Hashimoto’s Disease: The Danger of Thyroid Antibodies and Pregnancy

Hashimoto's Disease: The Danger of Thyroid Antibodies and Pregnancy

In 1990, a significant correlation between high levels of thyroid antibodies and an increased rate of miscarriage was first reported in the scientific literature.[1] Where are we at a generation later?[2] Despite the 20 years of compelling research confirming and expanding upon the initial finding, many doctors do not test a pregnant woman for thyroid antibodies, and few patients know to ask for proper testing.

Hashimoto’s disease is an autoimmune condition in which the body attacks and destroys its own thyroid gland. In a healthy immune system, antibodies act as the body’s army to detect and destroy invaders not normally present in the body, such as bacteria, viruses, fungi, and parasites. In the case of Hashimoto’s disease, a defective immune system wreaks havoc on the body by directing antibodies against its own thyroid gland as if it is a foreign invader. Although Hashimoto’s is the number one cause of hypothyroidism in the United States, it is a tragically overlooked disease in the health care system.

You may have Hashimoto’s disease and not even know it.

According to the American Thyroid Association, 10 to 20% of all pregnant women in the first trimester of pregnancy are positive for Hashimoto’s antibodies, but they are euthyroid. Euthyroid means they have normal thyroid functioning based on their TSH (thyroid stimulating hormone) level, the most common measurement of thyroid function. Their thyroid function in early pregnancy appears to be normal and they may even feel well, all the while their body is silently attacking and destroying their own thyroid gland. A significant percentage of these women will however develop a TSH above the trimester-specific pregnancy reference range by the third trimester, endangering the life of their fetus.[3]

 By testing TSH alone, thyroid antibodies in Hashimoto’s may be missed, and your doctor may have no idea your baby is at risk.

The number one issue is that many traditional doctors do NOT test for thyroid antibodies. In mainstream medicine TSH rules, leaving millions of Hashimoto’s patients around the world undiagnosed and untreated. You must be an advocate for yourself and insist on the following two thyroid antibody tests.

Thyroid Peroxidase Antibodies (TPOAb)
Thyroglobulin Antibodies (TgAb)

Thyroid Antibodies and Miscarriage

Researchers in a 2011 study published in the British Medical Journal conducted a systematic review of 31 studies involving 12,126 women that assessed the association between thyroid autoantibodies and miscarriage. Of the 31 studies, 28 separate studies found thyroid antibodies increased the risk of miscarriage by 290%. According to researchers:[4]

In the developed world, thyroid autoimmunity is the main cause of hypothyroidism, which itself results in poor obstetric outcomes. Even in women with biochemically normal thyroid function, studies have reported an association between the presence of thyroid autoantibodies, particularly thyroid peroxidase antibodies and adverse pregnancy outcomes, including miscarriage, preterm birth, and adverse neurodevelopmental sequelae in children.

The Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease during Pregnancy and Postpartum recommend:[5]

Women with Hashimoto’s who are not receiving thyroid treatment require monitoring for hypothyroidism during pregnancy. TSH should be evaluated every 4 weeks during the first half of pregnancy and at least once between 26 and 32 weeks gestation. TSH levels above the trimester-specific pregnancy reference range should be treated (first trimester, 0.1-2.5 mIU/L; second trimester, 0.2-3.0 mIU/L; third trimester, 0.3-3.0 mIU/L).

According to Dr. David Clark, DC Functional Neurologist:[6]

  1. As a mother, if you have TPO antibodies that means you have a real risk for becoming hypothyroid. Hypothyroidism itself can cause miscarriages and premature birth.
  2. If you have TPO antibodies, you have ONE autoimmune disorder, and your immune system is attacking ONE tissue…it can now easily attack something else, like a developing fetus.

The lack of awareness about Hashimoto’s disease is pervasive. Do not assume your doctor is aware of the dangers of Hashimoto’s in pregnancy. Take charge of your thyroid health and insist on thyroid antibody testing.

I learned the hard way that when it comes to thyroid disease in pregnancy we must be our own advocates. Not all doctors are informed enough about proper testing and treatment of women with thyroid issues during pregnancy. Under my award-winning New York City doctor’s care, my TSH soared far above the recommended range for pregnancy and I miscarried my child. I can’t go back no matter how much I wish and change things for my baby but what I can do is make sure this never happens again to another baby.


1. Stagnaro-Green, A., Roman, S.H., Cobin, R.H., el-Harazy, E., Alvarez-Marfany, M., Davies, T.F. Detection of at-risk pregnancy by means of highly sensitive assays for thyroid autoantibodies. Journal of the American Medical Association 1990 Sep 19;264(11):1422-5.

2. Stagnaro-Green, A. Thyroid Antibodies and Miscarriage Where Are We at a Generation Later? Journal of Thyroid Research 2011 May 12;2011:841949.

3. Stagnaro-Green, A., Abalovich, M., Alexander, E., Azizi, F., Mestman, J., Negro, R., Nixon, A., Pearce, E.N., Soldin, O.P., Sullivan, S., and Wiersinga, W. Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and Postpartum. Retrieved from http://thyroidguidelines.net/pregnancy.

4. Thangaratinam, S., Tan, A., Knox, E., Kilby, M.D., Franklyn, J., Coomarasamy, A. Association between thyroid autoantibodies and miscarriage and preterm birth: meta-analysis of evidence. British Medical Journal 2011;342:d2616.

5. Stagnaro-Green, A., Abalovich, M., Alexander, E., Azizi, F., Mestman, J., Negro, R., Nixon, A., Pearce, E.N., Soldin, O.P., Sullivan, S., and Wiersinga, W. Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and Postpartum. Retrieved from http://thyroidguidelines.net/pregnancy.

6. Dr. David Clark, DC. Thyroid Antibodies and Risk of Miscarriage, Premature Birth. Retrieved from DallasThyroidDoctor.com: http://drclark.typepad.com/dr_david_clark/2011/11/thyroid-antibodies-and-risk-of-miscarriage-premature-birth.html.

Take Back Your Thyroid Health! Sign up and never miss a post - it's FREE

I appreciate every share! Thank you.

About Dana Trentini

Dana Trentini founded Hypothyroid Mom October 2012 in memory of the unborn baby she lost to hypothyroidism. This is for informational purposes only and should not be considered a substitute for consulting your physician regarding medical advice pertaining to your health. Hypothyroid Mom includes affiliate links including the Amazon Services LLC Associates Program.


  1. I had three miscarriages that were caused by this. All of my miscarriages were the same – the fetus died at 9 1/2 weeks. I did have my thyroid checked by they completely missed this because of course my thyroid results fell into the “normal range”. No one seemed to care that I had a goiter. I finally went to an endocrinologist and they diagnosed me with Hashimoto’s. If I had not started taking thyroid medication, I would have had another miscarriage and would not have had my daughter. Now I tell all young women that if they have more than two miscarriages – go get your thyroid checked and get your antibodies checked – you may have Hashimoto’s Thyroiditis and save yourself a lot of heartache.

    • Sara Crowder says

      Did you find out you had Hashimotos during your pregnancy? If so, how far along we’re you? I’m a little concerned. I found out I have Sub Clinal Hypothyroidism (TSH normal) and Hashimotos and am now 5 weeks pregnant. My doctor just told me to take selenium and Vitamin D to see if that would bring it down but I don’t know if that was successful yet. Having my antibodies tested again Tuesday…..just wondering what my chances are of a healthy pregnancy at this point.

      • I found out I have Hashimotos when my baby died at 13 weeks 5 days July 19,2019. (Baby was healthy with a very strong heart beat on a Friday 13 weeks 2 days, went in Monday July 22,2019 to meet my Dr and no heartbeat was detected,3 days after I had heard them last.) If you feel like something is wrong trust your instincts, and see a Dr. Now I’m on thyroid medication to increase my hormone levels so when I do decide to try again I have a decreased chance of miscarriage. When I had the anti bodies checked and I’m at like 396, when I was first tested I was at 374. A little discouraged, but I’m not liking my Dr. So I am going to go to another one that will listen to my concerns and help me have a healthy baby. I think you may need to get a second opinion for treatment. Have a blessed day and a healthy baby.

    • What can you do if you have antibodies? I am positive for both of them and had 4 miscarriages:(

  2. You speak about the sickness but you did not mention if there is any cure about it.

  3. Dr. Few. J. Krzykwa says

    Find the cause by having an LRA Elisa/ACT Biotech Blood test. Call the lab in Sterling , VA.

  4. Is therr s study about Hashimoto disease in older prople?

  5. Natasha Aston-Hill says

    I am currently 6 months pregnant. I had developed Hasimotos after giving birth to my son but I was able to treat it naturally. I then had 2 miscarriages in between him and this pregnancy. So far everything seems to be fine except my TPO level is around 1000. Which is bad. Do you have any recommendations that won’t take up much time which could help me get those levels down without harming my baby? Thank you so much!

  6. Do you have any resources or studies that address taking NDT during pregnancy? I’m hoping to find something concrete to show my doc who is pressuring me to switch to solely t4.

  7. Hello, your posts have been very helpful. I recently lost my baby at 6 weeks and found out at 8 weeks.
    This miscarriage has been the difficult time in my life. I am really concerned abt my next pregnancy, I want to try my best to make it a successful one.
    These were the thyroid levels that were tested for me and the results. Please let me know if you see anything wrong, it can help me pinpoint what the cause was!
    TSH at week 4 was 2.25
    TSH at week 6 was 3.23
    TPO was 88.3 iu/ml
    Free T4 was 1.6
    Thyroglobulin says <1.0 ng/ml
    Thyroglobulin antibody says positive

    PLEASE please let me know if these look like results that might cause a miscarriage. I am praying it was just a natural one, but if it is my thyroid I need to know soon before my next pregnancy.

    Thank you!!!

  8. Hi, I am pregnant with my second child but first time pregnant with Hashimoto. I started (not pregnant) with a TSH at 215 and got pregnant with a TSH at 12.59 and my NP who also has Hashimotos increased my dosage. I just got my Lab Results and my TSH dropped to 5 but my TPO antibodies increased from >600 to >900. My doctor’s office is closed…should I call him still or wait until Monday? I follow the paleo diet and take a prenatal, vitamin b6 (for nausea) and selenium and magnesium.

    I am just honestly worried-I still have the pregnancy symptoms so I don’t feel a miscarriage at all but it is still all so new to me

    • Hi Julie, Congratulations on your pregnancy. Be sure to have thyroid testing frequently and in many cases including my pregnancy several increases of dosage in thyroid medication may be needed especially in the first trimester. Please show your doctor the Endocrine Society guidelines for pregnancy. Good to have you at Hypothyroid Mom.

      Recommendation 1.2.3. If hypothyroidism has been diagnosed before pregnancy, we recommend adjustment of the preconception T4 dose to reach before pregnancy a TSH level not higher than 2.5 mIU/liter.


  9. But even if your Thyroid Antibody is high, taking thyroid medicine ( to regulate TSH) does not regulate the antibody level right? So how can we do anything to protect our unborn children from our antibodies.

  10. If my TSH is in range (1.5) but my TPO is 557 and my TG ab is 215 how worried do I need to be? I’m going strict AIP but still so worried.

  11. I just found out I am pregnant with my 3rd child. 1st born 4 weeks early. 2nd fine but with slight emotional imbalance. 3rd I am 5 weeks I was just diagnosied with Hashimoto with a thyroid antibody count of over a thousand. Not sure how far over as the test doesn’t go any higher. With eating a paleo diet I was able to drop it down to 600 however 60 is high I’m not sure what I should do. I am scared to lose my baby. Any advice or suggestions

    • Hi Ashley, Congratulations on your pregnancy. There is much that I have to say about a healthy pregnancy with thyroid disease that I wrote a book about it “Your Healthy Pregnancy with Thyroid Disease” but one thing to start with is to be sure to have full thyroid testing asap in your pregnancy. When a woman is hypothyroid, it is common for her TSH to rise early in pregnancy and to require increases in dosage of thyroid medication. I personally had 2 increases in my thyroid meds during my first trimester. The Endocrine Society recommends a TSH less than 2.5 in the first trimester. So the first step is calling your doctor for testing. All the best for you and your baby. Here is the Endocrine Society guidelines to show your doctor.


  12. Ashley Brandt says

    I just found out I am pregnant with my 3rd child. 1st born 4 weeks early. 2nd fine but with slight emotional imbalance. 3rd I am 5 weeks I was just diagnosied with Hashimoto with a thyroid antibody count of over a thousand. Not sure how far over as the test doesn’t go any higher. With eating a paleo diet I was able to drop it down to 600 however 60 is high I’m not sure what I should do. I am scared to lose my baby. Any advice or suggestions

  13. So how do you inhibit these antibodies while pregnant? My wife has hashimotos and we had one totally healthy pregnancy with her on her meds and have had 4 miscarriages since then and test wise they cant figure out why and they are happening progressively sooner. The first one was 9 then 8 then 7 now this ones at 6. They did testing and found no genetic abnormalities.

    • I feel for you guys. I had multiple miscarriages between 1st and 2nd child. Recently, I was tested for the MTHFR gene and tested positive. The gene variant c677t is linked to multiple miscarriages. Does your wife have any family members that have experienced blood clots? That is a red flag. The loss of pregnancy is due to homocysteine imbalance and body’s inability to process methylfolate. I have been put on methylated B-12 because no matter how much regualar B-12 I took, my levels stayed low. It’s just a thought, but you might want to get screened for it. There are things you can do to help bring your body back into balance.

  14. In 2009 I delivered my son one month early. Once he was born they told me that my antibodies were attacking his platelets. He almost did not making it after platelet transfusions and trying a medicine the doctor was hoping would help. Thankfully it did. Since that time I have been struggling and feeling worse and worse. They diagnosed me with Hashimoto and fibromyalgia. It’s so frustrated because they won’t prescribe anything to help and the many times I’ve brought up this experience when I gave birth to my son, they know nothing about it and no connection is triggered in their mind. 🙁 I just wish there was more help and easily accessible to find someone to help.

    • Hi Kim, How scary that must have been for you when your son was going through all that. I too wish there was more awareness in the medical world about antibodies and the potential dangers in pregnancy and these dangers were the real reason I created Hypothyroid Mom. I miscarried my baby unnecessarily from inadequately treated hypothyroidism. Pregnancy and postpartum are common times for someone to develop a new thyroid condition or worsen an existing one as happened to me with every pregnancy. It sounds like you are not being well treated for your Hashimoto’s. I recommend this book “Hashimoto’s Protocol” for you to read because there is much you can do on your own to make a significant difference: https://amzn.to/2HqaNgF

  15. Hi, I have normal TSH and T3 & T 4 but with higher than normal antibodies. I am wanting to fall pregnant next year. Could you write an article on the dangers of antibodies alone? Without thyroiditis, even if I’m going to develop that later on in life. My GP told me that these antibodies ‘do nothing’ but that doesn’t seem right?

    • Hi Ana,

      I am curious if you ever found the answer to your question. I am currently pregnant with my 3rd baby and all my levels are normal but I have one antibody slightly out of range. See below.
      THYROGLOBULIN ANTIBODY 21.0 IU/mL 0.0 – 0.9 IU/mL

      My thyroid condition started after my 2nd baby 2 years ago. I was able to get my levels under control with very little medication and diet.

Speak Your Mind