TSH of 3.1 first trimester - normal?

[DaisyEM]

Hi all,

I’m 9 weeks with baby 2. My thyroid has always been on the sluggish side (usually around 2.8), but I’ve never been on medication for it. I requested to have it checked by the GP when I found out we were going expecting and it was 2.8. Google told me that it should be under 2.5 for first trimester, but GP said she had never heard this before and said it was fine. I was happy to take her word for it, but having just had my booking appointment my bloods from that have come back with TSH of 3.1, so obviously it’s increased since the first test.

Can anyone advise me if this is an ok level for the first trimester? As the GP seems totally uninterested in my first test results, I don’t know whether to go back again and point out that it seems to be rising? Google seems to suggest it’s higher than it should be, but GP thought otherwise, so I’m not sure what to think 🤦🏻‍♀️

You should see an endocrinologist, should be lower.

Having said that my Fertility Specialist said that for TSH to cause damage it would have to be very high.

Anyway, yo be safe check with am endocrinologist they will also check other related things T3 and T4.

Have you had your first midwife appointment already? I’m not in the UK and this (TSH and free T4) is something that is routinely checked at the first pregnancy appointment. Did your GP check your T4 and/or T3 as well? Were these values within the normal range? It’s very strange to look at TSH alone - it”s not a thyroid hormone, it’s released by the pituitary gland to control the work of your thyroid so you want always to see how much your pituitary gland has to interfere an what effects this has on the thyroid (T4 level at least)

TSH in the first trimester should be going down. It’s the lowest at 9-12 weeks. If it’s going up you should be seen by someone who is more knowledgeable than your GP.

@Olivie12 thanks, that’s reassuring. I’m not sure how easy it is to speak to an endocrinologist (I’m in the UK), as I’ve tried to raise it to my GP and they said they had never even heard of it needing to be under 2.5 in pregnancy and dismissed it.

@CortieTat yep the bloods are from my first midwife appointment last week. I did ask for T4 to be checked too but at the moment the results are just showing TSH so I’m guessing only TSH was tested 🤦🏻‍♀️ from what I understand it’s normal for it to go up in pregnancy as the baby relies on your thyroid hormones in the first trimester putting more pressure on it. So I’m not sure if the increase to 3.1 is alarming. I’ll try the GP again but I suspect they will brush it off again 😖

GPs are crap at diagnosing/treating thyroid issues. The ideal in pregnancy is a TSH under 2 / 2.5. I went to a private endocrinologist because I wasn’t happy with being dismissed by my GP and they confirmed that they’d like to keep the TSH under 2.5 in pregnancy. (For what it’s worth, I have hypothyroidism and even when I’m not pregnant I start to feel not my best when my TSH goes over 2). Also keep in mind that the TSH often raises during pregnancy, I’m doing blood checks every 4 weeks as advised by my endocrinologist to monitor it closely.

This may help:

www.btf-thyroid.org/thyroid-disorders-in-pregnancy#:~:text=positive%20pregnancy%20test.-,Hypothyroidism,3.0mU%2Fl%20after%20that.

@Cinai thanks, was that a private endocrinologist? I think because I’m not considered hypo by NHS because my TSH is under 4,5, they aren’t interested. Initially when I was talking to a GP about it she thought I was on medication, but then when she realised I wasn’t she just brushed it off, and also said she had never heard of TSH needing to be under 2.5 in the first trimester.

@JudyJulie thank you. I wish I could find some NHS documentation that says the same, as I don’t think my GP will take anything else seriously 😖

TSH goes down in the first trimester and then up. There are large studies showing that it’s the case: https://www.thyroid.org/patient-thyroid-information/ct-for-patients/october-2016/vol-9-issue-10-p-3-4/

if your thyroid hormones (T4, T3) are in the normal range I probably wouldn’t worry but if not I think it’s worth pushing your GP for answers.

@CortieTat thanks for this, I thought it was the opposite for some reason! I've text my midwife but no reply so far so trying the GP instead now. Thanks for your advice x

@DaisyEM I was in a similar situation to yourself, subclinical hypothyroidism, GP guidelines didn't recommend treatment unless tsh went over 10. I learnt later through thyroid and fertility/pregnancy specialists, this was the 'non pregnant' guidelines and under 2/2.5 tsh is best for pregnancy.

I don't want to worry you but I had a recurrent early miscarriages and it was partly down to thi so I went privately to a gynecologist who specialised in recurrent miscarriages and he prescribed low dose thyroxine of 25mg, which I took ttc and still taking throughout pregnancy, dose hasn't needed any change. NHS now acknowledge this and prescribe the treatment. My tsh has been stable since.

You'll need to be referred to be under an endocrinologist as baby depends on your thyroid until 24ish weeks before their thyroid is fully functioning. But I'd go privately and get the thyroxine guidance to give to your GP.

www.btf-thyroid.org/thyroid-disorders-in-pregnancy

Show your GP this link, British Thyroid recommend less than 2.5 in the first trimester and less than 3 second trimester onwards. So your levels aren't too much higher, but need checking out properly

@T2024 @Nejnej thanks both, I’m starting to feel quite worried about it now 🤦🏻‍♀️ the most recent results of TSH of 3.1 was from a week ago, and it had gone up from 2.8 about 4 weeks before that, so my concern is it’s continuing to go up 🤦🏻‍♀️ I’ve ordered a private blood test so I can get T4 and T3 checked too. I tried to call the GP about it yesterday but the receptionist said a two week wait just for a telephone appointment and that the GP had marked my latest TSH result as normal in pregnancy 😖

@CortieTat it’s worrying me now that my TSH seems to have gone up during my pregnancy, do you have any ideas why this might be?

I found numbers from my first pregnancy, and before pregnancy mine was 2.6, and went down to 2.1 by my booking appointment, so going in the direction expected like you mentioned. I’ve tried looking online but I can’t figure out why it would be going the opposite way during 1st trimester 😖

I’ve ordered a private blood test to do a full thyroid function, so hopefully that’ll give me a clearer picture 🤞🏼

I had a similar issue in my first pregnancy and essentially no one was interested because I wasn’t already on thyroxine. My midwife bloods showed a high TSH and I was told to increase the meds, but when I said I wasn’t on meds, apparently it was fine after all and didn’t need treatment

The NHS can be quite woeful towards thyroid issues. My elderly DGM was taken off her thyroxine after decades of being on it and a ‘normal’ blood test result.

Ask the midwife to refer you to the obstetrician. They will seek advice from endocrinology.

I’m really sorry but I don’t know. My interpretation of the TSH going down in the first trimester is because the body makes much more progesterone than normal which takes care of raising temperature and metabolism (normally it’s the job of the thyroid). Mine went down like a led balloon but I have never had thyroid problems, my THS always follows the seasons too.

I would get the free T4 results and consult some more clued up than your GP. And please don’t panic. It’s usually harder to get pregnant with higher TSH (malfuctioning thyroid can affect ovulation because why would your body want to reproduce if you are lacking energy?) and you are already pregnant.

@DaisyEM That's not too big of a jump in 4 weeks which is a good sign, but it's best to get a private test so you know your t3 and t4.

I found my tsh dropped considerably at weeks 9-12ish as high levels of hcg can have an effect on tsh level. If you can, go privately to a consultant app if the endocrinologist maternity service is going to take a bit longer.

I've attached the info I found online when I was in first trimester x

@GodspeedJune I’m also finding that a lot of the guidance online does appear to be in relation to patients already on medication for an underactive thyroid, so it’s quite confusing! My GP initially thought I was on medication and then lost interest when they realised I wasn’t x

@RosesAndHellebores thank you. I’m already consultant led so I’m wondering if maybe I go straight to the consultant about it rather than midwife 🤔

@CortieTat absolutely no problem, just thought I would ask. Thank you, that’s reassuring, especially as when my TSH was 2.5 it took 8 months to conceive DS1, whereas with my current pregnancy it happened first time with TSH higher. I won’t worry about it but will definitely seek further advice x

@T2024 thanks so much, this is really helpful ☺️ x

So I did a private blood test to get a better picture of what’s going on, and my TSH has come back at 1.56?! How is that possible after the last reading was just over 3 a few weeks ago 🤔 FT4 is 14.4 and FT3 4.1. If anyone can shed some light on these numbers I’d greatly appreciate it

@T2024 @CortieTat @Cinai @GodspeedJune @RosesAndHellebores @JudyJulie @Nejnej @Olivie12

1.56 is great, brilliant news. It must be your hcg levels repressing your tsh now that the levels are so high. Mine dropped from 1.8 to 0.39 in 4 weeks in the latter of the first trimester due to hcg levels.

How many weeks are you now?

My endocrinologist always looks for the ft4 being good, mine usually sits around the 14 atm being pregnant. I think ft4 is the one that baby needs to convert for itself x

@T2024 thanks so much for replying ☺️ ah that makes me feel better that your TSH did the same! I’m 11 weeks now and last time my bloods were taken was 8 weeks which is when TSH was 3.1. Guessing if you’re FT4 is around 14 during pregnancy then mine at 14.4 must be fine? At least it’s one less thing to worry about now 😅

It is great news!
It’s also possible that your previous result was affected by something. It used to be common for biotin to interact with TSH tests, so if you take a prenatal that contains biotin (vitamin H) the results could be affected by this. Different labs use different technologies too.