Figure 1From: Temporal trends in neonatal outcomes following iatrogenic preterm delivery Preterm birth rates per 100 live births among singletons and twins by subtype of preterm birth, namely, spontaneous preterm birth, iatrogenic preterm birth and preterm birth following premature rupture of membranes for over 12 hours (PROM), United States, 1995 to 2005.Back to article page