

Pregnancy and your thyroid
The thyroid gland sits above the larynx, it’s two little lobes giving it the appearance of a small butterfly. This seemingly small body part governs everything from your emotions to your weight but unfortunately it has some challenges particularly during pregnancy.
I often hear from clients that they have had everything tested by their doctor and, although they feel fatigue, sluggishness, and low motivation bordering on depression, according to their blood tests they are apparently in perfect health! Wonderful! Except you still feel sick. One of the things I always want to rule out in these situations is an underperforming or overactive thyroid gland.
Our thyroid gland punches above it’s weight as far as it’s responsibilities in the body. It has wide ranging effects and is intimately connected with our reproductive and nervous systems as well our metabolisms. The gland releases two types of thyroid hormones called triiodothyronine (T3) and thyroxine (T4). T3 is the active hormone and is converted from T4.
Some of the important functions of T3 include:
Brain development
Metabolism
Body temperature
Muscle strength
Menstrual cycles
Libido
Fertility
Skin dryness
Hair thickness
Cholesterol levels
Production of thyroid hormone is regulated by thyroid stimulating hormone (TSH) which is released by the pituitary gland in the brain. When blood levels of thyroid hormone drop, the pituitary releases more TSH. When levels of thyroid hormone are high it responds by releasing less TSH. In this way the perfect balance of thyroid hormone flows through the blood stream activating it’s target cells and maintaining a healthy equilibrium.
A healthy thyroid is crucial for a healthy pregnancy
Your thyroid gland is important for your health during pregnancy but it also plays a critical role in the normal brain and nervous system development of baby. From conception until 12 weeks baby depends on your thyroid hormone (via the placenta) then at 12 weeks it begins to make it’s own as it’s thyroid begins to develop.
Pregnancy’s effect on your Thyroid
During all pregnancies the thyroid gland experiences some changes that are completely normal. The pregnancy hormone human chorionic gonadotropin (hCG) is similar to TSH so has a mildly stimulating effect, leading to increased production of thyroid hormone. The increased oestrogen during pregnancy leads to higher levels of thyroid binding globulin which means more thyroid hormone can be carried in the blood. Both of these changes are normal and usually don’t cause any problems during pregnancy.
Thyroid problems in pregnancy
If a person is for some reason vulnerable to thyroid problems, they may find that pregnancy is their trigger. That vulnerability may be due to family history, iodine deficiency, previously undiagnosed thyroid imbalance, or high stress during pregnancy. The two most common issues to arise are overactive thyroid (Graves disease) and underactive thyroid (Hashimoto’s).
Graves disease
Graves disease is an autoimmune condition and occurs in 1 in every 500 pregnancies. Your normally protective immune system begins to attack the cells of your thyroid. For some reason your immune system makes an antibody called thyroid stimulating immunoglobulin (TSI) which mimics TSH and causes extra release of thyroid stimulating hormone. This, in turn leads to too much release of thyroid hormone and the ensuing problems can include:
Rapid heartbeat and palpitations
Fatigue (pretty common in pregnancy anyway!)
Heat intolerance
Anxiety
Diarrhoea
Weight loss (unusual in pregnancy)
Enlarged thyroid which bulges or causes discomfort swallowing
Eye irritation such as puffiness, itchiness and bulging.
Untreated Graves disease can lead to more severe problems such as miscarriage, congestive heart failure, preterm labour, low birth weight and preeclampsia (dangerous high blood pressure).
Graves disease is diagnosed by blood tests such as TSH, T3, T4, thyroid antibodies and reverse T4. Although thyroid problems can be quite tricky to diagnose in pregnancy due to the abnormalities that occur even in a healthy woman. It’s also very common to experience fatigue, palpitations or heat intolerance in a healthy pregnancy so many doctors are reluctant to put you through extra testing. With the possibility of negative outcomes in mind though, don’t hesitate to speak to your lead maternity carer if you have any of the above symptoms or you notice a larger than normal thyroid gland. Tick that box and put your mind at rest.
How is Graves disease treated in pregnancy?
If the hyper action of the thyroid is mild, often there is no treatment at all, but careful monitoring throughout the pregnancy to make sure it doesn’t worsen. In severe cases you will be treated with anti-thyroid medication which works by interfering with the production of thyroid hormone. The right dose for each women needs to be settled on, in order to gain a healthy balance and not push her into an underactive situation. Also, the lowest possible dose is sought due to the medication crossing the placenta and effecting foetal thyroid hormone production, which can in turn lead to hypothyroidism in the baby. In extreme cases part or all of the thyroid gland may be removed.
Natural support for Graves disease
A combination of approaches always works best in my opinion. A woman may need anti-thyroid medication to get the symptoms under control and then natural medicine can be utilised as a longer term plan. Keeping those thyroid hormones in balance during pregnancy should be the main goal to achieve a healthy pregnancy and the best outcome for baby.
Melissa officinalis – this lovely stress relieving herb has shown beneficial effects in reducing the symptoms of hyperthyroid and is very safe. It has been shown to inhibit TSH from attaching to TSH receptors, thereby reducing thyroid hormone in the body.
Lycopus virginicus – is an herb native to North America and has been used in hyperthyroid disease and Graves disease by herbalists for many years. It seems especially helpful for the rapid heartbeat, bulging eyes and shortness of breath experienced in Graves disease.
Leonurus cardiaca – also called motherwort this is a wonderful herb for the palpitations of hyperthyroid and has a long history of use during pregnancy as a uterine tonic.
This herbal combination can be mixed by a qualified medical herbalist.
Iodine should be used with caution in autoimmune thyroid conditions. The thyroid uses iodine to make thyroid hormone therefore too much can lead to an exacerbation of hyperthyroid symptoms. The Royal Australian and New Zealand College of Obstetricians and Gynaecologists as well as the Ministry of Health in NZ recommends the routine prescribing of iodine along with folic acid prior to, and during pregnancy. This is due to widespread deficiency of iodine. Unfortunately, this isn’t helpful for some women and reminds us of the uniqueness of each pregnancy and every woman’s need for healthcare specific to them.
Adding foods that inhibits the uptake of iodine (goitrogens) can also be helpful: Broccoli, cauliflower, cabbage, kale, almonds, peanuts, Brussel sprouts.
Stress reduction is very important in a hyperthyroid condition. All the usuals such as yoga, tai chi, meditation, and diaphragmatic breathing will help. An overwrought, exhausted or anxious nervous system will do your frantic thyroid no favours. In fact, stress depletes natural killer cells which normally prevent the development of autoimmune disorders.
Did I mention to avoid caffeine and reduce sugar? Goes without saying really!
Hashimoto’s Disease
The second most common thyroid condition arising in pregnancy is an underactive thyroid usually caused by Hashimoto’s disease. This condition is also an autoimmune disorder and is a form of chronic inflammation of the thyroid gland. The immune system directly attacks the thyroid gland leading to difficulty producing adequate amounts of thyroid hormone. It doesn’t take long for this lack of thyroid hormone to wreck havoc in the following ways:
Extreme fatigue
Cold intolerance
Constipation
Thinning hair
Bilateral carpal tunnel
Weight gain
Dry skin
Slow heart rate
Facial puffiness
Poor concentration and memory loss
Anaemia
When left untreated more extreme symptoms occur such as problems with foetal growth and brain development, miscarriage, preeclampsia, low birth weight, and heartbreaking still birth.
Hashimoto’s is diagnosed in the same way as Graves disease. Your health professional will be looking for high TSH and low thyroid hormone. Be sure to prompt them to also check your thyroid antibodies. These are most important, and often not done.
How is Hashimoto’s disease treated during pregnancy?
The treatment is actually the same for an underactive thyroid whether you are pregnant or not. With a synthetically produced form of thyroxine (thyroid hormone). If a woman was already being treated for hypothyroidism she may need to increase her dose to counter the natural changes that occur in all pregnancies. Monitoring is recommended every 6-8 weeks to ensure any changes are picked up and the dose of the drug changed if necessary.
It’s important to know that an underactive thyroid is very common without actually having Hashimoto’s disease. A great many women suffer from undiagnosed subclinical hypothyroid function which can worsen in pregnancy. This is different to Hashimoto’s as it’s not autoimmune in origin, although it can have the same effects.
Natural support for underactive thyroid in pregnancy (Hashimoto’s and non autoimmune hypothyroid)
My main focus for patients with an underactive thyroid is to provide the thyroid gland with as much of the raw materials it needs to make more thyroid hormone. The other important goal is to reduce inflammation so it can get back to balanced function.
Withania somnifera – this herb has great thyroid stimulating properties. It’s been shown to increase the production of T4 by an amazing 111%. It increases conversion of T4 to the active T3. Withania is also a wonderful stress relieving herb.
Lycium barbarum – you probably know this herb as goji berry. As well as being great decoration for your raw desserts, goji is renowned for restoring the antioxidant processes involving superoxide dismutase and glutathione peroxidase. These two processes are crucial for reducing the inflammation of hypothyroid conditions.
Iodine deficiency is a leading cause of hypothyroid function around the world. In New Zealand and Australia its estimated that 80% of the population doesn’t meet their RDI of iodine. Our soils have become very low in this once abundant mineral. Iodine supplementation is very important to increase thyroid hormone production. The standard pre pregnancy prescription (government funded) is 250 micrograms, but you may suit more. Using iodised salt is also recommended. And it’s important to combine supplemental iodine with the next mineral I talk about.
Another mineral that is low in our soils in this part of the world is selenium. We are said to get even less than the very conservative RDI of 70mcg per day in NZ and Australia. Selenium and and also zinc are crucial for the conversion of the less potent T4 to the active thyroid hormone T3. Selenium has also been shown to reduce the level of antibodies in Hashimoto’s disease by 36% over 3 months (taking 200 micrograms daily).
Reducing foods that inhibit iodine absorption such as broccoli, cauliflower, cabbage, kale and soy is also important. It doesn’t mean you should never eat them, but limiting to ½ cup every few days will help. Also cooking reduces the so called ‘goitrogenic’ effect of these foods. If you don’t have an underactive thyroid these foods wont decrease thyroid function and are of course wonderfully healthy.
So as you can see your little butterfly gland plays a crucial role in the health of you and your baby in pregnancy. Don’t ignore symptoms or put them down to ‘just being pregnant’. Being pregnant is not a disease! You should feel well in pregnancy, albeit a little uncomfortable in your clothes or more easily pooped by the end of the day. If you’re concerned at all, don’t hesitate to talk to your healthcare provider, they are there to help you!
Annaliese Jones has been helping people for over 10 years with their health, holistically. She practices nutrition, naturopathy and herbal medicine in her Auckland clinic. www.annaliese.healthcare