Change in levels, advice please?

[Nataliec92]

Hello,

I've recently posted due to being subclinical hyperthyroid. I am 18 weeks pregnant now and my levels haven't normalised as you'd expect in the second trimester. (Although my TSH has always been right on the bottom end of normal at around 0.35 to 0.67).

Endocrinology (UK NHS) are involved and taking a wait and see approach but I'm confused about the change in my levels. The only antibodies they looked at were TPO which was negative.

Latest results as follows 7/10/24:

TSH 0.03

T4 9.7

T3 6.04

My last results were 26/09/24:

TSH 0.02, T4 and T3 normal (don't have numbers)

And prior to that 10/09/24:

TSH 0.02

T4 11.2

T3 5.6

I know they can change here and there but I've never seen my T4 drop this much but T3 increase as well?

I don't have access to any further info on ranges etc for the above, but can this be expected at all? Or could the trend in the way the levels have changed mean anything in particular?

Thanks very much in advance for any suggestions!

[Jazzw]

They only tested TPO? That’s a shame—you need all the antibodies testing!

There’s still a possibility this is Hashimoto’s rather than the beginning of Graves (though in your last post you mentioned your sister has Graves, didn’t you?).

The good news is that at 18 weeks your baby should be making their own thyroid hormones and those levels - assuming the laboratory ref range isn’t too dissimilar to those commonly in use - aren’t too startling.

[Nataliec92 in reply to Jazzw]

Thank you so much for the reply!..

yes my sister had graves diagnosed just after her first pregnancy, she was on the verge of thyroid storm that discovered it I believe..

the only antibodies they checked was TPO and they said it was negative but I can't access the numbers unfortunately...

I think they're in the normal non-pregnancy ranges that I can find, but some ranges suggested that the T4 is barely normal at bottom end and T3 slightly over, I just thought it might be odd with the direction the numbers have moved in if that makes sense....

fortunately my symptoms have reduced mostly, I was having really bad bouts of palpitations and the endo said this was definitely related to the TSH which is in some ways a relief as Google thinks you can't have symptoms with low TSH so I was getting a little worried at one point.. just hoping they don't keep moving in those directions

[Jazzw in reply to Nataliec92]

I’m going to disagree with the endo on one point. The TSH in itself won’t be causing symptoms—it’s not even a thyroid hormone, it’s a signalling hormone that comes via a feedback loop from the hypothalamus to the pituitary to nag the thyroid to make thyroid hormone. Your TSH is quite low— hardly doing any nagging at all, which is why your endo is concerned about your FT3 being on the high end of normal. And it’s high FT3 that causes those uncomfortable hyper symptoms, not low TSH. I think I read on your last post that you had a nodule on your thyroid—it might have something to do with that.

But your FT3 has come down a bit, which is probably why you’re feeling better.

[Nataliec92 in reply to Jazzw]

Thank you, yeah I wasn't totally convinced myself as I've had them since 2018 coming and going in flare ups after I had shingles, so recently been contemplating pursuing pots as a possible cause for various reasons... my T3 was never all that high to be fair, and I've never had it tested prior to these recent ones I'm September, I think the T3 is in the higher end of normal though... I just can't get my head around it all haha just fed up of having flare ups with my palps x

[Jazzw in reply to Nataliec92]

I can only imagine. Here’s hoping things stay fairly stable now for the rest of your pregnancy. 🤞🤞