Thyroid UK
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Hypothyroidism linked to miscarriage??

Hi, I'm new this but really hoping someone can help. I have just suffered a miscarriage at 9 weeks and 5 days pregnant and I'm concerned it was due to my underactive thyroid. I'm looking for information so this doesn't happen the next time we get pregnant. I have been on 125 micrograms of levothyroxine for a few years with no real problems. After telling the midwife at my doctors I was pregnant I expected my meds would go up but at 8 weeks still nothing. I was suffering badly from feeling cold, constipated and exhausted but this could just have been pregnancy symptoms. I called and persuaded them to take bloods and then they put me up to 150 micrograms. I'm concerned now that the time of not being on the right dosage meant my baby was not growing correctly leading to the miscarriage. I'm not looking to blame someone, I just need to know what I should do for the next time I get pregnant. Please help x

6 Replies

Sorry you suffered a miscarriage. Lots of good info on this site including guidelines for TSH levels. PR

PS One other site with a lot of good health info for women.


Yes, I'm afraid there is a link. Sorry for your loss xx

As PR4NOW has said, Hypothyroidmom is a good place to start. Maybe start here:

According to the Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease during Pregnancy and Postpartum:

RECOMMENDATION 2 – Trimester-specific reference ranges for TSH are recommended: first trimester, 0.1–2.5 mIU/L; second trimester, 0.2–3.0 mIU/L; third trimester, 0.3–3.0 mIU/L.

RECOMMENDATION 16 – In pregnant patients with treated hypothyroidism, maternal serum TSH should be monitored approximately every 4 weeks during the first half of pregnancy because further dose adjustments are often required.

RECOMMENDATION 17 – In pregnant patients with treated hypothyroidism, maternal TSH should be checked at least once between 26 and 32 weeks gestation.


Click on the relevant grey and blue tabs on the left side of the screen on this page :

The link is to the NICE Clinical Knowledge Summaries for Hypothyroidism, and they essentially form guidelines that your GP should be following under various different circumstances, including pre-conception and pregnancy. Read them very, very carefully, make sure you understand what your GP should be doing, and make sure that your GP sticks to the guidelines in future.

For someone with overt hypothyroidism you should have been given an extra 25mcg - 50mcg of levothyroxine per day as soon as your pregnancy was confirmed. It is not necessary for the doctor to wait for the results of tests before prescribing the extra levo, it has to happen immediately on confirmation - it really is that important.

Good luck for any future pregnancy. :)


Thank you all for your replies. Its breaking my heart to know that potentially something could have been done to prevent my miscarriage from happening! But also good now that I feel more informed to go back to the doctors and ensure I'm given better care to get pregnant again. Unfortunately I've always relied on doctors but maybe its time I became more knowledgeable about my underactive thyroid. Thanks guys x

1 like

I'm sorry you lost your baby. We should rely on doctors/midwives to know about thyroid gland conditions, we haven't studied in medical school and have to find out the hard way ourselves which is ridiculous. The medical profession seem totally ignorant of how necessary medication is for the thyroid gland and for our health.


I am so sorry for your loss. Please be aware that the risk of miscarriage at 10- 12 weeks and at 16-18 weeks are actually quite high for all women for many reasons so may be nothing to do with a thyroid condition. I lost a baby at 17 weeks and no cause was identified . I have since been diagnosed with Hypothyroidism and certainly had the symptoms at the time of my pregnancy. I went on to have an other baby and whilst I was very stressed in the early stages my Midwife was great. You may never have a definitive cause for your loss but being well informed might help your level of future care. Best wishes.


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