Midwifery Workforce Density Moderates the Association Between Independent Practice and Pregnancy Outcomes

Abstract

IntroductionStudies comparing pregnancy outcomes before and after state transition to independent midwifery practice have found little change in primary cesarean birth and preterm birth rates. One reason may be the failure to control for midwife density. The objective was to test if the local midwife density moderates the association between state independent midwifery practice and pregnancy outcomes.MethodsBirth records were abstracted from the State Inpatient Databases for 6 states. The Area Health Resource File provided county variables. Midwife density was operationalized as no midwives, low midwife density (<4.5 per 1000 births), and high midwife density (≥4.5 midwives per 1000 births). Multivariate logistic regression models compared primary cesarean birth and preterm birth, controlling for maternal and county characteristics. Moderation was tested by including an interaction term (independent practice × density) to the regression models. The magnitude of association for the interaction was measured by stratifying the models.ResultsThe study included 875,156 women; most (79.7%) resided in a county with low midwife density. Restricted midwifery practice was associated with increased odds of both primary cesarean birth and preterm birth. The interaction term was significant for both preterm birth and primary cesarean, indicating moderation. The largest magnitude of difference was the increased odds of preterm birth in counties with a high midwife density and restricted practice (odds ratio, 3.50; 95% CI, 2.43‐5.06) compared with those with high midwife density and independent practice.DiscussionMidwife density moderates the association between independent midwifery practice and primary cesarean birth and preterm birth. Moderation may explain why prior studies found small or no changes in outcomes when states adopted independent practice. Moderation models can improve testing for associations with independent practice. Both midwife independent practice and increasing midwifery workforce size can be strategies to improve state pregnancy outcomes.

The Relationship Between Restrictive Regulation of Midwives, Practice Environment, and Professional Burnout

“…Restrictive regulation that limits midwifery practice authority has been associated with increased operative and preterm birth, which can lead to moral injury and secondary trauma for the medical team, which, in turn, is associated with attrition from employers or the workforce. 23,41 Furthermore, other state regulations that limit midwives' ability to practice, such as lack of Medicaid reimbursement parity with physicians, have been associated with fewer midwife births and also have the potential to affect the wellbeing of the workforce (eg, increasing the financial burden on a practice with CNMs). 42 Consequently, policymakers are encouraged to advocate for uniform and equitable state-level regulation of midwives as a strategy to strengthen the CNM/CM workforce and improve maternal health outcomes.…”

“…Although we did not find a direct relationship between state regulation of practice authority and burnout in this sample, the potential of state regulation to directly affect midwives' well-being should not be dismissed. Restrictive regulation that limits midwifery practice authority has been associated with increased operative and preterm birth, which can lead to moral injury and secondary trauma for the medical team, which, in turn, is associated with attrition from employers or the workforce 23,41. Furthermore, other state regulations that limit midwives' ability to practice, such as lack of Medicaid reimbursement parity with physicians, have been associated with fewer midwife births and also have the potential to affect the well-being of the workforce (eg, increasing the financial burden on a practice with CNMs) 42.…”

“…21 Furthermore, RR of midwives has not shown any benefit to patients and, to the contrary, states with RR appear to have higher infant and maternal mortality rates and more racialized disparities in maternal health outcomes. 22,23 The effects of government regulation on midwives' practice environments and burnout have not been well studied. The purpose of this mixed-methods sequential study was to investigate the relationship between state regulation that restricts midwives' autonomous practice authority, practice environments, and burnout among CNMs/CMs practicing in states with either restrictive or autonomous state regulation.…”

“…An international critical synthesis determined that regulations that are inconsistent and restrict scope of practice led to disempowerment and marginalization of midwives 21. Furthermore, RR of midwives has not shown any benefit to patients and, to the contrary, states with RR appear to have higher infant and maternal mortality rates and more racialized disparities in maternal health outcomes 22,23. The effects of government regulation on midwives' practice environments and burnout have not been well studied.…”

ACNM’s Commentary on the Midwifery Workforce in the US

“…ACNM supports members to advocate for full-scope independent midwifery practice and achieve Medicaid pay equity in all US states. While numerous studies have documented improved perinatal outcomes in states where midwives are able to practice at full scope of their education preparation without restrictions, 12,[15][16][17] not all state legislation allows for full-scope independent midwifery practice. According to the ACNM Workforce Study, 30 states plus the District of Columbia allow for independent practice while 20 still require a contractual agreement with a physician.…”