The rate of cesarean delivery has increased dramatically over the past decade. Medically elective cesareans are a major factor contributing to this rise. This article discusses the most recent evidence on the perinatal risks of cesarean delivery versus vaginal birth, the economic impact of elective cesarean delivery, and ethical principles related to cesareans performed without medical indication. Physicians' rationales and responses to the issues are reviewed and the recommendations and guidelines of professional organizations are summarized. Available evidence does not lend support to a current shift in clinical practice. Research is needed to adequately compare outcomes of planned cesarean delivery and planned vaginal birth. Until evidence supports medically elective cesarean as a birth option that optimizes outcomes for low-risk mothers and their infants, obstetric care providers should continue to support evidenced-based decision making that includes advocacy for vaginal delivery as the optimal mode of birth.