1. Health

Can Hypothyroidism Cause Miscarriage?


Updated January 15, 2009


Research is mixed on the exact relationship between undiagnosed hypothyroidism and miscarriage.

Photo © Dougal Waters / Getty Images
Question: Can Hypothyroidism Cause Miscarriage?

The thyroid gland plays an important role in the body's metabolic and hormone balance, and when something's off with the thyroid, there's a good chance the rest of the body will be affected.


Research suggests that having an underactive thyroid may, indeed, be linked with some types of pregnancy loss, although the exact nature and circumstances of the link are not universally accepted.

A 2000 study found that women with untreated thyroid deficiency had a significantly increased risk of second-trimester miscarriage or stillbirth. A different study in 2005 found that subclinical hypothyroidism could mean an increased risk of placental abruption and of preterm delivery, both of which can result in later pregnancy loss.

Evidence is less clear about a link between hypothyroidism and first-trimester miscarriage; some studies suggest that thyroid autoimmunity may be linked to first-trimester miscarriage, but other studies contradict the link and the matter is still up for debate.

Symptoms of hypothyroidism include inappropriate weight gain, inability to lose weight, feeling cold often, fatigue, coarse hair and other problems. If you are concerned that you may have hypothyroidism, ask your doctor about screening.


Allan, W.C., J.E. Haddow, G.E. Palomaki, J.R. Williams, M.L. Mitchell, R.J. Hermos, J.D. Faix, R.Z. Klein, "Maternal thyroid deficiency and pregnancy complications: implications for population screening." J Med Screen 2000. Accessed 8 May 2008.

Casey, Brian M., Jodi S. Dashe, C. Edward Wells, Donald D. McIntire, William Byrd, Kenneth J. Leveno, and F. Gary Cunningham, "Subclinical Hypothyroidism and Pregnancy Outcomes." Obstetrics & Gynecology 2005. Accessed 8 May 2008.

Sieiro, Netto L., C. Medina Coeli, E. Micmacher, S. Mamede Da Costa, L. Nazar, D. Galvao, A. Buescu, and M. Vaisman, "Influence of thyroid autoimmunity and maternal age on the risk of miscarriage." Am J Reprod Immunol Nov 2004. Accessed 8 May 2008.

  1. About.com
  2. Health
  3. Miscarriage/Pregnancy Loss
  4. Causes
  5. Two or More Miscarriages
  6. Endocrine Factors
  7. Hypothyroidism and Miscarriage - Suspected Link Between Hypothyroidism and Miscarriage

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.