Dexamethasone can promote fetal lung maturation and is now widely used in the clinical treatment of preterm infants. Dexamethasone is a glucocorticoid, which can reduce the permeability of capillaries in the lungs, reduce pulmonary edema, promote fetal lung maturation, and facilitate the establishment of autonomic respiration in preterm infants, thus effectively avoiding the abnormal establishment of autonomic respiration in preterm infants after birth due to the imperfect development of the respiratory system and the lack of lung surface active substances, which can avoid the chance of fetal asphyxia after birth and improve the neonatal This prevents postnatal asphyxia and increases the survival rate of the newborn. Dexamethasone is usually administered within 1-7 days before delivery, mainly by intravenous, intramuscular, and amniotic routes, and can significantly reduce the incidence of neonatal respiratory distress syndrome. It should be noted that when dexamethasone is administered intravenously and intramuscularly, it acts on the fetus through the mother, and the dose administered is usually relatively large, which may have a more obvious effect on maternal blood sugar, so the medication should be used under the guidance of a doctor.