Fig. 1From: Temporal trends of preterm birth in Shenzhen, China: a retrospective studya Temporal trends in rates of overall and subtype-specific preterm births (PTB) in Shenzhen China, 2003-2012. PROM-PTB, preterm birth following premature rupture of membranes; MI-PTB, medically induced preterm birth; S-PTB, preterm birth due to spontaneous preterm labor. b Preterm birth rates by gestational age. c Overall preterm birth rates by maternal age. d Overall preterm birth rates by maternal educationBack to article page