RESUMEN
OBJECTIVE: To investigate whether the live birth rate following in vitro fertilization (IVF) is affected by thyroid autoimmunity (TAI) and/or subclinical hypothyroidism in subfertile women. DESIGN AND SETTING: Retrospective study in a university infertility clinic. PATIENTS: A total of 627 women without past or current history of thyroid disorder undergoing their first IVF cycle. INTERVENTION: Pre-IVF archived blood serum samples were tested for TAI and thyroid function tests. MAIN OUTCOME MEASURE: Live birth rate. RESULTS: The clinical pregnancy rate, live birth rate and miscarriage rate were similar among women with or without TAI and/or subclinical hypothyroidism using a TSH threshold 4·5 mIU/l. Thyroid autoantibody level did not affect these IVF outcomes. CONCLUSION: The live birth rate and miscarriage rate of women with TAI and/or subclinical hypothyroidism following IVF were not impaired.