Dexamethasone at 35 weeks of pregnancy has some side effects, but generally does not affect the health of the pregnant woman as well as the growth and development of the fetus. Dexamethasone is a kind of glucocorticoid, mainly used to promote the development of fetal lungs, usually used in preterm labor or medical preterm labor, can promote the maturation of fetal lungs, to avoid fetal respiratory distress syndrome and other conditions after birth. Dexamethasone is not recommended for multiple injections and multiple courses of treatment because of certain side effects, such as gastrointestinal irritation, psychiatric symptoms, and glucocorticoid withdrawal syndrome. In addition, the use of dexamethasone carries a high degree of risk, and it is recommended that mothers should always use it under the supervision of a specialist.