Hashimotos and pregnancy : Hi everyone I've... - Thyroid UK

Thyroid UK

113,180 members131,494 posts

Hashimotos and pregnancy


Hi everyone I've recently found out I'm pregnant, currently 6 weeks.

I was referred to an endo and had appointment October of this year before I found out I was expecting.

He put me on a trial on liothyronine 10mcg and 75mcg levothyroxine.

Endo wanted me back in 6 weeks to get bloods done - the results were tsh 0.86 and t4 12.7. Conception would have occurred one week previous to me getting my bloods done.

Once I found out I had conceived I contacted Endo and they are happy enough with bloods for another 4 weeks. However I'm feeling dreadful again once I started the liothyronine I couldn't believe the difference to my mood and well being. I also was diagnosed with a b12 def last year. B12 was 151, was clear for antibodies... Doctor retested by b12 was over 2000 so they took it off me. I've been pushing to get injections back and I've been clear of b12 supplements since the summer. I felt as though they have given me a false reading. Has anyone ever been in a similar position or any advise? The last thyroid blood test I waited and took my medication after the blood test, am I still right to too this? Incase of a reduction? Many thanks

28 Replies

The following is a link and read Clutter's response.


When you post results you need to also add the ranges - the reason being that labs may have different machines so ranges may be different.

When you have blood tests for thyroid hormones, it has to be at the very earliest. You have to fast (You can drink water) and also allow a 24 hour gap between your last dose and the blood test and take it afterwards. This prevents your result being skewed and your dose being adjusted unnecessarily and I think you followed this for your last test.

Always get a print-out of your results with the ranges as members cannot respond without the ranges.

Ask GP to test TSH, T4, T3, Free T4, Free T3 and thyroid antibodies. If he or lab will not do so because your other results are in the normal range, you can get those not tested from one of our private labs. You should also have B12, Vit D, iron, ferritin and folate if you've not had all of them tested recently.

Re your last B12 result, usually excess B12 is excreted in urine. Could it be that you had your dose just before your test?

Kla88 in reply to shaws

Thank you for your reply shaws. The range is tsh 0.86 (0.3-4.2) and free t4 12.7 (12-22)

I hadn't taken any b12 for few weeks prior to b12 test, I know this should be 4 months but that's all the time I had at that stage.

I've not had b12 tested since April but will do again when surgery opens. My vit D and iron were OK ferritin seems to stick around 51 ( not sure of ranges to hand ) thank you

shawsAdministrator in reply to Kla88

FT4 is too low, being at the bottom of the range, whereas nearer the upper level would be best. Also if FT4 is low, usually Free T3 will be also and it is T3 which is the only active thyroid hormone required in our millions of receptor cells. Re B12, we aim for a result of around 1,000 (most top of ranges in some labs is around 600).

Hi - first of congratulations on your pregnancy. I'm certainly not an expert but I have researched the subject of pregnancy with hypothyroidism as I was considering IVF (not anymore as too ill). So here goes....

I do know that you have to have a low TSH level to conceive and for the pregnancy to go full term and also for the health of the baby. Your TSH level looks pretty good but without the reference ranges it's hard to know if the T4 level is good.

Also you need to keep an eye on your TSH levels throughout the pregnancy as apparently you can need higher doses of levothyroxine to keep the TSH low whilst pregnant and the baby relies on your thyroid hormone for the first trimester at least.

My endo told me that he didn't want me taking T3 while pregnant - that might be just him but I would check with that with other members - maybe make a new post - IS IT SAFE TO TAKE T3 WHILE PREGNANT?

I'm a little bit confused - are you saying that you feel worse after starting the T3 or that you are feeling better?

Re: the B12 - I have heard that you can get false high results once you are supplementing but again I'm not an expert.

Hope this helps....

Kla88 in reply to Maxxxx

Hi thanks for replying to me,

I seen the endo in October before I became pregnant and found the t3 great and really changed my mood or depression etc.

I had a blood test done the week after I conceived to check on the dosing on the t3 , I did not know I was pregnant at this stage.

Those previous results are from that test.

In October in my first meeting with the endo I told him I wanted to have another child and he said the t3 was safe for pregnancy. I believe the t3 helped me to become pregnant. I had a test done previous and my testosterone was very high... Seems the right dose has brought it down.

My endo wasn't concerned about my dose at 4 weeks - the previous test I had done and just said to Come back in 4-6 weeks.

This past few weeks I've just been feeling rough again and was just wondering is this normal with hypo, feels like I'm needing an increase and not due another blood test for 2 weeks.

Thank you for ur advice

Maxxxx in reply to Kla88

So pleased for you that you are pregnant but sorry you're not feeling well. The first couple of months can be trying even without thyroid problems.

Are you gluten free? I became gluten free about 18 months ago but decided to cheat about a month ago while I was in France. I just felt awful for a few days after that and co-incidentally I took a blood test and my antibodies were sky high so I truly believe that going strictly gluten free is essential in hypothyroidism even if you are not coeliac.

I know that your antibodies are not high but I still think that going gluten free can make you feel better.

Kla88 in reply to Maxxxx

I did try to go gluten free I found it so difficult but I'm gonna try again thank you

shawsAdministrator in reply to Kla88

When we get symptoms appearing again it is assumed your body needs an increase in dose so a blood test is due.

Kla88 in reply to shaws

Yes that's what it feels like to me! Thank you

Saya85 in reply to Kla88

Hi kla88,

Congratulations on your pregnancy.

As mentioned above and previous Comments thyroid control in pregnancy is crucial especially in first trimester. It is often routine practice to increase dose by 25 or even 50mcg. Yes your results for tsh were low but free t4 was too much on the lower side.

If you’re supplementing with t3 that may be making up for it sligjtly but as you said you were only week 1 into pregnancy! I would definitely have a blood test done again as soon as you can.

The 6 week rule for repeat testing is usually because it takes this long for medication dosages to take effect; it doesn’t necessarily apply when there is a baby growing in you who is effectively using up your thyroid hormones. If you’re getting symptoms again that’s definitely more than enough reason to test again.

P.s you say you were clear for antibodies so if not autoimmune thyroiditis I’m not sure going strictly gluten free will help you much unless you are at risk of triggering autoimmunity (family history of hypothyroidism )

And I would definitely have b12 and all the other vitamins tested again in the next few weeks

Good luck

Kla88 in reply to Saya85

Thank you for replying, yes in on 10 liothyronine and 75 levo.

I do have raised antibodies I do have hashimotos but I'm clear for Celiac.

Would the t3 be the reason for my t4 being lower? This is the lowest my t4 has been wile medicated.????

I'm going to book in and get the tests done as quick as possible. Thank you

shawsAdministrator in reply to Kla88

I am not medically qualified but my answer would be yes T4 would be lower if adding in T3.

The blood tests were introduced along with levothyroxine T4 only.

Before that everyone was prescribed NDT (natural dessicated thyroid hormones) and no bloods tests were available. It was gradually increased until we were symptom-free (as far as I am aware).

Levothyroxine is T4 only and converts to T3. T3 is the Active thyroid hormone required in all of our T3 receptor cells. T4 is inactive. Therefore if T3 is added the T4 will be lower.

The best way to judge if a dose is suitable for the person (no matter what form of thyroid hormone replacement someone takes) is how they feel i.e. symptom-free and well.

Kla88 in reply to shaws

Thank you Shaws. I'm starting to understand better why my t4 is at lower end of the scale.

shawsAdministrator in reply to Kla88

It is a big learning curve for us, the patient, as doctors don't appear to be knowledgeable except to look at the TSH. You can tick off the symptoms below and you will be surprised how many there are:-


Kla88 in reply to shaws

Thank you

Saya85 in reply to Kla88


Yes possibly the t3 supplementation could be causing the low t4. Usually you have to have a normal t4 range for it to be converted to enough t3... but if you’re supplementing with t3, the t4 almost becomes irrelevant.

In your case your t3 levels is probably more crucial and may need to be increased in pregnancy. They may adjust for both t4/t3 accordingly.

If you have hashimotos, then yes GF should help as does selenium supplementation at 200mcg. However discuss this with endo as I’m not sure if selenium has any impact on pregnancy.

I’m now more encouraged to get t3 supplementation myself as trying to conceive and t4 alone is doing little to help.

Good luck with your pregnancy x

Kla88 in reply to Saya85

Thank you so much for your knowledge Saya85. Yes I would push for it too if I was you & good luck too youx

Ah someone has got in before me! I read down your thread and couldn't understand if you were taking T3 why they hadn't done a FT3 result as once you are taking it it's the only result that is reliable and so needed. I had my family before I was diagnosed but from reading other posts I've seen some hospitals have dedicated midwives to monitor hypo mums and I also suspect many pregnant mums are told to stop T3 because the doctors know nothing about it rather than the fact it's harmful! How can it be when we are replacing what our body is no longer good at doing!

So congratulations! Keep posting so that others who have experienced this can help through experience. If you have any concerns then keep asking questions at the hospital. They are very good at throwing things at you without taking time to properly explain what it means for the baby. I imagine that mostly it isn't a problem but they don't seem to think that we need to be told that.

Kla88 in reply to silverfox7

My hospital only tests tsh and t4 when I asked the endo about it at very start he said he would go by how I feel.. So we will see if he keeps true to his word. Thank you for replying and your advice.

shawsAdministrator in reply to Kla88

They only test TSH and T4 as the assumption is that we are all taking levothyroxine.

On this forum that is not true as many have to add T3 or take NDT or T3 only in order to recover.

It's a pity that the professionals seem to be unaware of this fact and few will prescribe anything but levothyroxine and patient may remain unwell.

Congratulations, Kla88!

TSH of newly pregnant women is recommended in the low-normal range 0.4 - 2.5. Levothyroxine dose is usually increased by 30-50% when pregnancy is confirmed to ensure good foetal developement. cks.nice.org.uk/hypothyroid...

BTA doesn't support use of T3 during pregnancy so your endo may want to withdraw T3 until after delivery.

Management of primary hypothyroidism: statement by the British Thyroid Association Executive Committee

13. The serum TSH reference range in pregnancy is 0·4–2·5 mU/l in the first trimester and 0·4–3·0 mU/l in the second and third trimesters or should be based on the trimester-specific reference range for the population if available. These reference ranges should be achieved where possible with appropriate doses of L-T4 preconception and most importantly in the first trimester (1/++0). L-T4/L-T3 combination therapy is not recommended in pregnancy (1/+00).


Kla88 in reply to Clutter

Thank you Clutter

Oh god really I was under the impression that I would be able to continue thank you for preparing me incase of the withdrawal.

In my case the t3 helped me to conceive I had been told I likely had pcos due to high testosterone within a week of starting liothyronine my hormonal acne cleared up.

I don't know maybe my body needs it ahh hoping I can continue I've seen a few women on t3 through pregnancy but I'm aware that there isn't much research and it goes against the grain.

Thank you so much for ur advice

Clutter in reply to Kla88


I'm just warning you your endo may want you to switch but can't force you to. There are women who have taken T3 in addition to Levothyroxine during pregnancy and I believe Rhsana took T3 only during pregnancy and recently delivered a healthy baby.

Kla88 in reply to Clutter

Thank you clutter I appreciate it

Congratulations! Your story sounds similar to mine in that I just started T3 and got pregnant. It helped me a lot, but then I didn't feel so great. Currently 10 weeks and feeling bad, but got my bloods tested via blue horizon (so can get a complete picture). My results are OK - it's just general pregnancy making me feel this way! Having to accept I just need more sleep right now. However, I'm going to keep testing throughout to make sure I can up my doses as soon as necessary, as the Drs are not great at monitoring in line with the NICE guidelines etc. I also truly think I wouldn't have conceived without the T3.

Hi thank you so much

Is your t3 prescribed by nhs or do you self medicate. It's bad when we know more than the doctors.

It's prescribed but with a private endo. I've got appointment with him soon for monitoring, but I'll have latest blood results ready 😊 I'm making sure to take dilate (not folic acid) as I've mthfr mutation, methyl b12 and loads of vit d. I'm taking 6000 iu and think I need to up it as still not quite where I should be.

Sorry folate not dilate - auto correct

You may also like...