The aim of this thesis was to develop a valid, reliable, and nationwide usable obstetric telephone triage system for unplanned care requests of pregnant women. Also, we wanted to evaluate the use of the system by healthcare professionals within different hospital settings and patients’ experiences of the system. This thesis contributes to the improvement of current obstetric care processes. This is necessary in view of the increased volume per obstetric emergency care department, the pursuit of high-quality interpretation and documentation of unplanned obstetric care consultations. A telephone triage system adds to this need. As stated in the main findings it can be said that The Dutch Obstetric Telephone Triage System (DOTTS) achieved consensus of healthcare professionals after its development with relevant stakeholders (chapter 2). DOTTS consists of five presenting symptoms: fluid loss, vaginal bleeding, abdominal pain, concerned pregnant/non somatic symptoms and other physical symptoms. DOTTS consists also of five urgency levels: resuscitation & life threatening, emergency, urgent, non-urgent and self-care advice. This thesis showed that a valid (chapter 3) and reliable (chapter 4) estimate of the urgency levels can be made by using DOTTS and that the use of DOTTS can be safely encouraged in obstetric practice. Further, that the use of a valid and reliable telephone triage system contributes to the correct distribution of human and financial resources. In chapter 5 addition, insight into professionals experiences provided valuable information regarding the aspects that support implementation of DOTTS (chapter 5) in practice. Lastly, in an examination of patients’ experience we found that patients perceived that professionals use DOTTS without losing the human touch (chapter 6). In the general discussion three subjects will be discussed: 1) DOTTS as an example of a successful health care transformation, 2) Aspects of successful innovations that contribute to transformation and, 3) Theoretical concepts of multidisciplinary stakeholder engagement and multidisciplinary learning.