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Subclinical hypothyroid + TTC

Hi i'm 26yrs old and have been trying to concieve my first pregnancy for 10 months. 4 months ago i had bloods done which showed a TSH of 7.6 ( 0.1-5) t4 was normal. I was commenced on 25mcg thyroxine and 8 weeks later my TSH was 3.4. My gp was happy with this and didnt want to increase my thyroxine. My concern is im still not pregnant and was wondering if this could effect it. Thanks.

6 Replies

Never mind your GP being 'happy' - the aim is a TSH of 1 or lower once we take thyroid hormone replacements. Many GPs mistakenly think - or have been told- that the aim is a TSH within the range thus lots of suffering is caused. I assume you are still taking 25mcg of levothyroxine?

You need a new blood test and if you can afford it (we have recommended labs) you can get a complete set. The NHS have told GPs that TSH and T4 is sufficient but it isn't for those who remain undiagnosed/unwell.

All blood test for thyroid function have to be at the very earliest possible - fasting (you can drink water). This allows the TSH to be at its highest as it drops throughout the day. Doctors only look at a TSH it would appear. You should also allow a 24 hour gap between your last dose of levo and test and take afterwards.

You need TSH, T4, T3, Free T4, Free T3 and thyroid antibodies. If antibodies are present it would mean you have an Autoimmune Thyroid Disease called 'Hashimoto's' but treatment is the same as for hypothyroidism.

Ask GP to test B12, Vit D, iron, ferritin and folate as all have to be optimum. If low we will have clinical symptoms.

Pregnancy difficulties/miscarriages can be due to hypothyroidism. So, everything has to be optimum.

Always get a print-out of your results, with the ranges (ranges are important as labs differ) put them on a new post for comments.

We have two labs, Blue Horizon and Medichecks and they do home pin-prick tests.



Do you have a link for the evidence for the tsh to be less then 1? Thanks for your reply. Will definitely get those blood tests done.

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This is an excerpt which shows the reason why some people aren't diagnosed:

With all of these tests, your results could be anywhere within the range and you would be classed as "normal". If you are at the very edge of the range, either at the bottom or at the top, you could be classed as "borderline". Neither you nor your doctor truly knows what your normal is, if you did not have a blood test done before you became ill. There are also particular reasons why the blood tests remain in the normal range. If you are not converting from T4 to T3 or if your cells are not taking up the T3 normally, your T4 levels and your TSH levels will still show as normal.

The Broda Barnes Foundation tell us "Dr Barnes found that the primary reason for the inaccuracy of the blood tests for thyroid function is that the thyroid hormones are not utilized in the blood, but are utilized intracellularly. Therefore a patient can have enough thyroid hormones circulating in the blood to give a "normal" reading, but if the hormones are not getting into the cells, the patient will be hypothyroid.




NB: Dr. Toft, Consultant Physician, states in the British Thyroid Foundation newsletter Issue No. 23 that normal ranges are: T4 (10 – 25) and TSH (0.15 – 3.5). He also states that "the correct dose is that which restores good health; in most patients this will be associated with a level of T4 in the blood towards the upper part of the normal range or even slightly high and a TSH level in the blood which is in the lower part of the normal range. "



Hi I am under a fertility consultant and I know that they like the TSH to be 2.5 or less in a health woman. If you can try to get referred to a gynae/endocrine clinic as they have been fab with me. Good luck


your gp knows zip about thyroid a correctly treated hypo patient has a TSH of 1.0 or below and freet4 of around 19 and free t3 of around 5.5

if you have autoimmune hypothyroid which is common then any child is at high risk of devrloping any one of a number of autoimmune conditions

its my husband who had graves then hashis after our 2 daughters were born i am 100% healthy yet one daughter and 5 grandaughters all have Hashimotos and 3 have endometriosis too

email louise.roberts@thyroiduk.org.uk for a copy of Dr Tofts PULSE article and give that to your GP and insist on being tested and treated correctly

its vital that you start a file of results and you need

thyroid antibodies








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TSH needs to be in the low-normal range 0.4 - 2.5. Conception can be difficult when TSH is >3.0 and risk of miscarriage increases when TSH is >3.0. Dose is usually increased by 25-50mcg when pregnancy is confirmed to ensure good foetal development.

Show your GP the NICE guidelines:

-Refer to an endocrinology specialist all women with overt or subclinical hypothyroidism who are:

-Planning a pregnancy

-Check thyroid function tests (TFTs) before conception if possible.

-If TFTs are not within the euthyroid range, advise delaying conception, until stabilised on levothyroxine (LT4) treatment — discuss with an endocrinologist if there is any uncertainty about initiation of treatment or what dose to prescribe while waiting for review.

-Check that the woman understands that her dose of LT4 must be adjusted as early as possible in pregnancy to reduce the chance of obstetric and neonatal complications.

-Advise the woman to seek medical advice immediately if pregnancy is suspected or a menstrual period is missed.


Show GP: Management of primary hypothyroidism: statement by the British Thyroid Association Executive Committee

13. The serum TSH reference range in pregnancy is 0·4–2·5 mU/l in the first trimester and 0·4–3·0 mU/l in the second and third trimesters or should be based on the trimester-specific reference range for the population if available. These reference ranges should be achieved where possible with appropriate doses of L-T4 preconception and most importantly in the first trimester (1/++0). L-T4/L-T3 combination therapy is not recommended in pregnancy (1/+00).



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