Live birth rates following in vitro fertilization in women with thyroid autoimmunity and/or subclinical hypothyroidism

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.