Thyroid UK

Hashimotos and pregnant. Facts please!!

After my son was born in 2013 I was diagnosed with hyperthyroidism, that very quickly turned under active. I was prescribed 50/75mcg thyroxine alternating daily, and my levels have been stable since.

I am now in the second trimester of pregnancy. At 4 weeks, my dose was upped to 75mcg daily And again my levels have been within a good range. When I saw my consultant last week my tsh was 1.38 and free t4 was 15.8. However I've now had two lots of antibody tests and in the doctor's words they showed "a very high level". It has now been suggested that I have Hashimotos. I am to undergo further tsh receptor antibody tests and I have been told these can transfer to baby, causing it to suffer thyroid disease.

I just want to know what this means for me and baby. I want the facts. Please don't water it down!!

How likely is it the antibodies will pass to my baby?

What does having hypothyroidism mean for Myself and baby while pregnant if my levels are stable and monitored?

What pregnancy complications could hashimotos bring on And how Likely is this?

Could my baby be born with hyper/hypothyroid or hashimotos and could this mean it suffers with respiratory and heart problems or developmental delay at birth,the same as if the condition was not treated?

Thanks in advance for your help

5 Replies

Welcome to the forum, Hugs84 and congratulations on your pregnancy.

Hashimoto's will have been developing for years before you became hypothyroid. It's not uncommon to experience transient hyperthyroidism before becoming hypothyroid and your first pregnancy may have been the trigger. Hashimoto's can be genetically passed on and can cross the placenta barrier causing congenital hypothyroidism but it doesn't mean that either will happen. Babies are given a heel prick thyroid test to check for thyroid problems before they leave the hospital and if there is hypothyroidism will be prescribed Levothyroxine which will prevent any developmental impairment and symptoms.

As your TSH is low-normal there is little risk of miscarriage. Levothyroxine was increased during your first trimester to ensure good foetal development for the first 3 months when the foetus is entirely dependent on maternal thyroid hormone. After 3 months the baby will have developed his own thyroid gland.

Dana Trentini has an excellent website which she started after she miscarried due to undiagnosed hypothyroidism.


Thanks this is all very helpful x



I developed hypothyroidism during my last pregnancy. I wasn't checked for antibodies. My baby was born, she had the heel prick test and a separate more detailed thyroid test and she was fine. I had my antibodies checked a few months after she was born which confirmed I had Hashimotos disease, tpo in excess of 100 and thyroglobulin 700. Despite this my daughter was OK and she is now a healthy normal 5 year old. Try not to worry, but ensure you are closely monitored. Best wishes


Thank you!! x


The NHS test for congenital hypothyroidism at birth. It's unlikely that your baby will have any problems as your levels are well managed.

I also have hashimotos and high levels of antibodies. I was advised not to worry about the antibody levels too much.

About 10% of the population have thyroid antibodies. Not all will go on to have thyroid problems. About 3.5% of women of childbearing age have hypothyroidism according to NICE guidelines (which are basically instructions to the nhs on how to manage various conditions).

As long as your thyroid levels are normal you and your baby shouldn't have any problems. The doctors should test your levels regularly as wimen usually need a higher dose whilst pregnant.

Research says that outcomes are the same as people without thyroid problems as long as your levels are normal. There are lots of potential complications for people with unmanaged hypothyroidism but don't worry about that.

Relax and be happy. Research shows anxiety in mothers can affect babies so the best thing you can do right now is not worry and be happy!

Congratulations on your bump!

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