The aim of this article is to familiarize the reader with the status of regionalized perinatal health care in North America, and specifically in the United States of America, using the Iowa regionalization model. The evolution of the regionalization movement in the late 1960s and early 1970s is reviewed. It is noted that the movement was largely without federal government intervention. The role of the March of Dimes in developing the first set of so-called national guidelines is chronicled. The Iowa model, utilizing some non-tertiary referral centres, is discussed in depth. This model included extensive outreach education for the entire state, and worked well largely because of the lack of competition to the major university teaching hospital located at the University of Iowa in Iowa City. This was not true for many other states and regions because competition did exist between tertiary centres. The impact of managed care systems on the overall role of regionalization is discussed. Suggestions are offered for controlling the impact of third-party payers (managed care) on the quality of perinatal health care. An idealized system of monitoring the impact of regionalization and monitoring the effect of managed care is detailed. Finally, the future of regionalization is discussed in the face of deregionalization in populous areas. The need for the best possible care as close to patients' homes as possible (regionalization) still seems apparent.