Preterm birth is the important cause of neonatal morbidity and mortality. Infection, premature rupture of membranes, multiple pregnancy and maternal serious complication are the common causes of the preterm birth. The preterm birth rates appear remarkable difference in the world. Also, preterm birth incidence is different in different regions of China, and the incidence of iatrogenic preterm birth is higher than that in the developed countries. Intervention of the diseases such as pregnancy-induced hypertension disease, twin pregnancy and infection is helpful to reduce the premature birth incidence.

Premature birth; Incidence; Epidemiologic factors