Normal regulation of thyroid function during pregnancy is essential for maternal and fetal health. Abnormal thyroid function may lead to aggravation of pregnant women\’s own diseases and fetal development disorders. Therefore, accurate assessment of the normal range of thyroid function during pregnancy is important for management during pregnancy. Changes in Thyroid Function During Pregnancy Thyroid function will undergo a series of changes during pregnancy under normal circumstances. In early pregnancy, rising progesterone causes increased levels of thyroxine-binding protein (TBG), which leads to increased levels of total triiodothyronine (TT4) and total triiodothyronine (TT3). At the same time, thyroid-stimulating hormone (TSH) levels also decrease. However, as pregnancy progresses, these changes gradually return to a non-pregnant state. Electronic version of the 40-week pregnancy care guide mobi+epub+azw3+pdf Assessment of thyroid function during pregnancy Common indicators for assessing thyroid function during pregnancy include TSH, TT4 and TT3 levels. TSH is one of the most commonly used indicators, which reflects the regulation of thyroid function. Normal TSH levels during pregnancy range from 0.1-2.5 mIU/L. TT4 and TT3 reflect thyroid hormone levels, and their normal ranges are usually within the non-pregnant reference range. Effects of Thyroid Dysfunction During Pregnancy Thyroid dysfunction during pregnancy may have negative effects on maternal and fetal health. Low thyroid function (hypothyroidism) can cause symptoms such as fatigue and depression in pregnant women, and may increase the risk of premature birth, low birth weight, or delayed cognitive development. In contrast, hyperthyroidism (hyperthyroidism) may lead to complications such as high blood pressure and arrhythmia in pregnant women, and also increases the risk of birth defects and premature birth. Management of thyroid dysfunction during pregnancy For the management of thyroid dysfunction during pregnancy, early screening should be carried out first. It is recommended that all pregnant women undergo TSH testing in the first trimester to rule out thyroid dysfunction. For pregnant women who have been diagnosed with hypothyroidism or hyperthyroidism, appropriate treatment measures should be taken according to the specific situation. For pregnant women with hypothyroidism, reasonable supplementation of thyroid hormone can improve maternal and fetal health. For pregnant women with hyperthyroidism, appropriate treatment should be chosen to control thyroid hormone levels to reduce the risk of complications. Conclusion Normal regulation of thyroid function during pregnancy is crucial for maternal and fetal health. Accurate assessment of the normal range of thyroid function during pregnancy is important for management during pregnancy. Through early screening and reasonable treatment measures, the impact of thyroid dysfunction on maternal and infant health can be reduced. However, it is important to note that each pregnant woman\’s situation is unique, so when managing thyroid dysfunction during pregnancy, an individualized treatment plan should be developed on a case-by-case basis.