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