早产是导致围产儿死亡的重要原因之一,早产占孕妇总数5%～15%,早产儿中的15%于新生儿期死亡,且在存活的早产儿中10%～30%留有后遗症。因此降低早产发生率对提高产科质量具有重要意义,最重要的措施之一是防止早产和延长妊娠期,即使短时间延长妊娠时间都会对新生儿愈后产 Premature delivery is one of the major causes of perinatal death. Premature birth accounts for 5% to 15% of the total number of pregnant women. 15% of premature children die in the neonatal period, and 10% to 30% of the surviving premature children have sequelae. Therefore, reducing the incidence of preterm birth to improve the quality of obstetrics is of great significance, one of the most important measures to prevent premature birth and prolongation of pregnancy, even a short period of time will be on the extension of pregnancy neonatal prognosis