Elsevier

Women's Health Issues

Volume 22, Issue 1, January–February 2012, Pages e73-e81
Women's Health Issues

Original article
Comparison of Labor and Delivery Care Provided by Certified Nurse-Midwives and Physicians: A Systematic Review, 1990 to 2008

https://doi.org/10.1016/j.whi.2011.06.005Get rights and content

Abstract

Background

Advanced practice nurses (APNs) in the United States could expand access to high-quality health care, particularly for underserved populations. Yet, there has been limited synthesis of the evidence related to their effectiveness as compared with other providers. The study reported here, part of a larger study that examined all four types of APNs, compares the labor and delivery care outcomes of certified nurse-midwives (CNMs) and physicians.

Data Sources

PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Proquest (for dissertations), were searched for the years 1990 through 2008.

Study Eligibility Criteria

Only those articles where processes or outcomes of care were quantitatively compared between CNMs and physicians were included. For all APNs, 27,993 citations were reviewed. For CNMs, 21 articles representing 18 unique studies reported either infant or maternal outcomes.

Methods

The systematic review followed established procedures (replicable search of relevant databases, sequential review to identify eligible studies, abstraction by two reviewers, assessment of quality, and grading of evidence).

Results

For measures that relate to the processes of care (e.g., epidural, labor induction, episiotomy), lower use was found for CNMs. For many of the infant outcomes (e.g., low Apgar, low birth weight, neonatal intensive care unit admission), there were no differences between physicians and CNMs. Perineal lacerations were lower and breastfeeding was higher among women cared for by CNMs compared with physicians.

Limitations

The review addressed only CNMs practicing in the United States and outcomes measured during labor and delivery. The majority of study designs were observational and the models of care ranged from independent to shared, limiting the control for bias. Moreover, all reviewers were nurses.

Conclusion

Differences in practice between CNMs and MDs seem to be well documented, particularly in the use of technology. Yet, the findings provide evidence that care by CNMs is safe and effective. CNMs should be better utilized to address the projected health care workforce shortages.

Introduction

Advanced practice nurses (APNs) in the United States have the potential to expand access to high-quality health care, particularly for underserved populations. Yet, there has been limited synthesis of the evidence related to their effectiveness compared with other providers. The study reported herein, part of a larger study that examined all four types of APNs, compares the labor and delivery care outcomes of certified nurse-midwives (CNMs) and physicians (Newhouse et al., 2011).

The care of childbearing women and their newborns is the most common reason for hospitalization in the United States (Levit, Wier, Stranges, Ryan, & Elixhauser, 2009). The costs of this care are enormous with maternal and newborn estimates for facility charges alone of $86 billion in 2006 (Andrews, 2008). Although the majority of women and their newborns are healthy with low risk of poor outcomes, obstetrical care in the United States primarily takes place in hospitals with enhanced technology and use of invasive procedures. A 2008 report summarized the research and statistics related to maternity care in the United States (Sakala & Corry, 2008). The comprehensive review revealed gaps in evidence and wide use of practices that are appropriate for mothers and babies only in limited circumstances (e.g., fetal monitoring, erythromycin ophthalmic ointment prophylaxis). Moreover, some practices that are known to be beneficial are underused (e.g., fetal auscultation, vaginal birth after cesarean delivery).

The recent National Institutes of Health consensus conference on Vaginal Birth After Cesarean Birth (Cunningham et al., 2010) has again focused attention on the casual way in which decisions about use of invasive technologies are made during labor and delivery. Midwives view birth as a normal process and emphasize the use of nonpharmacologic approaches to manage birth. A Cochrane review of 11 non-U.S. randomized, controlled trials (RCTs) comparing midwife-led care with medical-led and shared care found that midwife care was associated with many benefits and no adverse effects (Hatem, Sandall, Devane, Soltani, & Gates, 2008). The benefits cited included a reduction in fetal loss before 24 weeks' gestation, use of analgesia, episiotomy, and instrumental births. Midwife led care also increased the chance of a woman having a spontaneous vaginal birth and breastfeeding. There were no differences in risk of fetal death or in cesarean rates. It must be noted that midwives are often the lead providers of care for women with uncomplicated pregnancies in the studies represented in the Cochrane review. This is in contrast with the United States, where medical doctors (MDs) are the primary care providers for most pregnant women.

In the United States, 7.9% of all births are attended by nurse-midwives (Martin et al., 2009). Midwifery care is provided by certified nurse-midwives (CNMs), certified midwives, or certified professional midwives. CNMs are registered nurses who obtain a graduate degree in nursing and pass a national certification examination. Certified midwives graduate from an accredited midwifery program and take the same certification examination, but have no nursing education. Certified professional midwives do not have degree requirements, but are trained primarily through apprenticeship models; they must pass a certification examination. There has been a 33% increase in midwife-attended births in hospitals between 1996 and 2006 (Martin et al., 2009), with CNMs attending the overwhelming majority of hospital births attended by midwives (94.3%). Yet, this estimate is considered low owing to underreporting of midwife-attended deliveries.

Although CNMs view birth as a normal process, the use of appropriate interventions is supported. This is embodied in the Philosophy of the American College of Nurse-midwives which states “appropriate use of interventions and technology” and “consultation, collaboration and referral with other members of the health team” are needed to provide optimal care (American College of Nurse-Midwives, 2004). Regulatory bodies may define criteria for care by nurse-midwives that exclude women at high risk for worse outcomes, although CNMs may care for women with moderate risk (Cragin & Kennedy, 2006). Indeed, most CNMs work in shared models where they care for women with uncomplicated pregnancies and births with the collaboration of physicians.

A meta-analysis compared outcomes of nurse practitioners and CNMs with physicians practicing in the United States (Brown & Grimes, 1995). Of the 15 CNM studies reviewed that controlled for patient risk, CNMs used less technology and analgesia than did physicians in intrapartum care. Neonatal outcomes were equivalent to those of physicians. Although individual studies have compared processes of care and outcomes between CNMs and physicians in the last two decades, there has been no recent systematic review. The study reported herein is unique in that it encompassed observational and experimental designs, applies the developing standards for systematic review, and is the first review since the Brown and Grimes meta-analysis.

Considering the projected inadequate supply of care providers to meet the nation's health care needs, CNMs are seen as a potential solution, particularly for the poor and underserved. The intent of this study was to provide the scientific evidence needed to make informed decisions about obstetrical care delivery and about health care workforce policies.

Section snippets

Review Question

This study compares processes of care and outcomes of births attended by CNMs and physicians in the United States from 1990 to 2008. It is part of a larger systematic review of four APN groups that was commissioned to summarize the findings on how APNs contribute to the safety, quality, and effectiveness of care (Newhouse et al., 2011). For CNMs, the question was specific: Compared with other providers, are CNM patient outcomes similar? Differences in labor and delivery care processes and

Review Methods

The study was undertaken using procedures adapted from the processes specified for Evidence-based Practice Centers funded by the Agency for Healthcare Research and Quality, and guided by an expert co-investigator. These steps include defining the question, searching for studies, selecting studies and collecting data, assessing risk of bias/study quality, addressing reporting bias, summarizing results and interpreting findings, and grading evidence. Whereas a Cochrane review typically seeks RCTs

Results

The review process identified 21 articles or dissertations that provide evidence of CNMs effectiveness as compared with physicians for 13 measures of process or outcome. These reflected 18 unique studies; a few articles represented the same data. The threshold of at least three studies to include the process or outcome was not reached for any prenatal care measure. Therefore, the measures reported here represent only the process and outcomes of labor and delivery care. Furthermore, all of the

Discussion

Based on this systematic review, there is moderate to high evidence that CNMs rely less on technology during labor and delivery than do physicians and achieve similar or better outcomes. Many may view the findings as expected. CNMs and physicians practice differently. Considering that only 5 of the 21 studies were published since 2000, the usefulness of such descriptive studies seems to have been exhausted. Yet, where are the next studies that help us to understand how and why these differences

Meg Johantgen, PhD, RN, an Associate Professor at the University of Maryland School of Nursing, where she teaches research methods and biostatistics. Dr. Johantgen is a trained health service researcher with expertise in using administrative data to measure health outcomes.

References (35)

  • American College of Nurse-Midwives. (2004). Philosophy of the American college of nurse-midwives. Available:...
  • D. Atkins et al.

    Grading quality of evidence and strength of recommendations

    British Medical Journal

    (2004)
  • H. Blanchette

    Comparison of obstetric outcome of a primary-care access clinic staffed by certified nurse-midwives and a private practice group of obstetricians in the same community

    American Journal of Obstetrics and Gynecology

    (1995)
  • S.A. Brown et al.

    A meta-analysis of nurse practitioners and nurse midwives in primary care

    Nursing Research

    (1995)
  • L.R. Chambliss et al.

    The role of selection bias in comparing cesarean birth rates between physician and midwifery management

    Obstetrics and Gynecology

    (1992)
  • Cragin, L. E. (2002). Comparisons of care by nurse-midwives and obstetricians: birth outcomes for moderate risk women....
  • F.G. Cunningham et al.

    National Institutes of Health Consensus Development Conference Statement: Vaginal birth after cesarean: New insights. March 8–10, 2010

    Obstetrics & Gynecology

    (2010)
  • Cited by (72)

    • Bridging the Chasm between Pregnancy and Health over the Life Course: A National Agenda for Research and Action

      2021, Women's Health Issues
      Citation Excerpt :

      The Black Mamas Matter Alliance sets the standard for holistic care for Black women who are disproportionately impacted (Muse, 2018). A robust body of evidence supports the safety and effectiveness of the woman-centric nurse-midwifery model of care (Johantgen et al., 2012) as well as its value for continuity, cost savings, and patient satisfaction (Centers for Medicare and Medicaid Services [CMS] Findings at a Glance, 2019; Institute for Medicaid Innovation, 2020a). Collaborative teams that include nurse-midwives, doulas, and CHWs can extend care across the chasm, ensure standards of holism and “high touch,” and position women for care across the life course (Celi et al., 2019).

    View all citing articles on Scopus

    Meg Johantgen, PhD, RN, an Associate Professor at the University of Maryland School of Nursing, where she teaches research methods and biostatistics. Dr. Johantgen is a trained health service researcher with expertise in using administrative data to measure health outcomes.

    Lily Fountain, MS, CNM, RN, an Assistant Professor at the University of Maryland School of Nursing, is a nurse-midwife and was a member of the Joint Committee on Nurse-Midwifery, Maryland Board of Nursing. Ms. Fountain is currently on the Maryland Breastfeeding Coalition Executive Board.

    George Zangaro, PhD, RN, is an Associate Professor and Director of Research at Catholic University of America. As a retired officer in the U.S. Navy, Dr. Zangaro studies retention in the military health system.

    Robin Newhouse, PhD, RN, NEA-BC, is an Associate Professor and Chair, Organizational Systems and Adult Health. Dr. Newhouse is an internationally recognized expert in evidence-based practice and translation of best practices by nurses.

    Julie Stanik-Hutt, PhD, ACNP, CCNS, FAAN, is an Associate Professor at the Johns Hopkins University School of Nursing. Dr. Stanik-Hutt, an adult Acute Care Nurse Practitioner and a Critical Care Clinical Nurse Specialist, also practices at Johns Hopkins Hospital.

    Kathleen White, PhD, RN, NEA-BC, FAAN, is an Associate Professor at the Johns Hopkins University School of Nursing. Dr. White is widely recognized for her policy expertise.

    Supported by Tri-Council for Nursing and the Advanced Practice Registered Nurse Alliance (PI: Newhouse, Robin).

    View full text