A complete thyroid panel for fertility

A Complete Thyroid Panel: Your Infertility Secrets Revealed

fertility hashimoto's hypothyroidism infertility thyriod labs Nov 18, 2020

Have you ever gotten a complete and comprehensive thyroid panel? Chances are your doctor has only ordered a TSH test and nothing else. 

What bewilders me, as a fertility dietitian, is how often doctors only order that single lab test – your TSH – and miss the opportunity to take a deep dive into your health. There is much more information your body, and your thyroid, is trying to tell you. 

Perhaps your doctor has ordered a TSH test, declared it normal, and then closed the discussion on your thyroid.

“Just keep trying!"

Ugh! How frustrating is that?

You might be surprised to learn just how much your thyroid has to do with your fertility. While you may have learned about estrogen and other hormones, your thyroid hormones have an equally impressive role in your ability to conceive.


For my clients, I recommend a complete thyroid panel to fully understand their health and wellness. One lab draw can tell you an amazing amount of information about your fertility if you know what to order and how to read the results.

I recommend that you get all of the lab tests below; not only can they provide us with valuable information about your fertility, but they are also wonderful markers of your body’s overall health. It is always helpful to have a baseline. Some labs, especially the TSH, have a wide range of normal. Being able to track your personal lab history over time is helpful, too.

Let’s start with your doctor’s first instinct--testing your TSH.


What is TSH?

TSH stands for Thyroid Stimulating Hormone and the funny thing is that TSH isn’t made by your thyroid at all. TSH is made in a gland in your brain called your pituitary gland. TSH tells your thyroid to get to work, releasing more T3 and T4 hormones when your body’s cells are requesting the boost.

If demands continue to be high, your thyroid can compensate for a while, making more thyroid hormone. But if demands continue to be high for too long, or you don't have enough of the right nutrients available, eventually your thyroid will get worn out.

When your cells need more thyroid hormone than your thyroid is making, your TSH level rises to stimulate your thyroid to produce more.

It's kind of like reminding your partner to do a chore or your coworker to complete a simple task. When they slow down and don't do their jobs (like your thyroid gland), you have to remind them over and over again to get to work (like your rising TSH).

While a rising TSH tells us your thyroid isn't making enough thyroid hormone for your cells, it doesn't tell us WHY. Is your thyroid damaged and not able to produce enough? Is your thyroid making enough but your cells can't receive the hormone? Are stressors (internal or external) preventing you from converting your inactive thyroid hormone to the active form?

There are lots of questions TSH alone will never be able to answer.

For TSH, it's also important to remember that the "normal" range is quite wide. Fertility demands a tighter "optimal" range to achieve and sustain a healthy pregnancy. You also need to look at both your recent TSH value and your values over time.

To complicate things further, TSH can remain normal, even when a lot of other underlying conditions exist. That’s why it is so important to measure other lab values to get the most complete picture.


What is the Connection Between TSH and Fertility?

If your thyroid is overworked or undernourished and your TSH remains above 2.0 mU/l, your ability to conceive or keep a healthy pregnancy is decreased.

Your brain senses that you're not able to keep up with your own body, and it won't allow for another precious life to take residence. An elevated TSH can decrease your reproductive hormones as well, making pregnancy even more difficult.

Nourishing your thyroid offers you a greater chance to conceive and maintain your pregnancy.


What are Total T3 and T4?

Your thyroid makes two hormones. About 90% of the hormone it makes is T4 (thyroxine) and the remaining ~10% is T3 (triiodothyronine). Measuring your TSH – the first hormone we talked about – lets us know how much your thyroid is being signaled to produce and release T3 and T4. Measuring the Total T3 and T4 lets us know how well your thyroid is able to respond with the right amount of hormones. 

Your thyroid hormones talk to every cell in your body and are factors in everything from your temperature, mood, hair loss, bone health, digestion, and metabolism. And of course, fertility.


What is the Connection Between T3/T4 and Fertility?

If your T3 and T4 hormones are not in the optimal range – which is more narrow than the lab’s “normal” range – you are going to have a harder time getting and staying pregnant.


One study looked specifically at women who were undergoing IUI (intrauterine insemination) and found that there was a significant difference between women who were able to conceive and those who weren’t, as evidenced by their T3 and T4 levels (1). If your levels are out of range, the chances of the procedure being successful are a lot less.

Most often, T3/T4 levels are too low, especially in women struggling to get pregnant. Some of the most common signs of low thyroid hormone and function are:

  • low basal body temperature (consistently below 97.5ºF / 36.4ºC)
  • delayed or no ovulation
  • menstrual cycles shorter than 21 days or longer than 35 days
  • very short or light periods
  • heavy or prolonged menstrual bleeding
  • short luteal phase or signs of low progesterone
  • irregular cervical mucus patterns

For successful conception and pregnancy, it's imperative that your thyroid hormones are in a healthy, optimal range. That is exactly what I help my clients to do.

Plus, optimizing your hormone levels also improves your outcomes with fertility treatments, including IUI and IVF. So, these lab values can provide you with valuable information no matter where you are on your journey. 


What are Free T3 and T4?

While the TOTAL amount of hormone your thyroid gland makes is important, much of your Total T3 and T4 remains bound to proteins and not available for your cells to use.

Measuring your FREE T3 and T4 shows you how much of that total is unbound (free) and available to your cells (2). Because Total T3 and T4 are dependent on your protein status, Free T3 and T4 are considered to be more valuable data (3).


What is the Connection Between Free T3/T4 and Fertility?

If your body is making T3 and T4 but they are not actually available for your body to use, your fertility is going to be impacted.

Low Free T3 and T4 can cause:

  • low egg quality
  • low ovarian reserve
  • premature ovarian insufficiency
  • unsuccessful IUI and IVF
  • higher rates of miscarriage
  • overall decreased fertility

In addition to checking your Total numbers, you need to check your Free T3 and T4 so you know exactly what your cells, especially those of your reproductive system, have available.


What is Reverse T3?

As we discussed, T3 is the active, usable form of thyroid hormone. Factors like unmanaged stress, inflammation, and infection can deactivate T3 into Reverse T3. If T3 is the accelerator that your cells need, Reverse T3 is the brake.

When your body is continually stressed (internally or externally), she does what she can to conserve energy to protect you.

Increased levels of Reverse T3 indicate that your body is "putting the brakes" on your active T3 so you don't burn yourself out. This deprives your cells of the energy they need, especially the great deal of fuel needed for reproduction.

While it's less common to test, Reverse T3 can give good insight into why your thyroid hormones aren't as optimal as they should be...and why your fertility could still be suffering.


What is the Connection Between Reverse T3 and Fertility?

Your body wants to be able to conceive a healthy pregnancy. If your body senses that the environment is too stressful or resources are too scarce, reproduction does not become a priority. Reverse T3 can provide insight into how much stress your body is under and give us reason to look deeper to what those stressors are.


What are TPO and TG Antibodies?

Your immune system is a highly intelligent system designed to protect you from foreign invaders like bacteria, viruses, and other pathogens. It destroys these invaders with substances called antibodies that are made by your white blood cells.

If you have a thyroid disorder, it's not uncommon for that dysfunction to be caused by your immune system attacking your thyroid gland itself. This is called thyroid autoimmunity.

Your immune system makes antibodies against your own thyroid cell proteins, and this attack damages and destroys your thyroid tissue. As you might imagine, this decreases thyroid function, deprives your cells of the hormones they need, and your fertility suffers.

The two most common are Thyroid Peroxidase (TPO) and Thyroglobulin (TG) antibodies. Measuring your TPO and TG antibody levels can help diagnose the cause of your thyroid problem.

For example, elevated levels of anti-TPO and/or anti-TG antibodies, along with decreased thyroid function, can result in a diagnosis of Hashimoto’s thyroiditis.

Incredibly, your thyroid gland can be under attack for up to 10 years before you show overt thyroid symptoms or your labs pick up on it. Checking your antibody levels now lets us know what is lying beneath the surface.


What is the Connection Between Thyroid Antibodies and Fertility?

If your thyroid perceives that your body is overly stressed or under attack, it won't prioritize your menstrual cycle and certainly not reproduction. A new potential life is at high risk when your body is attacking her own tissue.

Elevated anti-TPO antibodies is a significant cause of multiple miscarriages.



What Can You do to Support Thyroid Health?

You can definitely support your thyroid function by eating a wide variety of colorful, unprocessed foods. These whole foods provide essential nutrients for your thyroid like protein, zinc, selenium, iron, iodine, vitamins A and D, B vitamins, and magnesium.

Making sure you consume enough total calories is important for thyroid health as well. Adhering to low-calorie or low-fat diets for extended periods of time can decrease thyroid function and increase your symptoms. If you've noticed new or continued symptoms related to low thyroid function, you might want to investigate whether you need to add more overall nourishment to your intake.

Eliminating toxins that harm your thyroid is just as important as including thyroid-supporting nutrients.

Toxins like xenoestrogens, heavy metals, and pesticides can impair female and male fertility alike. Excess toxins or your inability to clear them can also increase inflammation, suppress your immune system, and lead to autoimmune conditions like Hashimoto's.


Key Takeaways

As you can see, your body has a lot of information available if you know where to look and what to measure.

  • Optimal thyroid health is essential for a healthy pregnancy.
  • A full thyroid panel is essential for knowing exactly how your thyroid is functioning. 
  • Go beyond just testing TSH and include Total T3 and T4, Free T3 and T4, Reverse T3, TPO and TG antibodies to truly know how your thyroid status is affecting your fertility.
  • Nourishing foods and a healthy environment are vital to thyroid function.
  • Ensure that you're nourishing your thyroid with enough protein, zinc, selenium, and other nutrients that it needs.
  • Avoid toxins that impair your thyroid and fertility.


If you're ready to take a deep dive into your hormonal health so you can know exactly what to do to optimize your body’s readiness to conceive, let’s connect! You can set up a FREE 30-minute strategy session HERE. You'll discover the exact next steps you need to take to start nourishing your thyroid and all your hormones today!


In joy and health,


This information is not intended to be personal medical advice. Never start a supplement, change a medication, or make any other modifications to your health regimen without first consulting with your physician or appropriate health practitioner.

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