Thyroid autoimmunity and miscarriage: a meta-analysis

Clin Endocrinol (Oxf). 2011 Apr;74(4):513-9. doi: 10.1111/j.1365-2265.2010.03974.x.


Objective: To investigate whether thyroid autoimmunity (TAI) is associated with increased risk of miscarriage in euthyroid women.

Methods: An electronic search was conducted using the databases Medline, PubMed, EMBASE and the Cochrane library, from inception to October 2010. A systematic review of the studies on the association between TAI and miscarriage was performed. The odd ratios of case-control studies and relative risks of cohort studies were pooled respectively. The software Review Manager (version 4.3.1) was applied for meta-analysis.

Results: The search strategy identified 53 potentially relevant publications, 22 of which were included in the meta-analysis. A clear association between thyroid autoimmunity and miscarriage was observed with a pooled odds ratio of 2·55 (95% CI 1·42-4·57, P=0·002) in eight case-control studies and a pooled relative risk of 2·31 (95% CI 1·90-2·82, P<0·000 01) in 14 cohort studies. Women with TAI were found to have slightly higher age [age difference, 1·29 years] (95% CI 0·43-2·16, P=0·003) and thyroid-stimulating hormone (TSH) levels [TSH difference, 0·61 mIU/l] (95% CI 0·51-0·71, P<0·000 01) compared with those without TAI.

Conclusion: Based on the currently available evidence, it appears that the presence of thyroid autoimmunity is associated with an increased risk of spontaneous miscarriage in euthyroid women.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Abortion, Spontaneous / epidemiology
  • Abortion, Spontaneous / etiology
  • Abortion, Spontaneous / immunology*
  • Adult
  • Age Distribution
  • Antiphospholipid Syndrome / complications
  • Antiphospholipid Syndrome / epidemiology
  • Antiphospholipid Syndrome / immunology
  • Autoimmunity / immunology*
  • Female
  • Humans
  • Mastocytosis, Systemic / complications
  • Mastocytosis, Systemic / epidemiology
  • Mastocytosis, Systemic / immunology
  • Pregnancy
  • Thyroid Gland / immunology*