Preconceptual thyroid peroxidase antibody positivity in women with recurrent pregnancy losses may contribute to an increased risk for another miscarriage.

In women with at least three recurrent unexplained pregnancy losses, the presence of TPO-ab may contribute to an increased risk of a first-trimester miscarriage, possibly more pronounced in very early pregnancy. TSH levels 2.5-4.0 mU/L do not seem to increase the miscarriage risk.