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