妊娠满28周而不足37孕周分娩者称为早产。早产约占分娩总数的5%～15%,75%以上围生儿死亡与早产有关。早产儿死亡的主要原因是胎儿肺不成熟并发新生儿呼吸窘迫综合征(NRDS)。因此确定肺成熟度,促进胎儿、早产儿肺成熟成为降低围生儿发病率和死亡率的关键。1972年,Liggins等首先 28 weeks of pregnancy and less than 37 gestational weeks of childbirth is called premature delivery. Premature birth accounts for about 5% to 15% of the total number of deliveries, and more than 75% of perinatal deaths are related to premature birth. The main cause of death in preterm infants is immature fetal lung complicated with neonatal respiratory distress syndrome (NRDS). Therefore, to determine the lung maturity and promote fetal, premature lung lung maturation become the key to reduce perinatal morbidity and mortality. In 1972, Liggins et al. First