Get access



  • Debra J. Jackson RNC, MPH,

    Corresponding authorSearch for more papers by this author
    • 1Debra J. Jackson received her BSN at Florida State University and her MPH in maternal and child health at San Diego State University. Her specialty is perinatal/neonatal nursing, and she is an NCC-certified neonatal intensive care nurse. She is a doctoral candidate in epidemiology at Boston University and works as Research Director at The BirthPlace, where she is coordinating the San Diego Birth Center Study, a prospective comparison study of The BirthPlace program as compared with traditional physician and hospital care.

  • Janet M. Lang PhD, ScD,

    Search for more papers by this author
    • 2Janet M. Lang received her PHD in psychology at the University of New Hampshire and her ScD in epidemiology at the Harvard School of Public Health. Her specialty is perinatal epidemiology, and she is currently Assistant Professor of Epidemiology and Biostatistics at Boston University School of Public Health. She co-directs the analytic teams for two recently completed studies: a randomized trial of active management of labor using Pitocin and nurse-midwives for the reduction of cesarean section and an observational study of risk factors for no prenatal care among inner-city women. She is also a consultant for the national sample survey of certified nurse-midwives. She is the epidemiologist for the San Diego Birth Center Study.

  • Cynthia P. Dickinson CNM, MPH,

    Search for more papers by this author
    • 3Cynthia P. Dickinson received her MSN and nurse-midwifery education and her MPH in epidemiology at Columbia University in New York City. She began her nurse-midwifery career serving low-income families in the Bronx. She was a research associate for the San Diego site of the National Infant Mortality Project and a staff nurse-midwife at the University of California San Diego Medical Center and the Comprehensive Perinatal Program. She is currently Co-Director and full-scope practice nurse-midwife at The BirthPlace, a county wide perinatal program for underserved families.

  • Judith T. Fullerton CNM, PhD

    Search for more papers by this author
    • 4Judith T. Fullerton is Adjunct Professor in the Department of Family and Preventive Medicine, University of California, San Diego, School of Medicine. She received her nurse-midwifery education from Columbia University and her doctorate in health education from Temple. She currently serves as chair for the research committee and interim test consultant for the American College of Nurse-Midwifery Certification Council. Dr. Fullerton has several recent research projects and publications on perinatal services for low-income women in California and served on the advisory council to the National Birth Center Study. She is the Nurse-Midwife Consultant for the San Diego Birth Center Study.

Research Director, The Birth-Place, 4094 4th Ave., #200, San Diego, CA 92103.


Current literature on the safety and efficacy of freestanding birth centers suggests that these centers are safe and have reduced costs for delivery of low-risk women when compared with hospitals. Despite these findings, birth centers continue to arouse controversy and remain limited in number. Potential inequality of birth center and hospital subjects as to perinatal risk is cited as the major methodologic flaw in the current research on birth centers. Defining an appropriate comparison group is arguably the most important methodologic issue encountered in these investigations. Defining women as “low risk” according to standard perinatal risk tools is not an adequate measure of comparability, as these criteria are generally not equivalent to those defining birth center eligibility. The key is to identify groups for comparison that, at baseline, would be expected to have similar outcomes. To address this concern, a tool based on the American College of Nurse-Midwives'Nurse-Midwifery Clinical Data Set was developed to identify valid comparison subjects for birth center research. This tool focuses on birth center eligibility as opposed to traditionally defined risk. This article reviews the issues of population comparability in birth center research and presents the results of a validation study using this newly developed tool.