Pregnancy Complications of Hashimoto’s Thyroiditis

Hashimoto’s thyroiditis is a chronic inflammatory autoimmune disease where various antibodies are mistakenly directed against healthy thyroid tissue, resulting in a destruction of these cells and consequent reduction in thyroid hormone levels (hypothyroidism). Health Central states that women are roughly twenty times more likely than men to be diagnosed with this condition. Given the potential for complications during pregnancy and the prevalence of Hashimoto’s in the female population, it is important that these hypothyroid patients acquaint themselves with some of the more common problems surrounding childbirth.

What are the possible pregnancy complications from my Hashimoto’s disease?

When a woman carrying this diagnosis becomes pregnant, there are certain possible problems that may arise over the course of her pregnancy, particularly when she is without active treatment for the condition. Such problems may affect mother, fetus or both. Fortunately, careful compliance with medications and regular testing can significantly reduce the likelihood of such instances, but one must remain cognizant of such potentialities regardless.

Among the most common complications arising from overt hypothyroidism during pregnancy are preeclampsia/hypertension, placental rupture, preterm delivery with low birth weight, postpartum hemorrhage, and physical/neurological/psychological problems for the child. Indeed, as noted by the Mayo Clinic, “Babies born to women with untreated hypothyroidism due to Hashimoto’s disease may have a higher risk of birth defects than do babies born to healthy mothers.”

What complications might arise if my medication dose is too high or too low?

When thyroid medication (thyroxine) dosages are not adjusted properly, the resulting complications may be those of either hyperthyroidism (meds too high) or hypothyroidism (too low). So any complications seen in these circumstances would most likely be those of the respective thyroid state the patient finds herself in. For those on too little medication, these will include all of the scenarios mentioned above, while those on too much medication – and therefore thrown into a hyperthyroid state – are at increased risk for premature labor, miscarriage, stillbirth and heart failure, in addition to preeclampsia and low birth weight as above.

What if the initial onset of Hashimoto’s occurs during pregnancy, and my doctor checks my TSH, which is in a normal range for most labs (.5 – 6.0), but too high for an endocrinologist’s range (.3 – 3.0), and thus my hypothyroidism is undetected and untreated during pregnancy?

Virtually all women, including those without thyroid conditions, experience a mild hypothyroidism of pregnancy, driven by the increased maternal-fetal demand during this special state. Therefore, reduced hormone levels on their own without confirmation of antibodies are not necessarily abnormal over this period (though they should still be addressed and treated). That being said, there is a difference between this expected state and true hypothyroidism, of any variety, requiring additional attention. According to Medscape, “Patients who are diagnosed with Hashimoto thyroiditis or hypothyroidism from any cause during pregnancy should be started on a levothyroxine dose close to their replacement requirement, and the TSH level should be normalized as soon as possible. Untreated hypothyroidism carries increased maternal and fetal complications.”

The good news is that lab results falling within the old, but outside the new, parameters will mainly detect very mild and possibly asymptomatic (“sub-clinical”) disease, which as indicated above, can then be easily treated with medication to restore hormone levels to normal. This means that a patient who finds herself in this situation can be somewhat reassured that any undetected hypothyroidism will be mild enough so as to carry minimal risks to mother and baby. However, most ob/gyn or internal medicine practitioners who receive borderline lab results for pregnant women will refer the patient to an endocrinologist for further workup. This will certainly narrow the gap and reduce the instances of treatable disease going unnoticed, but any new symptoms during pregnancy should still always be reported to the treating physician immediately.

Questions for your doctor:

  • What other conditions must be ruled out to make this diagnosis? (i.e., what is the differential diagnosis?)
  • What lab tests do I need to have and when?
  • Is there anything else I should be doing, not doing, or taking (besides thyroxine) to help avoid complications?
  • How do you make the determination between normally reduced hormone levels of pregnancy and overt hypothyroidism?
  • Are there any additional potential complications not mentioned in this article?


About the Author
Dr. Rothbard is a professional medical writer and consultant based in New York City, specializing in medical education articles targeted at a variety of audiences, from children through clinicians.  After leaving medicine, he worked as a biology and medical science educator for several years, before deciding to pursue writing full-time.  He may be reached at [email protected].


This post contains opinions of the author. is not a medical practice and does not provide medical advice, diagnosis, or treatment.  It is your responsibility to seek diagnosis, treatment, and advice from qualified providers based on your condition and particular circumstances.  Camino Real Ventures, Inc., the company that makes available to you, does not endorse nor recommend any products, practices, treatment methods, tests, physicians, service providers, procedures, clinical trials, opinions or information available on this website.  Your use of the website is subject to our Terms of Use and Privacy Policy



  1. Women who lost their thyroid to thyroid cancer or as a result of RA treatment and want to get pregnant should know that it is possible to have children, however it is a high risk pregnancy. Thyroid hormone requirements increase about 30 to 50% during the first trimester in women who already had hypothyroidism before pregnancy and the dose of medication has to be adjusted accordingly. Tests are recommended every 4-6 weeks during the pregnancy to monitor thyroid hormone levels. Low thyroid levels can affect the fetus and result in preterm delivery and lower IQ of the child.

  2. Most doctors treat Hashimoto’s disease as a Thyroid disorder. It is in fact an auto immune disease that affects/attacks the thyroid therefore you notice the symptoms. BUT the thyroid isn’t the only organ affected/attacked.

    I had tried unsuccessfully to get pregnant for 13 years. 4 rounds of IVF – never testing pregnant. All of the IVF specialists considered it unexplained infertility… because they only check the a limited list of potential fertility problems. I was FINALLY referred to Dr. Sami David NYC an infertility endocrinologist. Amazing!! 1st appointment we discussed that I had Hashimoto’s disease & he said we need to test your level of natural killer cells (huh) no one had ever mentioned that before. I was tested & they were off the charts, apparently not uncommon. Essentially when you have an auto immune disease your natural killer cells attack what they consider a foreign invader. When they are elevated they attack everything.. SO I would conceive but the natural killer cells would attack the embryo so by the time you take a pregnancy test it is mon viable.

    The solution was quite simple – there is a soy based product that is given thru IV every 3 weeks to suppress your immune system. I eliminated all gluten so my digestive system worked properly (most of your usable T3 is produced in your intestines) & they switched my medication from a high dose of Synthroid to a lower dose & added a small dose if Cytomel every other day.

    We waited 5 months to make sure my T3free, T4free & TSH were finally in a good place & I got pregnant in the 1st round of IVF. Did i also mention i was 45 yrs old. They continue the soy based Infusions until 3 months into the pregnancy – then the baby has it’s own immune system.

    My son just turned 1 two days ago & he’s happy & healthy. Just want to give hope to other woman who have not been able to have a baby. Most doctors won’t pursue this so you have to insist that they do the test. There is another specialist near San Francisco that also works to find infertility problems. Helped 2 friends finally get pregnant in their 40’s.

    I just hope this helps someone so they don’t have to wait 13 years & experience so much heart ache!!

    • I am encouraged and practically in tears hearing your story. I lost a baby earlier this year and haven’t been able to conceive as a result of my thyroid imbalance. I am about to turn 40 in just one month and I currently live in San Francisco. I would love to know the name of the doctor that you said you friends went to see in the area.

      • Katie Cleary says:

        Hi VB,
        I contacted Monica to make sure she knew about your comment (she didn’t, so thanks for helping me find a bug on the website) and she is out of the country right now. She will get the name of the doctor from her friends when she returns to the US in Jan, and will either send it to me or post it here – so hang in there and we are working on it! Happy New Year and thanks for your heartfelt comment – prayers and good thoughts for a great 2014.

        Take care,

      • Hello VB – I have emailed my friend in the Bay Area to get the info on the doctor that they used and will forward the info as soon as I receive it. Sorry I didn’t get back to you sooner, I never received your post.

    • Interesting since soy is toxic to those with Hashimoto’s and my body is highly sensitive (possibly allergic) to it, as a soy based diet is was triggered my diagnosis after my thyroid crashed and burned. Many Hashimoto’s patients have also found that the elimination of soy has helped them immensely. I would think a soy based medication would cause the opposite result.

      • yes Tracy this is what I’ve heard! My daughter has hashimoto and celiac disease. She is %100 paleo as a way of life. No dairy, no sugar, no soy, no corn or grain. Her hair grew back her skin is amazing and so is her mental and physical well being. Also check out all your meds! Many have gluten as does synthroid but not levothyroxcin.

    • Wow! This hit me really hard. I too have Hashimoto’s and have done 3 ivf’s and none took. I am now almost 43 and can’t imagine my life without children. We have been trying for 21 yrs and my dr always told me my hashimoto’s has nothing to do with me not being able to get pg but it does. After my last round which was over 5 yrs ago haven’t been to the dr since.
      I want to try one last time but so scared it won’t happen.

      • Katie Cleary says:

        Oh Elena,
        My heart broke reading your comment. I ache for all you have been through. I know no words suffice, but you’re in my prayers. Whatever path you take, all of us here are behind you and hope for the very best.

  3. Hello VB – The doctors name was Alan Beer – he has since passed away but his associates are still running the The Alan E. Beer Center for Reproductive Immunology & Genetics in Los Gatos, California.


  4. Hi there Dr. Sammi David is another highly recommended specialist, he co-wrote the book Making Babies and specializes in solving “unknown causes” for women struggling to successfully conceive and carry full term.

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