Subclinical hypothyroidism and thyroid autoimmunity in women with infertility

Gynecol Endocrinol. 2007 May;23(5):279-83. doi: 10.1080/09513590701259542.


Objective: To determine the prevalence of different subclinical hypothyroidism (SH) grades and thyroid autoimmunity (TAI) in infertile women.

Design: Retrospective study. Setting. Endocrinology division of a public hospital in Argentina.

Patients: Group I comprised 244 women consulting on infertility (>1 year without pregnancy); Group C (controls) comprised 155 healthy women with confirmed fertility.

Intervention: Thyroid-stimulating hormone and thyroid peroxidase antibodies were measured in all patients, and a thyrotropin-releasing hormone (TRH) stimulation test was performed in 71 patients to diagnose SH grade 1. The pregnancy rate in hypothyroid women on levothyroxine treatment was also evaluated.

Results: SH was diagnosed in 13.9% of the patients in Group I and in 3.9% of Group C (p < 0.002). The TRH stimulation test was useful to detect SH grade 1 in 12.7% of the infertile patients. Patients with precocious ovarian failure, tubal disturbances and ovulatory dysfunction presented higher SH rates (40.0, 18.2 and 15.4%, respectively) than control patients (p < 0.0001, p < 0.002 and p < 0.003). No significant difference in TAI prevalence was shown in Group I relative to Group C. Pregnancy rate of 44.1% was achieved under levothyroxine treatment.

Conclusions: We observed a higher prevalence of SH, but not of TAI, in patients with infertility. Our results support thyroid screening in women with reproductive failure.

MeSH terms

  • Adult
  • Autoimmunity*
  • Case-Control Studies
  • Female
  • Humans
  • Hypothyroidism / complications*
  • Hypothyroidism / drug therapy
  • Hypothyroidism / epidemiology
  • Infertility, Female / complications*
  • Infertility, Female / immunology
  • Pregnancy
  • Pregnancy Rate
  • Prevalence
  • Retrospective Studies
  • Thyroid Gland / immunology*
  • Thyroxine / therapeutic use


  • Thyroxine