Optimizing Thyroid for Fertility
Regardless of where you are on your conception journey, getting your thyroid checked is non-negotiable.
So why is a full thyroid panel non-negotiable when trying to conceive?
THYROID BASICS
The thyroid gland is the body's metabolic workhorse.
Signals from the brain, specifically the hypothalamus, dictate how the thyroid gland functions. The hypothalamus produces thyroid releasing hormone (TRH), which signals the pituitary gland to release thyroid stimulating hormone (TSH). TSH then tells the thyroid gland to make T4 + T3, our thyroid hormones. T4 is inactive + conversion into the active hormone T3 is needed. T4 to T3 conversion happens in tissue throughout the body using deiodinase enzymes. For these enzymes + our thyroid gland to function correctly, minerals such as selenium, iron, and zinc need to be optimized. This is one of the reasons why it is vital to take a high-quality prenatal supplement with enough minerals to support your natural thyroid hormone production even before conception.
THYROID + BABY Making
The thyroid gland + its hormones are essential to our + our baby's existence.
The thyroid gland produces thyroid hormone responsible for regulating the body's metabolic rate, including heart rate, thermal regulation, muscle + digestive function, brain development, bone + skin maintenance, + so much more. A fetus is entirely dependent on the thyroid hormone of the mama for the first 24 weeks (over half of the pregnancy)! Probably the most crucial role of a mama's thyroid hormone during pregnancy is for fetal brain development. Between weeks 12 and 22 of gestation, the fetal brain develops at a fast + furious rate which means that optimal thyroid hormone from the mother is essential.
Thyroid + Fertility
Due to the extensive role thyroid plays in baby development, suboptimal thyroid function can affect fertility + overall pregnancy health.
We find that infertility is common in women with thyroid dysfunction. Hypothyroidism can lead to luteal phase dysfunction, suboptimal progesterone production after ovulation, + troubles with conception.
A meta-analysis confirmed that hypothyroidism is associated with an increased risk of "unexplained" subfertility, likely due to our thyroid hormone's role in optimizing egg + sperm quality + the fertilization process. Hypothyroidism also increases the risk of miscarriage.
Additionally, hypothyroidism in pregnancy increases the risk for placental abruption + lower IQ scores in children. Even low-level thyroid dysfunction + autoimmune hypothyroidism with "normal" TSH levels are associated with unfavorable effects during pregnancy, such as preeclampsia + pre-term birth.
Thyroid disease is prevalent in women of reproductive age. The most common thyroid disease we see is Hashimoto's Thyroiditis, an immune system attack on your thyroid gland, making it difficult to work correctly. Hashimoto's Thyroiditis is very common in women (1 out of 8), especially between the ages of 20 and 40.
So, if you are thinking about trying to conceive, have been trying for some time, or have had the unfortunate experience of a miscarriage, getting your thyroid checked is non-negotiable. Many women navigating subfertility with undiagnosed suboptimal thyroid do not have typical low thyroid symptoms. So, even if you do not feel sluggish or not experiencing other common hypothyroid symptoms such as dry skin +/or hair, hair loss, or feeling of being cold all the time, you should still get your thyroid checked. It's important to know that there is a lot of variability in how providers treat + test for thyroid dysfunction. Unfortunately, it has been my experience that many providers miss the mark when it comes to making sure you have the right amount of thyroid hormone on board to get pregnant, stay pregnant, + have a healthy baby.
FUNCTIONAL FERTILITY'S WAY TO TEST & TREAT
I can't stress this enough; it's essential to test for any thyroid dysfunction, not just overt hypothyroidism.
Ask your provider to run a complete thyroid panel with antibodies. To assess whole thyroid health, we need all the essential thyroid labs. Elevated antibodies confirm an autoimmune process in your thyroid dysfunction. It is crucial to delineate if your thyroid dysfunction has an autoimmune component because it has implications for treatment. The thyroid panel components to ask for include TSH, Free T4, Free T3, reverse T3, TPO + TG antibodies.
In my clinical practice, I recommend treatment with thyroid hormone replacement when TSH is over 2.5 mIU/L (at times, I even aim for under 2.0 mIU/L). Even if TSH is < 2 mIU/L, positive antibodies can negatively impact fertility. Positive thyroid antibodies are a sign of systemic inflammation + respond to targeting lifestyle + diet interventions. If indicated, I recommend thyroid hormone replacement with levothyroxine, a synthetic form of T4, starting with 25 mcg by mouth daily. Levothyroxine should always be taken on an empty stomach first thing in the morning 30-60 mins before food. It's essential to retest thyroid function every 4-6 weeks to evaluate if the dose of levothyroxine needs adjustment. If TSH is below 2.50 mIU/L, but Free T3 is low, your liver is not efficiently converting T4 into active T3. In this case, a functional approach to treatment is optimal + recommended.
It's vital to remember that medication can't fix an underlying autoimmune condition. Poor gut health, food sensitivities, infections, stress, + many other factors contribute to the severity of autoimmunity. When autoimmunity is a concern, take steps to address factors known to worsen autoimmune symptoms because this can drastically increase your chances of conception, a healthy pregnancy, + a healthy baby.
THYROID, PCOS + INFERTILITY: Is there a connection?
PCOS makes it 3x more likely to have Hashimoto's, yet the clear link between PCOS, thyroid health, + its implications on fertility often is overlooked.
As we know, women with PCOS make up a large proportion of women with subfertility. Unfortunately, subfertility in women with PCOS often is pinned to the PCOS diagnosis without a thorough fertility workup to rule out other contributing factors. In my opinion, this is entirely unacceptable. You deserve more; ask for more!
Especially if you have spent time addressing the root causes of your PCOS + are still struggling to conceive. It is time to work with a provider willing to stay curious + dig deeper to find other factors contributing to your subfertility, including Hashimoto's.