7 key times when a woman may need her thyroid tested...

  1. if you're struggling to conceive

  2. if you are diagnosed with PCOS

  3. pregnancy - especially if there is a family history of thyroid problems

  4. after childbirth - if you feel unwell or develop anxiety or depression

  5. after miscarriage

  6. perimenopause - as thyroid hormones sometimes drop at this time together with reproductive hormones

  7. after severe emotional stress or shock

1. thyroid health affects fertility

In recent years much more attention is being paid to thyroid health and how it affects fertility.

  • for optimal fertility we prefer the Thyroid Stimulating Hormone (TSH) to be below 2

  • most IVF clinics now routinely test for thyroid function and some give thyroid treatment support during the IVF cycle to improve chances of success

  • if you’re struggling to conceive ask your GP for thyroid function tests, especially if there is any family history of thyroid problems

2. pcos increases the likelihood of thyroid problems

This relationship works both ways round

  • women with PCOS are more likely to develop thyroid problems

  • women with thyroid problems may have more insulin resistance which can worsen PCOS

  • hypothyroid disease can cause changes in the ovaries - they can become enlarged and develop cysts - which may be misdiagnosed as PCOS

3. pregnancy increases the demand on your thyroid

  • during pregnancy we prefer the TSH to be below 2.5

  • It may also be wise to have additional tests of T4 and T3 done in the first trimester.  This is because TSH levels are less reliable in early pregnancy - they are lower because they are suppressed by the rising levels of the pregnancy hormone HCG.   From about 16 weeks of pregnancy TSH levels become a more reliable indicator again (Lazarus, 2010)

4. low thyroid may look like post natal depression

  • hypothyroid disease may be triggered by the physical stress of pregnancy and cause depression which may be misdiagnosed as post-natal depression

5. thyroid problems can increase risk of miscarriage or preterm delivery

When investigating for miscarriage both TSH and thyroid antibodies should be tested.

Higher miscarriage rates have been observed when TSH is above 2.5 in the first trimester.

  • thyroid antibody negative women had a 2.5% higher rate of pregnancy loss when TSH was 2.5 or above

    this study recommends that 2.5 should be the upper limit in the first trimester (Negro et al. 2010)

If you experience miscarriage then it is worth getting tested for thyroid antibodies, 2 types are usually tested - thyroid peroxidase antibodies and thyroglobulin antibodies.

  • If you are antibody positive then thyroid treatment during pregnancy may reduce your miscarriage risk even if your thyroid hormone levels are normal (Lepoutre et al. 2012) (Negro et al. 2006)

  • thyroid peroxidase antibody positive women with normal TSH showed an increased rate of preterm delivery (Negro et al. 2011)

The good news is that miscarriage risk and preterm birth may be reduced by supporting the thyroid with thyroxine

  • a meta-analysis of 13 studies confirms that treatment with thyroxine reduces risk of miscarriage and preterm birth (Rao et al. 2019)

  • an earlier review showed increased live birth rate with thyroxine treatment for women undoing IVF who had subclinical thyroid problems or positive antibodies (Velkeniers et al. 2013)  

6. thyroid levels may drop in perimenopause

Thyroid hormone levels may begin to drop as oestrogen levels drop. Symptoms of hypothyroid and perimenopause are very similar - mood changes, fatigue, weight gain, sleep problems - so it is important that a thyroid diagnosis isn’t missed.

7. grief, shock and emotional trauma can upset thyroid balance

The thyroid is a sensitive gland and any physical or emotional stress can upset it’s balance or increase it’s needs. Pregnancy, accident, illness or emotional shock can trigger thyroid problem especially if you have a family history.

blood tests for thyroid

Your GP will routinely measure TSH but may not do other thyroid blood tests.  TSH is regarded as the most sensitive test of thyroid health though it doesn't give a complete picture.  Other tests can be arranged privately.

  • TSH normal reference range is around 0.4 - 4.5

  • TSH below 2 is optimal for fertility, and below 2.5 during pregnancy

If you chose to be tested privately a Full Thyroid Function Profile blood test includes

  • TSH

  • thyroxine (T4)

  • free thyroxine

  • free triiodothyronine (T3)

  • thyroid antibodies

This can be organised for you at The Doctors Laboratory in London, or at The Clinic MK, Milton Keynes.

if you are diagnosed with a thyroid problem

  • both diet and acupuncture can help bring you back to balance, together with the right thyroid medication

  • a recent review shows that acupuncture improves both symptoms and test results (Cheng, 2018)

  •  be aware that many things affect thyroid health including sleep, overwork and stress