Introduction: The utility of screening for antibodies against thyroperoxidase (TPOAb) in early pregnancy remains controversial. The aim of our retrospective follow-up study was to examine the thyroid function of initially euthyroid TPOAb+ women at a longer period after delivery.
Methods: We invited 822 women screened positive for thyroid disorders in the first trimester of pregnancy (9th12th gestational week) for follow-up. This included measurement of TSH, free thyroxine (FT4), TPOAb and filling of a detailed questionnaire regarding family and personal history.
Results: One hundred eighty-nine (23%) of invited women joined the study. Of these, 100 were TPOAb+ and initially euthyroid in pregnancy. Only 49% of all TPOAb+ women had a positive family history for thyroid disorders. Median time between delivery and follow-up reached 22 months. At follow-up, 13% of the initially euthyroid TPOAb+ women had TSH below 0.37 mU/l, 15% had TSH between 4 and 10 mU/l; and 8% had TSH above 10 mU/l. Serum levels of TPOAb in pregnancy were not linked to the development of thyroid dysfunction. Thirty-five percent of those women who were never treated for thyroid disorders developed thyroid dysfunction at the follow-up. Surprisingly, 29% of women who were currently treated for thyroid disease had TSH outside of the normal range at the time of follow-up.
Conclusion: Thirty-six percent of TPOAb+ women euthyroid in early pregnancy have TSH outside of the normal range at 22 months after delivery. The follow-up and treatment of these women is insufficient. TPOAb+ women after delivery should be closely monitored even if they are euthyroid during pregnancy.
Supported by the Grant of The Czech Health Ministry IGA 10662-3.