Thyroid Antibodies Associated With Miscarriage and Preterm Birth

It is becoming increasingly clear that there is an association among maternal thyroid antibodies, miscarriage, and preterm delivery. Thyroid antibodies in women who are clinically and biochemically euthyroid may be an expression of an autoimmune response that otherwise is not affecting their lives. Now, however, evidence is accumulating that the odds of a miscarriage are more than tripled and the odds of preterm birth are doubled in the presence of thyroid autoantibodies.¹

How these antibodies are linked to pregnancy loss or preterm birth is yet to be established, but there are suggestions that treatment with levothyroxine is effective.² Trials are underway that examine its therapeutic efficacy, so testing for thyroid autoantibodies might become sensible if the research is positive in women with recurrent miscarriages or previous preterm labors.