Dr. Oystein Bergoy joins me to discuss the LaPS Study looking at the effect of Zhang's partograph on cesarean deliveries for labor dystocia. www.obgyn.fm feedback@obgyn.fm The frequency of intrapartum caesarean section use with the WHO partograph versus Zhang’s guideline in the Labour Progression Study (LaPS): a multicentre, cluster-randomised controlled trial Friedman E. The graphic analysis of labor. Am J Obstet Gynecol 1954;68: 1568–75.   Zhang J, Troendle JF, Yancey MK. Reassessing the labor curve in nulliparous women. Am J Obstet Gynecol 2002; 187: 824–28. Zhang J, Landy HJ, Branch DW, et al. Contemporary patterns ofspontaneous labor with normal neonatal outcomes. Obstet Gynecol2010; 116: 1281–87.