title: [Progresses of epidemic trend on preterm birth and related influencing factors].
authors: Institute of Reproductive and Child Health, Peking University, Beijing, China.
authors: Xiao-Liang
authors: XL
authors: Yang
authors: Rong-Wei
authors: RW
authors: Ye
mesh_terms: D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D012307:Risk Factors