Thyroid UK
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TPO - what does this mean?

Hi all, I've been through the mill a bit - been on 50mg for a few years as underactive, we started fertility treatment a few years ago (actually due to male factor) but after a few failed implantation I started to push to get my results my TSH was between 2.9 and 3.5 and for pregnancy they prefer it lower than 2.5 so over time the increased my dose so I was on 150mg feeling much better with a TSH of 0.04 which my GP said was ok

We then finally got pregnant but sadly lost the baby at 10 weeks

Now we are about to try again but fertility clinic said I was actually slightly surpressed (I really hope this isn't what caused the miscarriage because I've been fighting to be heard on this for years) I try not to think about that though and just move on

Anyhow my dose was reduced to 100mg last week as my TSH was still 0.02 but since I reduced I've been feeling terrible, back to brain fog, dull headache etc it's been a few months now since miscarriage so don't think it's hormonal now - what could be going on?

I did look back the results I was given to see if I've missed anything and I found done notes back from before we started IVF I've written TSH 2.94, FT4 16 and TPO 2.0 - Now I remember asking for antibodies test but was told it was ok but surely 2.0 means something?

Sorry for long post but I've just had an awful time and I don't know how much more I can go through and just wish I had someone who could really look into all this properly 😔

8 Replies

The first thing you need is to get a proper set of your latest blood test results. If you haven't had your bloods done recently then get them done and make sure you get a print out of your results or if you're in the UK, register online for all your blood test results including historical ones. You do this by asking your GP reception for a password and you may need to complete and sign a form and provide ID, make sure you ask for enhanced access for blood tests results. When you have the results, post them on here along with the laboratory ranges. Then people will help you to understand what has been going on and what you could do to improve things.

At your next blood tests make sure you get:







vitamin D

Thyroid Peroxidase antibodies

Thyroglobulin antibodies

If your GP won't do these you can get them done through a reliable online laboratory. You will find information on the Thyroid UK website for reliable laboratories in the UK. Elsewhere you may need to do some research.


Many thanks for your reply I didn't realise you can get online access to results, my GP did carry out all of those other vitamin tests about 8 months ago and they were all ok then (I took that advice from someone on here actually this is really helpful!)

I'm booked in to test again in a couple of weeks after the change in dose so will push again to check all things because I have suddenly felt so bad again

If not I'll look into private testing, is that blue horizon you are referring to yes?


Have you actually seen the results of B12 - Folate - Ferritin - VitD ? Low B12 is somehow involved in fertility/pregnancy - *Could it Be B12 ?* - book by Sally Pacholok mentions this. Your result needs to be near the top of the range.

Are you still treating the low iron ?

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Depending on your lab reference range. I don’t think 2 is at all significant - in my lab >100 is positive (mine were >1600).


I guess either way even if I do have antibodies the main thing is to moot it closely and keep my TSH below 2.5 but not too low and both clinic and GP are doing that - I remember them saying they can test all these things but the treatment would be the same anyway

Maybe I just need to try and relax and continue with my 4 weekly checks


I really don't think your miscarriage was due to your low TSH. I'm not a specialist - not even medically trained - but I do know that the only reason they want your TSH below 2.5 is because that means that your actual thyroid hormones are well in range. The TSH is a pituitary hormone, and is just a marker, an indicator of thyroid status. But, once you're on thyroid hormone replacement, it doesn't matter how low it goes. The important numbers are the FT4 and the FT3, and I'm pretty sure your doctors were making sure that they didn't go over-range.

Everybody has some antibodies in their blood. The question is: how many? I think 2 is the lowest I have ever seen! So, I really don't think they are a problem - unless your lab uses a very peculiar range. :)


Thank you so much for putting my mind at ease


You're welcome. :) Good luck for the future.

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