Thyroid and Fertility (part 3 of 3)
This is a test.
Now we’ve talked about symptoms that may indicate your thyroid needs some support, labs to ask for to assess thyroid function, and some foundational ways to support your thyroid (read Part 1 and Part 2). Now it’s time to chat about the most common thyroid issue: hypothyroidism
What is hypothyroidism?
Hypothyroidism is a condition in which the thyroid gland is considered ‘underactive’, meaning it does not produce enough thyroid hormone for the body.
How common is hypothyroidism?
Hypothyroidism impact about 5% of the population with the estimated 5% going undiagnosed. Hypothyroidism is more common in women vs. men.
What causes hypothyroidism?
Worldwide, the most common cause is iodine deficiency. In the US, which is considered iodine sufficient (but many people still fall short), Hashimoto’s thyroiditis (an autoimmune condition in which the body attacks the thyroid) is the most common cause of thyroid failure and hypothyroidism.
What are the symptoms of hypothyroidism?
Nearly every cell in the body uses thyroid hormone so when there’s not enough, symptoms can show up across the board. They include:
- fatigue
- brain fog
- dry skin
- irregular cycles
- heavy periods
- infertility/pregnancy loss
- hair loss
- elevated blood lipids
- constantly feeling cold
- stubborn weight loss
- unintentional weight gain
- among many more
How is hypothyroidism diagnosed?
Hypothyroidism can be diagnosed by your physician via a blood test measuring thyroid hormone levels. The most common thyroid lab test measures TSH (thyroid-stimulating hormone) but that doesn’t give you a full picture of thyroid function. I recommend clients get a full thyroid panel (TSH, total and free T3, total and free T4, reverse T3, and thyroid antibodies). That’s the only way to truly assess the functioning of the thyroid as a whole. Hashimoto’s is typically diagnosed by the presence of thyroid antibodies (which is why it’s important to have those measured!)
When being “diagnosed” with hypothyroidism, it should be noted that there’s a scale or range of diagnosis. You could be diagnosed with overt hypothyroidism (usually when TSH is high and major thyroid hormones are low). Or you could also be diagnosed with subclinical hypothyroidism (one example being when TSH is high but other major thyroid hormones are normal).
How does hypothyroidism impact fertility?
Your menstrual cycle relies on thyroid hormone for a number of reasons so when there isn’t enough thyroid hormone available, interruptions in your cycle can occur. That includes: reduced or extended time between cycles, anovulatory cycles (when you don’t ovulate), and heavy periods, among other symptoms. It can lead to what’s called subfertility meaning you still have the physical ability to get pregnant but there are obstacles in the way.
With thyroid autoimmunity (for example Hashimoto’s thyroiditis), it can make it more difficult to get pregnant by reducing thyroid function when the ovaries require thyroid hormone to recruit and mature follicles to ovulate. Having the presence of thyroid antibodies can reduce the number of follicles and lead to low ovarian reserve.
How does hypothyroidism impact pregnancy?
If untreated, hypothyroidism can pose a number of risks during pregnancy including: developing gestational hypertension or preeclampsia, placenta abruption, miscarriage, preterm delivery, or stillbirth. If treated but not adequately, there’s a risk of intrauterine growth restriction (IUGR) and/or low birth weight, and delays in neurological development.
With subclinical hypothyroidism, there is an increased risk of miscarriage and preterm delivery.
How is hypothyroidism treated?
With overt hypothyroidism, a medication consisting of synthetic T4 most likely will be prescribed to help provide the body with sufficient amounts of thyroid hormone. Sometimes desiccated thyroid that contains T4 and T3 hormone can be prescribed. With subclinical hypothyroidism, it depends on a number of factors including if you’re positive for thyroid antibodies, how high are TSH levels, and how total and free T3 and T4 look. It’s usually on an individual basis and also dependent on your doctor’s philosophy of a) whether subclinical hypothyroidism is a thing and b) if they think it needs to be treated or not.
In both cases of overt and subclinical hypothyroidism, it’s also helpful to continue doing the foundational habits to support your thyroid (read about that in this blog post), as well as some additional supportive habits.
What else can I do to support my thyroid?
Here are some more advanced ways to support your thyroid:
- eating enough throughout the entire day
- eating adequate amounts of protein (including seafood multiple times per week!)
- reducing exposure to endocrine disruptors
- consuming thyroid supporting vitamins and minerals
- getting good quality and adequate amounts of sleep
- effectively managing stress
- supporting digestion and absorption
Your thyroid plays a significant role in your fertility and future pregnancies (issues can also arise during postpartum but that’s for another blog post!) It’s worth it to provide your thyroid with what it needs to function properly!
If you find yourself struggling to get pregnant and suspect it might be your thyroid, reach out for help and support! I’m accepting new clients and you can apply to work with me here.
Thyroid and Fertility 101 (part 1)
January is Thyroid Awareness Month.
But actually, it feels like that every month over here in my little corner of the internet because I so heavily emphasize getting it checked with nearly all of my clients.
It’s because the health of your thyroid plays a significant role in your ability to get pregnant and your ability to sustain a pregnancy.
Your thyroid is a butterfly-shaped gland located in front of your throat and releases thyroid hormones that serves various functions throughout the body.
Nearly every single cell uses thyroid hormone to help with metabolism (processing nutrients and energy). Your thyroid can also be described as the thermostat of the body due to its role in controlling your temp.
Your thyroid is involved in:
temperature regulation
heart rate
nutrient metabolism
brain function
menstrual cycles
growth and development (for you always and for your baby while pregnant)
…among many more roles!
I’ll be focusing on the roles your thyroid plays in menstrual cycles and pregnancy and what can happen when there are disruption in thyroid function.
But before we get into that, I’ll go over how the thyroid works (important to discuss how it works under normal circumstances so you better understand what’s going on when it’s not working properly).
How the thyroid works
Your brain and thyroid communicate via the HPT axis or hypothalamus-pituitary-thyroid axis). The hypothalamus released TRH (thyrotropin-releasing hormone) that stimulates the pituitary gland.
The pituitary gland then releases TSH (thyroid-stimulating hormone) that stimulates the thyroid to release T3 (20%) and T4 (80%) (and calcitonin but we’re skipping over that part). T3 is much more potent than T4 and is considered the active form of thyroid hormone.
T3 and T4 then travel throughout the body assisting cells in regulating their metabolism (among the many other roles listed above). Cells can also convert T4 to T3 or reverse T3 (the inactive form of thyroid hormone) depending on needs.
When concentrations of T3 and T4 in your bloodstream reach a certain level or threshold, they create a negative feedback loop to your brain. This shuts off the release of TRH, which then shuts down the release of TSH, decreasing the stimulation of your thyroid. Normal stimulation resumes again once T3 and T4 levels decrease.
This is a “picture perfect” version of how your thyroid (should) function. Of course, things don’t always work out that way!
Thyroid’s role in menstrual cycles
The thyroid’s role in menstrual cycles is complex…to say the least. I’ve tried to simplify it here but know this is surface level. It goes much deeper than this and there’s still so much we don’t know.
Thyroid hormone plays a role in how sex hormones are made, transported, and excreted. By sex hormones we’re talking major players like estradiol and testosterone.
Thyroid hormone also plays a role in controlling other hormones that indirectly influence your cycle. So, thyroid hormone can influence factors such as the length between periods (whether short or long or if your period shows up at all) to how light or heavy your period flow is.
Thyroid hormones also act directly on ovarian cells. One role is to help facilitate the recruitment and maturation of follicles (very important as those are the beginning stages of ovulation).
So, when there are disruptions in thyroid function, it can have several downstream impacts on your cycle, which can ultimately impair your fertility.
That’s where taking care of your thyroid is SO important when it comes to preconception health and at the core of what I look into with clients who are struggling to get pregnant.
Thyroid’s role in pregnancy
There is an increased demand for thyroid hormone during pregnancy.
In the early weeks of pregnancy (up to week 12), the fetus is dependent on your thyroid’s ability to provide it necessary hormones.
By week 12, the fetus is starting to make its own thyroid hormones but still not enough until about weeks 18-20 (meaning still heavily dependent on you).
Most importantly, the fetus needs thyroid hormone to have proper brain and nervous system development. (Remember above when I mentioned that every cell in the body uses thyroid hormone to function).
Your thyroid needs to be able to not only provide you enough hormone but the fetus, too (and have that amount of hormone be enough but not too much!
Bottom line: the function of your thyroid is crucial to sustaining a healthy pregnancy!
This month we’ll be getting into the ways to support your thyroid and what labs to ask for to assess function!
If you’re wanting support for your thyroid while TTC, apply to work with me here!