Effect of autoimmune thyroid disease in older euthyroid infertile woman during the first 35 days of an IVF cycle

In this case-control study of euthyroid first-cycle IVF patients ≥38 years old with singleton baby, miscarriage, biochemical pregnancy, and no pregnancy outcomes from 2005–2008, we assayed frozen serum for autoimmune thyroid disease (AITD) and thyroid function at cycle start, trigger, and 4 and 5 weeks’ gestation. AITD prevalence in older infertile women was similar across clinical outcomes, and although AITD was associated with a higher baseline TSH, TSH remained within acceptable ranges, suggesting that T4 supplementation may not affect maternal outcomes in older euthyroid AITD patients through 5 weeks gestation.