The normal value of thyroid in pregnancy generally refers to thyroid stimulating hormone, and the value is divided into stages, early pregnancy is usually in the range of 0.1-2.5 mlU/L, mid-pregnancy is 0.2-3.0 mlU/L; late pregnancy is 0.3-3.0 mlU/L. Thyroid hormone is an important value during pregnancy, too high or too low may affect the growth and development of the fetus and increase the risk of miscarriage, cessation of development and mental retardation. Generally speaking, during pregnancy, it is necessary to routinely improve the examination of thyroid function, if there is an abnormality, then it is necessary to consult a doctor in time to identify the cause and treat the symptoms. Pregnant women are advised to increase or decrease the intake of iodine-containing foods to avoid affecting thyroid function.