Thyroid UK

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So some of may have read my previous posts. I have thyroid antibodies 109-Thyroid peroxidase antibodies. I have read thyroid peroxidase antibodies especially are associated with an increased risk of miscarriage. I have had 6 early miscarriages. The miscarriages have finally led my GP to prescribe me levothyroxine due to an endocrinologists letter. So, my TSH was at 1.73 and I was pregnant with thyroid antibodies. He told me take 50mcg of levothyroxine as 25mcg is too low. I was told these new blood test results are a bit abnormal and I am adjusting my dose to about 36 mcg a day. I started taking the thyroid medication at 50 mcg and below are my levels on MAY 11th:

TSH -0.01

Thyroid peroxidase antibodies- 109

T4- 27

(Not sure about T3 I will need to pick up my results tomorrow to check what else is on there , these were told to me on the phone and I forgot ask about T3 )

My questions:

Could this TSH and T4 be a cause of miscarriage?

Could this affect my next ovulation which should occur in about 8 days or so.

Could this affect me getting pregnant?

I was worried about increased TSH in pregnancy now it is the opposite and I worry was this the cause of my miscarriage?

I started adjusting my dose 21st May when should I see results? (Note: I am skipping the weekends and taking 50mcg mon-fri, which reduces overall dose as I was told it works in blocks of 5 days?)

The GP said she is not a specialist in this so she can't say. However, the endocrinologist said it could affect ovulation. I have reduced my dose to get to the 'perfect' levels he wants me to be at. He wants my T4 to be in the upper range around 23, so hopefully this will be the correct dosage now. I see him again in 7 weeks with with another blood test, fingers crossed the dosage has been corrected.

6 Replies


It should take 2-3 weeks after reducing dose for FT4 to drop and TSH to rise. I think it is highly unlikely that mildly elevated FT4 and suppressed TSH have anything to do with your miscarriage. Suppressed TSH is helpful in dampening down antibody levels as low TSH means little or no stimulation of the thyroid. It is low FT4 and high TSH which cause difficulty conceiving and increase the risk of miscarriage.

I think your specialist is talking alarmist nonsense when he says FT4 27, which is mildly elevated, will affect ovulation.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

in reply to Clutter

Thank you for that response. That's good to know it should not affect ovulation. He said about the egg attaching process that it will effect that to and that it would be unlikely with these results to be pregnant. I like asking on here as I like to hear from people with have experience with thyroid problems as you have first hand experience. I thought so too that a suppressed TSH would mean more success. Anyway I shall see how things go next time with these levels and if he is happy with my results

Orangepie my antenatal clinic likes pregnant women to have a TSH below 2 so I would've thought your pre-thyroxine tsh would be ideal for pregnancy? So maybe no thyroxine needed at all?

in reply to Molliemoo1

Molliemoo1 My endo likes to see my T4 in the upper range at 23 for a successful pregnancy in my case , before it was 16.4. In my previous miscarriage at 5 weeks my TSH quickly shot up to 2.84 without taking thyroxine. This time it didn't shoot up as I was on meds. My NHS endo says I need it for my antibodies as there is evidence to show that it helps if you have normal thyroid levels just need to get the correct dosage. With these antibodies if i don't take thyroxine my TSH probably will shoot up in pregnancy like it did when I did not take it. It is a matter of correct dosage.

If you read on NHS TABET they are interested with women with normal thyroid levels ,which is the case for me.

The NHS study focusses on women like me with euthyroid TSH level and antibodies but are still given thyroxine.

I have been told to take aspirin everyday too. This is what the thyroid TABLET study states:

'The researchers are particularly interested in seeing whether a drug called Levothyroxine reduces the risk of miscarriage in women who have thyroid antibodies even though their thyroid hormones are in the normal range.'

In America there is lots of studies to show it reduces miscarriage rates with women with normal TSH level. I also read women with normal TSH level and these antibodies are much more likely to miscarry. I am trying to find out the science behind this.

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in reply to Clutter

Ooh thanks my bedtime reading !

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