Abstract: The application of antenatal corticosteroid（ACS） can effectively reduce the morbidity and mortality of premature infants，and it is an important prenatal intervention to improve the prognosis of premature infants.The use of ACS should be based on the gestational age due to different fetal development and different responses to ACS.In this paper，the pharmacologic basis，clinical research evidence，controversy and guideline recommendation of ACS at different gestational age will be reviewed based on domestic and foreign literature and guidelines，hoping to provide reference for clinical practice.

Key words: antenatal corticosteroid, gestational age, premature birth

摘要： 产前糖皮质激素（ACS）的应用可有效降低早产儿病率与死亡率，是改善早产儿预后的重要产前干预措施。由于不同孕周胎儿发育和成熟情况不同，对ACS的反应存在差异，因此应基于孕周使用ACS。文章将结合国内外文献及指南就不同孕周使用ACS的药物学基础、临床研究证据、争议、指南推荐几个方面进行阐述，以期为临床实践提供参考。

关键词: 产前糖皮质激素, 孕周, 早产