 16)

The treatment is also mainly aimed at normalizing the levels of your thyroid hormones. Hypothyroidism is mainly about replenishing your hormones through medication and hyperthyroidism is about lowering your hormones. If lowering your hormones is not possible with medication then there are other options such as an iodine treatment or surgery. (ref 17, 18)

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Grip tests are intended exclusively for wellness monitoring. The tests are not to be used for diagnosis or to replace a consultation with a doctor. 

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