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Is An Underactive Thyroid Preventing You Getting Pregnant?

This series of articles is looking at fertility and how naturopathic medicine can help improve it if you are having difficulty conceiving. This time, I want to look at the role the thyroid gland can play in infertility. If you have missed any of the previous articles in this series and would like to catch up you can find them here:

The primary function of the thyroid gland is to produce hormones to regulate your metabolism, however it also plays an important role in female and male fertility and pregnancy by:

When thyroid hormone levels are too high or too low the following pregnancy risks can occur:

A malfunctioning thyroid gland can either be underactive (hypothyroid) or overactive (hyperthyroid). Of the two, hypothyroid can be harder to diagnose and the signs and symptoms can be more subtle and less obvious than those related to hyperthyroid; because of this hyperthyroid symptoms are less often overlooked. For this reason, in this article I will focus on the underactive hypothyroid condition; however, I will review hyperthyroid symptoms for comparison.

The Thyroid and Fertility

The thyroid plays a pivotal role in fertility for both men and women but, since thyroid conditions are more common in women than men, fertility issues resulting from a thyroid imbalance are also more common in women. In fact, many people who struggle with infertility go undiagnosed with hypothyroid.

The thyroid gland is part of the endocrine system and, along with the ovaries and adrenal glands, its job is to control the hormones in our body. These hormones are responsible for communication between the brain and our organs and tissues. The thyroid gland produces thyroid hormone whose primary role is energy metabolism. It also regulates weight, memory, focus and temperature. In addition to the above metabolic functions, thyroid hormone also has an influence on the reproductive system and plays a role in fertility and the health of the developing baby.

In males, too much thyroid hormone (an overactive thyroid) affects testosterone levels, causes low sperm count and low motility of sperm – not enough healthy, strong swimmers will decrease fertility.  In males with hypothyroid, testosterone levels, semen quality and volume are reduced and sperm morphology, quality and motility are decreased. To read more about healthy sperm you can refer to the article, Wanting To Get Pregnant? Don’t Forget About Sperm Health.

In women with an overactive thyroid, the main risk is with the developing fetus. There is poor fetal development and, because of that, an increased risk of miscarriage and premature birth.

For women with hypothyroid, a decrease in body temperature affects ovulation and the quality of the uterine lining which is needed for a fertilized egg to attach to (implantation) – 2 key factors in infertility. Thyroid hormone is also essential for cells to properly divide, crucial for rapidly dividing fetal cells. Basically, if we do not have enough thyroid hormone the developing fetus inside the uterus will not grow properly and there is an increased risk of miscarriage.

How Can I Tell if I have a Thyroid Imbalance?

If you have been struggling to conceive and physicians are unable to give you a satisfactory reason why this is, it might be worth looking to your thyroid to see if that is the cause of your unexplained infertility. Many people walk around for years with an underactive thyroid and don’t even know it so the first thing to do is look at the following list of signs and symptoms that may be caused by thyroid problems to see whether you are experiencing any of them before going to your doctor and asking to be tested:

Signs of an Underactive or Overactive Thyroid

Signs of an Underactive Thyroid

Signs of an Overactive Thyroid

Testing – How Can I Be Sure My Thyroid Is Functioning Optimally?

If you are feeling frustrated that you have not been able to get pregnant or if you have talked to your doctor or fertility specialist and still been given no answers to why you cannot conceive then, your fertility struggles could be caused by hypothyroid. In fact, even if you’ve been told numerous times that your thyroid is fine you could still have an underactive thyroid. Let me explain.

It all comes down to the training of your physician.

Progressive-thinking physicians have been trained to read the whole picture of the person, all their symptoms, their basal body temperature and their thyroid labs. When your physician takes all of these variables into account then you may find an underactive thyroid gland as the cause of your infertility. Unfortunately many practitioners only look at a single lab value – TSH (thyroid stimulating hormone) – before making a decision about your endocrine system. This is why the diagnosis of hypothyroid gets overlooked for so many people.

If you are preparing for pregnancy or struggling with infertility it is important to understand what type of thyroid testing you should have done. Here is a complete list of thyroid lab testing I do on all of my patients, not just for fertility purposes, and the ranges that indicate that your thyroid is functioning normally. You may find your physician hesitant to run all of these labs and therefore you will need to find a physician who is familiar with, and willing to run, them all:

The problem with using TSH as the only screening or monitoring tool for an underactive thyroid is that different physicians read the range differently. As a Naturopathic physician I was always told that a TSH of 2 or under, with symptoms of low thyroid, should be treated as hypothyroid. However as you can see above, the normal range on labs is 0.450-4.5 uIU/ ml so, if someone had a TSH of 2.5 or 3 they may be told their thyroid is normal when in fact they are hypothyroid.

Free T3 and Free T4 have tight parameters and are a good gauge of circulating levels of thyroid hormone. Reverse T3 reflects the ability to convert T4 into active T3 so, if reverse T3 is high then you may not have enough active thyroid hormone.

Autoantibodies should either be not present at all or in very low in the case of anti-thyroid peroxidase antibodies. If they are present in high amounts but TSH, Free T3 & Free T4 are all within normal limits then you should monitor your thyroid labs yearly.

In addition to labs testing, basal body temperature (BBT) can be used to assess thyroid hormone function. This is based on Wilson’s Thyroid Protocol, developed by Dr Wilson M.D.  In Wilson’s Thyroid Protocol you do not use blood levels to determine if your thyroid is under functioning or hypothyroid, you take your BBT 3 times a day and, if the average of those three readings is below 98.6 F then you likely have an underactive thyroid. Wilson’s Thyroid Treatment Protocol uses the active form of thyroid hormone T3 to reset the thyroid gland and should be done under the care of a trained Wilson Thyroid specialist.

I Suspect I have a Thyroid Condition – What Can I Do?

When diagnosed with hypothyroid, most people start taking prescription thyroid hormones. There are few pharmaceutical options:

Many people with borderline thyroid lab results are however, hesitant to start thyroid hormone and want to know what they can do before starting pharmaceutical replacement. The following is a list of the nutrients used to support the thyroid gland and help with thyroid hormone production. Before starting any treatment, I recommend you check with your physician to determine the best course of treatment for you:

In Summary

If you are thinking about getting pregnant or have been trying to conceive with no success and you have any of the thyroid signs and symptoms listed above then I recommend you ask your physician to do a thorough thyroid evaluation. Increasing your fertility could be as simple as adding thyroid hormone or even adding vitamins and minerals to support your thyroid hormone.

In my years of practice I have seen many women struggling with fertility who managed to conceive shortly after beginning thyroid hormone and some of these women did not even need to stay on the thyroid hormone after they delivered their baby. I have changed many people’s lives by diagnosing and treating their underlying hypothyroid condition.

Over and over again I hear people wondering why their hypothyroid condition wasn’t diagnosed earlier by another physician. Many people know there is something off with their body but they are not able to figure out what it is. So if you have been struggling with infertility please make sure your thyroid is working properly.

If you would like to have your thyroid tested or would like to work with me on your fertility, find out more information about my fertility package.

Join me next time when we will explore the role of adrenal stress in infertility.

Dr. Maura Scanlan

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