Using the Robson 10-Group Classification System to Compare Cesarean Birth Utilization Between US Centers With and Without Midwives.

This was a secondary analysis of data collected between 2002 and 2008, and cesarean birth practice patterns have changed since then. The data could not reliably show whether a midwife was directly involved in an individual woman's intrapartum care, only whether midwives were intrapartum care providers at the center. Six centers were excluded because midwifery intrapartum care was indeterminate, leaving 3 interprofessional and 3 non-interprofessional centers. 456 births (0.5%) were deleted because key Robson variables were missing, and the analysed sample (96,354) differs from the initial group counts. The included centers were mainly urban, university-affiliated hospitals, so results may not apply to rural or community birth settings. Groups differed in maternal characteristics, especially race, ethnicity, and insurance status, even though some factors were adjusted. The study did not identify reasons for cesarean birth or reasons for induction, so differences in clinical indications cannot be separated. Other unit-level factors, including nursing care environment and nurse-to-laboring-woman ratio, were not captured.

The authors reported no conflicts of interest. The Consortium on Safe Labor data were obtained through data use agreements with the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Do not read the lower cesarean rate as proof that midwives alone caused it. The study compared whole centers with midwife-physician teams against physician-only centers, and the data could not show which provider was involved in each birth. Differences may also reflect center differences, patient mix, induction practices, and factors not measured.