Over active thyroid and pregnancy

Hi all. This is my first post on here and was hoping for some advice. I have just found out I am 3 weeks + pregnant. We are very happy, albeit worried. I have been on 40mg of carbimozole since august last year and 5mg of bisprolol. I am really concerned that this may have affected baby's start in life. Looking at my dates I think I am most probably c. 4 weeks gone. I have spoken to my doc and if anything she has worried me more. She said I shouldn't stop taking my meds until told to do so. I have an appt with her this eve but could not help doing some research on net and am very worried as a result. Has anyone been pregnant whilst taking thyroid meds? If so what dose were you on and did you have any complications? If there's any info anyone can give me it would be greatly received. Many thanks x

6 Replies

  • It's important that your thyroid hormone levels are monitored during the early stages of pregnancy. You should continue with your medication and have it adjusted to keep your hormone levels stable, perhaps slightly higher during pregnancy. I believe the recommendation is to be under the care of an endocrinologist in this case rather than your GP. Given that you are already pregnant and seeing your doctor tonight ask for a referral but suggest in the meantime they telephone a local endocrinologist for advice on your immediate care. If they do not have recent blood test results for you they should arrange another blood test now. It should all be OK but they need to keep an eye on it and have expert opinion.

    I forgot to say that because you are on carbimozole they do need expert opinion, they may put you on a different medication or just make sure you are on a minimal dose. It is OK to be on carbimozole but the person prescribing do need to have a detailed knowledge of its use in pregnancy.


  • Thanks for your reply Jim. Really helpful. I do have an endo already but he only sees me every 6 months. I'm hoping my doc would have called him in between me speaking to her 2 days ago and my appt this eve. When I spoke to her I wasn't encouraged that everything would be ok hence why I am concerned.

    In terms of dosage, is 40mg high?

    It's good to know that carbimozole is ok to use in pregnancy. Tbh I have been feeling so much better these past couple of months so I'm hoping my levels are lower and meds can be reduced.

  • I don't know if 40mg of carbimazole is high or low, it would depend upon what your thyroid hormone levels are now. If you haven't had a recent thyroid blood test they need to do one very soon and also review your carbimazole. If you haven't got anywhere with your GP this evening I suggest you contact your endocrinologists office and ask for a quick appointment or a telephone consultation. It's probably all OK but Ithink you should get specialist advice soon, even if it's just a brief chat.


  • Hi Sally, I like you am hyper (albeit "under control") and I'm hoping to get pregnant this year. From what my endo has told me I think it's better to be on PTU whilst pregnant. You should definitely be monitored more closely by your endo and they can also screen the baby for antibodies if you have an autoimmune disease such as Graves. Take care x

  • Thanks for replies. Well the doc didn't really tell me anything new. Other than they prefer not to use carbimazole in early pregnancy but given I am c.6-8 weeks I have already gone past that point. My endo hasn't got back to her even though she has left several requests. I am getting blood tests done on Monday so hoping my levels are lower. My only concern is the baby and I just hope I haven't /meds haven't done any harm. I'm really worried.

  • Hi Sally, I have just seen your post. Like Charls28, my endo has also told me that if planning pregnancy, meds are to be changed to PTU.

    Can you call your endos secretary and get a message to your endo saying you are pregnant and still on 40mg carbi? X

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