Thyroid UK
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really worried about blood results at 4 weeks pregnant

Hi all,

had bloods taken monday, id stupidly taken an extra 25mcg a couple of hours before the bloods were drawn, but really does it make a huge difference? my bloods are showing im a little hyper and im really worried...

Tsh: 0.04 (0.27-4.2)

T4:21.9 (10-22)

so obviously i will only be taking 100 eltroxin from now on, i was taking an extra 25 probably once or twice a week, but felt fine!

I was also taking nutri thyroid (im not now) which ive heard can affect your blood tests...

Really need advice, im terrified of miscarrying due to being over medicated, can that happen??

tia x

10 Replies

Well, as doctors like to say your t4 is 'within range' and your tsh is a little low. My understanding is that your t3 and t4 levels are more important than your tsh, and your t4 is fine.

Taking your meds near the test can make a big difference. I'm on t3, which is more immediate, but just to give you an example, last time I had tests taken, one test was nine hours after I took a very small dose of t3 only (result: hyper) and one test was 20ish hours after last usual full dose of t3 and t4 (result: normal).

When you think that levels are fluctuating all day every day, rising after we take our meds, then dropping until our next dose, this is just another example of that, just a snapshot.

Someone else may be able to more directly address your pregnancy concerns, but my off the cuff feeling is that your levels were different because your meds were too close to your test. Now you're on your usual dose you should be right where you want to be in terms of keeping your blood levels right. xx


There is a risk of miscarrying from under-treatment, I know that much. Since you took your meds so close to the blood test I would ignore these results as they are unreliable. Please ask your doctor to bring forward your next test so that you can re-check as soon as possible. Your body (with the addition of medication) is now supplying you AND your baby. You really do not want to be under-medicated at this time. At some point, I'm not sure exactly when, your baby's own thyroid will take over, but until that happens you must make sure you have sufficient thyroid meds for yourself and the baby.


I would be more inclined to go by how you feel. If you felt fine with what you were doing, then I would stick with it, including the Nutri Thyroid. Your fT4 was still in range just after taking meds, so is probably usually lower than this, and well within range.

I'm not an expert but have also heard more on the risks of being under-medicated rather than over-medicated.

Good luck xx


blood results are 'fine', if you are well like clarebear says.....'carry on'.

I know one hospital in London where their 'normal range' for TSH in 1st trimester of pregnancy is 0 to 5.5.

Whilst I do not agree with the 5.5, you can see their lower limit is ZERO :D

oh and your fT4 was high in range due to you taking the meds on the morning of the blood test, so maybe next time do not do this, take them 'after' the test :)


Tjanks, my doc said (via receptionist) they were perfect and not to change anything so i guess shes happy!


Thanks clare, i have been advised not to continue taking nutri as it has not been tested in pregnancy so i have stopped.


I found that Nutri thyroid had a significant effect on my blood test results, so you may find you need more thyroxine when you have your next test. Good that you are having another test so soon :) xx


I think it is important that you are honest with your dr/midwife about exactly what medication and what dose you are taking. Its not just you now and they can only look after you and your baby properly if you are honest. Pregnancy should be a wonderful time dont give yourself extra stress by self medicating. Thats just my thoughts on it but whatever you decide i hope you have a wonderful pregnancy xxx


Thanks helen, thats exactly what i think. I tild my doc i took the extra, however we had previously discussed me taking 125 once or twice a week and she was ok with that. However im going to sticj with 100 until my next blood test in 11 days. Thanks xxx


Hi T3 if taken at all , even in NDT does double the result. t4 does put it up a bit. Unfortunately only a very few docs, even Endos know this. vets have known for years, as i keep telling docs!I would pay for a correct test but be sure to have tSH, T4 and FT3, unless docs content to leave the dosage for now.

Usually the baby is safe, it is them other that the thyroid effects. ie feeling terrible etc. etc,

Best wishes to you and your pregnancy.



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