Research status of gestational thyroid diseases and reference ranges of related diagnostic indexes

Abstract

Gestational thyroid disease has rapidly emerged as one of the most common diseases during pregnancy. There are various of causes, including an increase in prenatal and pregnancy examinations strategies, enlarging of checkup scope and changes of iodine nutritional status in pregnant women. With the accumulation of serum human chorionic gonadotropin (hCG) and estrogen concentrations, blood volume and the strengthening glomerular filtration, the process of pregnancy could have substantial impacts on thyroid functions. The relation between thyroid disorders and adverse pregnancy outcomes has been demonstrated in a great deal of analyses and researches. Thyroxine deficient diseases in pregnant women, including overt hypothyroidism (OH), subclinical hypothyroidism (SCH) and isolated hypothyroidism (IH), do bring about neuropsychological dysplasia of the offspring due to the critical value of thyroid hormone in neuronal migration and myelin formation of fetal brain tissues. The clinical manifestations and signs of early and (or) subclinical gestational thyroid diseases are often overlaped with the physiological manifestations of pregnancy, so laboratory testing on thyroid functions always become the only means for the diagnosis of gestational thyroid diseases. We would review on the research status and controversial focus of gestational thyroid diseases and reference ranges of related diagnostic indexes, to provide references for the diagnosis and treatment of thyroid diseases pregnancy. Key words: Thyroid disease; Thyrotropin; Diagnosis; Thyroxine; Thyroid function tests; Offspring; Pregnant women