Advice needed on "normal range" for hypothyroidism


I had a very early miscarriage recently, and can't help thinking perhaps it's my underactive thyroid that contributed.

I spoke to my doctor about it, and they said with my current dosage that my thyroid results are within the "normal range" (TSH 2.34 and FT4= 10). even though when ive been doing my own research, it states that ideal level is TSH<2 and FT4 between 16-21. The doctor still said she's not going by these "ideal levels for pregnancy" as mine are within normal range and no further action would be needed even if I was still pregnant.

I'm worried in my next pregnancy they will keep telling me I'm normal, even though they are not at the ideal level at all. Has anyone got any more information on these "ideal levels" and what I should do if I fall pregnant again? Do I need to see an Endo to get my levels right before trying to concieve again?

Thanks very much in advance.

38 Replies

  • Hi we also are ttc, (so far 4 years without succes) :( it was going through the fertility investigations my thyroid was flagged up underacrive. The fertility doctor was saying that was likely cause of the infertility, as I was likely not ovulating due to it. They told me the same, TSH under 2 and t4 under 20. I have also asked the go to test my progesterone as I have heard that can take a hit too when your hypothyroid. He just shrugged me off. Had progesterone blood tests done privately with the fertility specialist, which proved I wasn't ovulating. The blood test had to be over 30 to trigger ovulation, my blood results never peaked past 19. I know this was the case as we are doing the clear blue trial with gone dual hormone fertility monitor which was saying the same thing. Since starting the Levo, not much improvement. As I went hyper for a bit. Which made my cycles about 23-24 days so my luetal phase was only about 8 days. Not long enough to conceive. If you do fall pregnant again I would be on tor doctor like a rash. Keeping a close eye on you're levels maybe every month, there are a couple of ladies on the infertility network who have had early miscarriages who are thinking the same as you, that if their levels aren't enough it's not enough to help a foetus develop. My fertility doctor told me they will usually increase your thyroxine by 50mcg to start with u see the assumption your pregnancy progresses, so I would Defo be testing early and seeing him straight away when you know xxxx

  • Thanks so much for replying and I'm glad that you've taken it in to your own hands by seeing the fertility specialist. Has your new dosage helped kickstart ovulation?

    My thyroid levels are now TSH 2.34 and T4 is 10 which the gp said is normal. When I did fall pregnant this time I made an appointment to see her straight away and they did my bloods. As these results were within "normal range" she said there was no need to increase my dosage or make any changes. I'm so confused, as I thought that in pregnancy the dosage automatically increases?!

    Also about getting my levels down below 2, she's not entertaining that either. She keeps saying my levels are normal and I need to "stop getting stressed" by reading too much on the Internet!! Its just stressing me out more that she doesn't want to get my levels lower than 2.

  • Proud mummy, u suspect we have the same gp!! Mine was reluctant to even tell me my blood work just so i could post it on here!! Grrrr. Yes the fertility doctor said it defianatley increases by 50 mcg on top of what your already taking, so if your on 25 it would jump to 75 and so on. I would definalty be having a conversation with him or the midwife when you have your booking bloods. Your range may be normal for you, but not to support a little one too! Yes have had 2 + ovulation months since being upped to 100mcg a day, and my body tells me when I need the dose increasing as my cycles get longer and no positve ovulation. I think your absolutly right to be concerned with this- if we ever get blessed with a bean I will become the worlds biggest pain the arse with my doctor as its one thing fobbing me off but not risking a baby we've been trying years for. Good thing with you is your obviously ovulating, which is great :) xx

  • Proud mummy Re you taking Levo At the minute? Xx

  • That's great the new dosage is working and you've been ovulating :-)

    Yes I'm on 50mg Levo at the moment. When i fell pregnant and they took bloods they said they won't increase my dose and to just remain on 50mg.

  • Hmmm. Thats baffling really. I wouldn't want to blame a miscarriage on the hypothyroid as I guess thins can go wrong and statistics for miscarriage are something like 1 in 4 now?? My gp is the kind of person that would use that statistic to fob me off. I thinks the problem is my gp and a lot of others, are uneducated in the ins and outs of thyroid conditions. And yes I saw the fertility specialist but at almost 200 pounds a pop to be told what dose I should be on when I should be getting that advice free from my own gp is a poor show!! Xx

  • Tsh of 2.34 and a free t4 of 10 is in no way normal

    sounds very much like central hypothyroid too with a low tsh versus such a low free t4

    get a doctor who knows thyroid not your current idiot

  • I'm just considering if I need to see an endo. My GP had a meeting with the other Gp's in the surgery- all which agreed with her advice and suggested there was no need to up my dose and that my bloods came back normal.

  • My gp refused to refer me to an endo as I'm In the normal range...

  • Did you find your own endo in the end? I think I will have to do the same. It's so ridiculous that you've had to spend that money privately where your gp should be better educated. I'm even more annoyed now and just want to get the right advice from a doctor.

  • Nope I haven't got in touch with a private endo yet, and yes it's disgusting that they are so uneducated and it's a fight to get the help you need. Makes me wonder if we hadn't gone down the fertility route wether this would have ever even been treated. I wanted to see an endo as I don't even know if they have tested me for the Hashimoto antibody or what sort of condition my thyroid is even in. All I know is I started kn 25 mcg and now I'm on 100. And every time I've had to push and nag for blood tests, which have always needed dosage adjustment. I feel like I'm a second class citizen with the docs it's really annoying.

  • You would need to be very sure any Endo you see knows what they are doing and theres precious few of them too

    Thyroid treatment is scandalous

  • Proud-Mummy, I'm so sorry for your loss.

    NICE recommends the TSH of women planning conception and newly pregnant should be in the low-normal range 0.4-2.0 with FT4 in the upper range. Levothyroxine may be increased by 25-50mcg when pregnancy is confirmed to ensure good foetal development.

    I suggest you show your GP the NICE CKS guidance


    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.

  • Thanks Clutter for replying with those guidelines. I showed my GP these and I just can't understand why she won't listen to me. She just kept reiterating that my levels were within normal range and no action needed. She said if I was still pregnant then sbe wouldn't have increased my dose either as my bloods were within normal range. She is completely disregarding this information about the TSH levels needing to be lower than 2. I'm really upset as I don't want to get stressed about my dosage if I fall pregnant again. I don't know who else can help me. Perhaps I should be seeing an Endo?

  • Is there another GP in the practice you could see? Or another practice in the place you live?

    This GP is likely to make you very ill in the long run. If you're already on 50mcg of Levo, you're undermedicated.

  • The GP's all had a meeting together and agreed that no action to be taken as my levels are within reference range. It's extremely frustrating. I think I'll still go see another doctor and also see if I can see an endo as I'm really not happy with the advice I've been given especially after seeing all the replies on my post now. I've totally been given insufficient information from my GP

  • Scary. That means every hypothyroid patient in your practice is probably undermedicated. That's negligence on a large scale.

    There's an article available from admin here written by an endocrinologist called Toft who states that many with hypothyroidism need replacement hormones which take their TSH below 1.0. If your FT4 is 10, there's no argument at all for you being overmedicated - I really don't understand why they're so reluctant to raise your dose another 25mcg.

  • Proud-Mummy, I'd make a written complaint that your GP ignored NICE CKS and you feel this may be why you miscarried and I'd ask to see another GP or change practice.

    TSH 2.34 is too high anyway. Most people feel better with TSH around 1.0 with FT4 in the upper range. Read Treatment Options in Email if you'd like a copy of the Pulse article to show your GP.

  • Thanks Clutter for this article. I'm definitly going to present this information to another GP and see if I have more luck. Also I just remembered that even the doctor at the hospital (dealing with the miscarriage) seemed confused about this TSH <2 information and wasn't concerned about needing to amend my dosage.

  • Your GP is plain ignorant and is doing even the healthiest person no good at all

    get one who bothers to research and accept you have done your research

    on the ? Of pregnancy i have to warn you to think very very carefully indeed as to what auto immune illness your child could well inherit because of your hypothyroid

  • How do I avoid that happening? I already have a daughter and developed my hypothyroidism after having her

  • Hypothyroidism can run in families sometimes. It often occurs after a pregnancy because a woman's immune system goes a bit haywire during pregnancy. It's thought someone is three times more likely to develop autoimmune hypothyroidism if they have a parent who is hypothyroid. Bear in mind that about two percent of the population have autoimmune hypothyroidism, so the overall chance is not that high.

  • Sometimes the TSH doesn't rise as much as it should do for a low fT4. This can be due to lots of (minor) problems, such as dieting, depression or because the TSH was suppressed during autoimmunity before the hypothyroidism set in. Whatever, it doesn't matter too much but it is important to keep the fT4 in the upper half of the reference interval prior to and during pregnancy.

    If you are trying to conceive again or become pregnant insist on an increase. If you get no joy ask for a second opinion or if that doesn't work make a formal complaint. You would probably be better off on a higher dose now although this is not necessary if you are doing OK.

  • So my TSH is 2.34 and FT4 is 10. FT4 is definitly at the lower end rather than higher. I can't even get a 2nd opinion at my doctor surgery as my GP already had a meeting with the other GP's and they all agreed on the advice she gave me which was "stay on current dosage and no further action because results are within reference range"

  • Although your lowish hormone levels are probably not the reason for your miscarriage it can't be ruled out and is an unnecessary risk. If you are trying to conceive I'd insist on a referral to an endocrinologist. Take your partner along for support, it should do the trick. An fT4 of 10 is low even if the TSH isn't very high. They haven't measured your fT3 and I suspect this would be low also. If you can't get anywhere then the only option is to make a complaint.

  • Proud mummy I also have two sons, there's no guarantee you wont pass it on to your children but some of it must be non hereditary as there's no history of This in my family on either side and the fertility specialist told me its sporadic and has nothing to do with genetic lines. There is however diabetes on both sides and neither me nor my husband have developed that. Just shows it's not as black and white. I too developed this only last year when I was 34 after my two children who for the record are thriving! :)

  • I am so sorry for your loss. Did they test you for mthfr mutations? These can also cause miscarriages. I just read about that yesterday on if they are disinterested in testing and you want to check, you can get genetic testing on and look for yourself. It's treatable. Doctors are largely way behind. Sometimes we have to figure it out on our own and hand feed them. The site I mentioned also discusses alternative possibilities. The comments section is very educational also.

    All my best, jen

  • No I haven't been tested for that at all. I'll definitly check out that website. Thanks so much x

  • Just wanted to thank everyone for their responses here to my post- really appreciate it. Definitely armed me with knowledge for my GP appointment earlier. Wanted to post an update- the other gp today was so helpful and knew about the NICE guidelines and has put my dose up to 100mg and will reassess in 6 weeks if we are under 2 for TSH and top range for T4. Thank god I now have seen someone who knows what they are talking about.

  • Proud-Mummy, that's good news. Try sticking with that GP for anything to do with thyroid. When you have the next thyroid test arrange it early in the morning when TSH is highest, and fast (water only) as TSH drops post-prandially. Post the results with ranges in a new question and members will advise.


    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.

  • Thanks I'll definitly do that. I've now asked them to test my T3 and Thyroid antibodies too which I checked hasn't been done before

  • I just wanted to make sure the message has got thru to you that doctors (both GPs and endocrinologists) often know very little about thyroids. They are willing to allow people to suffer with being hypothyroid, and to put pregnancies at risk. It's really up to you/us to make sure doses are reasonable and that you take what GPs say with a pinch of salt!

  • Really glad you've seen someone who has helped. I've been through a similar scenario recently and it can be so upsetting. Best of luck with everything.

  • Have you thought about suing your GP I think you have a good case. Her treatment of you is appalling.

    Do you feel well I should imagine you feel really tired and unwell with your T4 so low. I had 2 boys while an undiagnosed hypo. thankfully I didnt miscarry but needed fertility treatment. Anyway it was really hard during the pregnancy and when they were small. I was far too tired to be at my best or to really enjoy their babyhood. JUst a thought that maybe for now you should focus on using this forum to get really well which might well mean self treatment or paying privately to see a doctor on thyroid uks website. You will enjoy a pregnancy and be a better mother if your really well. Think about putting a pregnancy on hold for a while. And change GP practice the one you are in is no good for you or any future children.

  • Did they not detect the thyroid problem whilst having fertility treatment? The gp I saw today was far more in the know and also was really interested in this support network website so he can recommend it to his thyroid patients. I'll see how it goes but I think I will only see him now in regards to any thyroid related issues

  • No they didnt because they are totally fixated on TSH levels and mine never got to five. I had loads of symptoms and a skin condition you only get if hypo. I felt terrible for thirty years before a doctor I found out about from this forum started me of thyroid meds and the road to much better health.

  • Oh I'm glad you've found a good doctor that treated you. Are your boys ok aswell- did you get them tested for thyroid too?

  • My elder boy had his TSH tested recently and a part of a raft of tests for his frequent loose stools and it was borderline hypo. I said to my doctor that he had no symptoms, had a normal temperature, is a fit and lively boy and finds blood tests distressing so |I didnt want him tested again. that I was well aware of the symptoms and would keep an eye on him. If he was tested again and it came back raised again I would not want him treated unless he became unwell. The doctor is insisting he have another blood test. They treat blood tests not people and dont even know the symptoms of being hypo to assess any other way. It wouldnt be too bad if the TSH was a reliable test.

    My younger boy is symptomatic. He has put on a lot of weight this year, become increasingly worried and serious and was described by an OT who see him at school for his dyspraxia as not very alert. The GP has agreed to test in the new year but does not even think to examine him to see if he has a low temperature( Which he has) or take his pulse. I think I have a battle on my hands to get him some kind of treatment. I dont really want him to be put on the usual NHs medication as is causes weight gain for so many people.

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