The authors describe the development of critical pathways for ambulatory obstetric case management. When case management was identified as needed, but published work in outpatient obstetrics could not be found, four nurses used this opportunity to design a cost-effective system leading to quality outcomes. The driving force was the need for a format that directed comprehensive consistent care delivered by a large multidisciplinary health care team. Design issues included capturing leading edge standards of care and user friendly formats for all caregivers. Throughout a period of 2 years, a trifold format was developed for all obstetric patients, and 15 bifold formats were developed for patients with specific high-risk diagnoses. The format design facilitated cost-effective quality care and is expected to improve patient outcomes. A research study has been initiated to measure effectiveness of the design.