Pregnant with tsh 17

Hi there,

I was wondering if anyone can help me with this problem. I had my thyroid removed 2 years ago and ever since I have been on euthyrox 125. My tsh 3 months ago was about 1.9, tf3 and tf4 always in the normal range. About 6 weeks ago I started ivf treatment, taking all sorts of hormones (estradiol/hcg/progesterone) and 5 days ago I tested positive for pregnancy. With the hcg blood test, I asked the doctor to check the thyroid levels, just to be sure and I could not believe it: tsh was 17!!!! Tf3 and tf4 are fine.

Apparently the estradiol interfered with the euthyrox! It seems to be a common problem but nobody told me!!! It would have been necessary to monitor tsh right from the start of the ivf treatment. I went to see an endo doctor and she advised me to raise the euthyrox to 188 (one and a half tablet of 125) immediately, which I did.

I was wondering if anyone knows how long it takes for tsh to fall? I feel we are running against time and I am terribly scared that I might loose the baby or that it might get problems due to the high tsh.

I would very much appreciate your help!

14 Replies

  • ... And I forgot.... Euthyrox is Levo-Thyroxine

  • Strictly speaking your offspring doesn't need TSH it needs FT3 as far as I know. So if your FT3 level is fine then nothing dreadful will have happened.

    But obviously your pituitary is trying to flog your non-existent thyroid into producing more thyroid hormone. So you definitely need higher doses of treatment, which you've been given. I would think your levels of FT3, FT4 and TSH should be tested at least weekly for the first trimester until such time as your offspring has grown its own thyroid. I'm not sure how frequent testing should be after that.

    I'm not medically trained, by the way. So I hope someone comes along and says they agree or disagree with what I've said.

  • OK, I'll disagree. A fetus needs T4, not T3. The placenta is full of T4 and rT3. The enzymes convert T4, AS NEEDED, to whatever hormone is necessary. They can only do that if you start with T4. The common practice is to just increase the T4 dose to 1.5 the normal dose. You've already done that, so that's good. You said your Total T3 and T4 were fine, but they need to be at the top of the reference range, not just anywhere within the range. There may even be pregnancy ranges that are higher than normal ranges. In any case, your Frees may drop, as you've already found out, because of the high estrogen. There's more info to get you started here:

  • So it's the placenta doing the converting from T4 to T3 or rT3?

  • Yes, placentas have high rT3, because too much T3 isn't good for the DEVELOPING fetus. The key here is that organs are being formed, and at certain points they need T3 to develop correctly, at other times too much T3 can impede the process, so more is converted to rT3. There are some interesting articles about how the proportions of T3 and rT3 wax and wane as a tadpole forms. Sorry, I don't have the link, but remember it was fascinating reading.

  • Thanks for the info. :)

  • Hi, thank you for your answers! I had no idea how it works. So does the levo-thyroxine help to keep T4 and T3 in the upper normal range, too? I suppose the danger is that those two will get worse, too, if untreated.

  • This is an excerpt from a previous post:

    NICE recommends that hypothyroid women planning conception should discuss it with their doctor to ensure TSH is in the low-normal range 0.4-2.0 with FT4 in the top 75% of range. TSH >2.0 can make conception more difficult. Levothyroxine is usually increased by 25mcg-50mcg when pregnancy is confirmed to ensure good foetal development during the first trimester when the foetus is dependant on maternal thyroid hormone and to reduce the risks of miscarriage and post-partum thyroiditis. They also advise referral to a specialist.

  • Dear Pixieling, you are right to be concerned about your thyroid function during pregnancy. I highly recommend looking at, she had pregnancy complications from undiagnosed hypothyroidism and her blog articles are excellent. Bear in mind she is in USA so you will need to apply her figures etc to your situation.

    Hypothyroidism may have caused primary infertility for you.

    Good luck and take care of yourself and your little one!

  • Hi there and thanks very much for telling me about the blog. As it is, I found out something else by reading it. I did not leave enough time between the levothyroxine and the vitamin supplements I have to take - which contain iron. I waited for about an hour. Anyway, I have told my doctor about this now...

  • Pixieling, That's a substantial dose increase and should work quickly. I'm also thyroidless. I'd been off thyroid meds for 4 weeks and when I resumed Levothyroxine TSH fell from 107 to 22 in 14 days, and was down to 0.16 in 8 weeks. I hope all goes well.


    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.

  • Hi, thanks this gives me hope! I had no idea, levels can change that fast. Hopefully it works with me, too!

  • Pixieling, how did it go how are you doing?

  • Hi missmystique,

    not very well, unfortunately. I lost the baby at week 8. Of course it is not possible to say why exactely. One doctor was blaming the other and vice versa for not telling me about getting an endocrinologist right from the start. But what is worse, nobody can properly explain to me what the risks are if we try it again and how we can eliminate risks as good as possible.

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