Low-risk nulliparous term singleton vertex (NTSV) cesarean delivery rates and vaginal birth after cesarean delivery rates (VBAC) in California hospitals, 2009. This scatterplot shows the VBAC and NTSV cesarean delivery rates with an unadjusted linear regression line demonstrating their inverse relationship.Fig. 2. Rosenstein. Hospital VBAC and Primary Cesarean Rates. Obstet Gynecol 2013.