关于早产的定义及对早产的认识经历过不同的阶段,目前我国的早产定义是自末次月经第1天开始计算,妊娠28周至37足周间终止者。早产是发展中国家新生儿死亡和发生并发症的主要原因之一。由于对早产病因学研究的重视,在该领域已取得较大进展,但仍有部分病因不明,因此其发病机制尚 About the definition of preterm birth and understanding of premature birth has gone through different stages, at present, the definition of preterm birth in our country is from the first menstruation on the first day of calculation, the termination of 28 weeks to 37 full-week gestational weeks. Preterm birth is one of the major causes of neonatal death and complications in developing countries. Due to the emphasis on the etiology of prematurity, great progress has been made in this field, but some etiologies are still unknown, so its pathogenesis