The thyroid is a butterfly shaped hormone gland that sits at the front of the neck. It has a major role in metabolism, growth and development of the human body. The thyroid gland produces T4 and T3. An overactive thyroid gland known as Hyperthyroidism is when the thyroid gland makes too many of these hormones. An underactive thyroid gland known as Hypothyroidism is when the thyroid gland doesn’t make enough hormones.
Both of these imbalances can cause symptoms.
Some of the main symptoms of Hyperthryoid are:
Some of the main symptoms of being Hypothyroid are:
It is essential that the thyroid is working adequately in the pre-conception, pregnancy and postpartum period as thyroid disorders can lead to complications such as premature birth, high blood pressure, and miscarriage. It can also slow the baby’s growth and development.
As part of your pre-conception screening bloods, you will usually get your TSH (thyroid stimulating hormone) checked. TSH is the hormone released from the pituitary gland in the brain and simulates the thyroid to produce T3 and T4. If the TSH is abnormal then there is a problem with the production of T3 and T4 in the thyroid.
If you have a history of any problems with your thyroid, family history of thyroid disease or have experienced any miscarriages or problems with conception then you should request that you have TSH, T4 and T3 checked along with thyroid antibodies; TPO Abs (thyroperoxidase antibodies), Tg Abs thyroglobulin antibodies), TRAb (TSH receptor antibodies).
Autoimmune thyroid disease is one of the leading causes of hypo- (Hashimotos) or hyperthyroidism (Grave’s Disease). Even the presence of thyroid antibodies with normal thyroid levels can increase the risk of infertility and miscarriages.
A TSH > 2.5 mIU/L doubles the risk of miscarriage for pregnant women irrespective of thyroid antibodies (twice the risk). (Carp et al 2012)
A TSH >2.5 mIU/L & TPO Abs doubles the risk of miscarriage again (four times the risk). (Carp et al 2012)
It is important to ensure adequate iodine during preconception and pregnancy. Iodine is usually recommended during this period. It is possible to check levels by doing a urinary iodine/creatinine ratio check to ensure adequate iodine levels. Corrected urinary iodine levels should be in the range of >150 - <300 mcg/g. This test is not usually covered by Medicare.
Iodine deficiency is the most common cause of maternal hypothyroidism and it’s not uncommon. Iodine deficiency in Australia is due to poor soil content as well as declining iodine content of dairy products and low salt consumption.
Having adequate iodine stores is essential for the thyroid to adapt from a pre-conception state to its new state in pregnancy. Initially in pregnancy there is no thyroid impact from this shift because the woman will use up her iodine stores that are in her gland. However, eventually stores will start to decline as the demands from the foetus increase and uptake of iodine in the breast tissue begins to occur. Iodine plays and essential role in foetal development.
It's important to be aware that too much iodine can also cause issues with the thyroid, so it's best to seek guidance from a health professional if you’re wanting to adequately dose it.
During pregnancy the body is going through some major changes and so is the thyroid gland.
If you have been identified as having high thyroid antibodies you may benefit from taking selenium. Selenium has been found to reduce the chances of developing postpartum thyroiditis. It is thought to have an anti-inflammatory mechanism. Selenium is usually contained in most pregnancy vitamins. The typical dose is 200 mcg daily starting in 1st trimester.
Other important nutrients to support thyroid function are iron, zinc, vitamin d and b vitamins. So it please get levels checked and increase in diet or supplement if low.
Anti-inflammatory diets can be beneficial. Specifically, the removal of gluten can reduce thyroid antibody levels and therefore help to improve thyroid function.
However, it’s important to ensure that you are getting a healthy balanced diet of enough protein, vegetables and fats at each meal, as low calorie diets can also cause problems with the thyroid in itself.
Other factors that can trigger inflammation in the body and affect the thyroid include, stress, environmental toxins (such as plastics) and some cosmetics. It’s good to mindful of this and try and reduce exposure.
Often it’s difficult to differentiate thyroid disorders in the postpartum period from how most women feel “normally”. Many of the symptoms such as fatigue, hair loss, weight changes, anxiety and insomnia overlap. However, 11-22% of women will develop postpartum thyroiditis (PPT), and up to 50% women with thyroid antibodies in the 1st trimester will develop PPT.
This highlights the importance of checking for thyroid antibodies at preconception and during 1st trimester, so that these women can be monitored more closely throughout pregnancy and the postpartum period.
Your body is going through major hormonal shifts during and after pregnancy and the thyroid is vulnerable to this. The body’s need for iodine also increases and therefore it’s possible to become low in iodine, which can trigger thyroid disorders.
Postpartum thyroiditis shows up as:
For some women, symptoms can be transient and resolve within 1 year of onset, but for others, they remain in chronic hypothyroidism.
Anyone experiencing any of the above symptoms of a thyroid disorder should be checked for TSH, T4, T3 and thyroid antibodies and urinary iodine. It is also important to check for other causes of fatigue such as iron, B12 and Vitamin d deficiency.
If the TSH is higher than 2.5 or above the normal range in blood test results, it can indicate that the thyroid is becoming under active. Often there can be a delay in treatment as usually the test will be repeated 6 weeks later. However, if the patient is symptomatic, treating subclinical hypothyroidism can help to improve things. Hashimoto’s can also have an impact on cognitive function, weight, breast milk production and mood, so delaying treatment could affect milk supply and it may also affect the mother's connection with a new baby.
It can often take weeks to correct thyroid function on medication. The usual medication used is called Levothyroxine and you would start with a low dose and titrate up, monitoring blood tests every 6 weeks, until TSH and fT4 normalise. Again, there is an opportunity to come off this medication once the thyroid has been stable for some time and see how the body responds.
Dr Hazel Batten is an Integrative Doctor with over a decade of clinical experience and a keen interest in all aspects of women's health.
 Carp et al 2012
 Krysiak R, Szkróbka W, Okopień B. The Effect of Gluten-Free Diet on Thyroid Autoimmunity in Drug-Naïve Women with Hashimoto's Thyroiditis: A Pilot Study. Exp Clin Endocrinol Diabetes. 2019;127(7):417-422. doi:10.1055/a-0653-7108