Early pregnancy- very low TSH

[Fizzyinch]

Hi all,

I wanted to get my thyroid levels checked *before* falling pregnant, to make sure that I had good levels for conception ( have previously struggling getting my T3 up and i have read that TSH should be around 1) - However had positive pregnancy tests last two days!

By the time I managed to get an appointment, it was past my ovulation date and I was technically pregnant, albeit a few days... however didn't know at the time. Could the test be affected by pregnancy this early?

Usually I test first thing in the morning, fasted, no levo etc. however couldn't get a test until 10.30am and had breakfast, so i am not sure how accurate this is.

Dose: 75mcg (M-F) 37.5mcg (S, S)

TSH: 0.07 (0.35- 5.50)

T4: 18.8 (10.5- 21.0)

T3: 4.7 (3.5- 6.5)

They say for pregnancy you should increase your dose by 25mcg, but concerned the GP will not want to increase yet because of low TSH.

My question is, is there any concern / miscarriage risk for having very low TSH? I can't seem to find anything online, only if TSH is above 2.5.

I should add, I have been feeling really good on this dose ✌️

Thank you

[HealthStarDust]

They say for pregnancy you should increase your dose by 25mcg

This is endorsed in lots of literature and forums etc but there are no official general guidelines on it (UK). It is best to be guided by TSH and FT4 by regular testing and stabilising TSH around 1 or below prior to conception. And, it’s important to realise that many women don’t even need to change thier dose during pregnancy (yes, it does happen).

Your numbers look good for pregnancy, and I would not be inclined to increase based on those numbers yet. Make sure to take an another test by 4th week of pregnancy at least. Be guided on your symptoms with when to take this next test. Your body will let you know if it’s needed sooner.

Congratulations. Try to relax. All this stressing won’t do you or your baby any good. As I said, your numbers are ideal for a pregnancy test especially early pregnancy.

I’d encourage you to seek pregnancy related apps/forums and find other women in your positions for peer support as well.

[Fizzyinch in reply to HealthStarDust]

Thank you so much for the helpful response. Trying to relax, easier said than done 😀

[HealthStarDust in reply to Fizzyinch]

I know. I’ve sadly been where you are and I wished I had received better advice. If it helps, when I met with a preconception endocrinologist the main thing they said to me was it’s common to increase dose, yes, but it’s best to be guided by blood test results as far as possible hence the emphasis on getting things to a good level prior to pregnancy. Your TSH and FT4 are great.

Best 🫶🏽

[HealthStarDust]

P.S.

Usually I test first thing in the morning, fasted, no levo etc. however couldn't get a test until 10.30am and had breakfast, so i am not sure how accurate this is.

I wouldn’t say inaccurate, but yes, it is inconsistent due to how you normally have blood tests. With that said, I feel during pregnancy it is important to know how much hormone is circulating around with the replacement hormones. And, even so, based on when and how you have had this test, your numbers wouldn’t increase or decrease massively as it’s a storage hormone.

I hope that helps.

Congratulations again 🫶🏽

[Fizzyinch in reply to HealthStarDust]

Thank you, and i wish you all the best with your journey too.