An alternative model of maternity care for low-risk birth: Maternal and neonatal outcomes utilizing the midwifery-based birth center model.

OBJECTIVE: To assess key birth outcomes in an alternative maternity care model, midwifery-based birth center care. DATA SOURCES: The American Association of Birth Centers Perinatal Data Registry and birth certificate files, using national data collected from 2009 to 2019. STUDY DESIGN: This observational cohort study compared key clinical birth outcomes of women at low risk for perinatal complications, comparing those who received care in the midwifery-based birth center model versus hospital-based usual care. Linear regression analysis was used to assess key clinical outcomes in the midwifery-based group as compared with hospital-based usual care. The hospital-based group was selected using nearest neighbor matching, and the primary linear regressions were weighted using propensity score weights (PSWs). The key clinical outcomes considered were cesarean delivery, low birth weight, neonatal intensive care unit admission, breastfeeding, and neonatal death. We performed sensitivity analyses using inverse probability weights and entropy balancing weights. We also assessed the remaining role of omitted variable bias using a bounding methodology. DATA COLLECTION: Women aged 16-45 with low-risk pregnancies, defined as a singleton fetus and no record of hypertension or cesarean section, were included. The sample was selected for records that overlapped in each year and state. Counties were included if there were at least 50 midwifery-based birth center births and 300 total births. After matching, the sample size of the birth center cohort was 85,842 and the hospital-based cohort was 261,439. PRINCIPAL FINDINGS: Women receiving midwifery-based birth center care experienced lower rates of cesarean section (-12.2 percentage points, p < 0.001), low birth weight (-3.2 percentage points, p < 0.001), NICU admission (-5.5 percentage points, p < 0.001), neonatal death (-0.1 percentage points, p < 0.001), and higher rates of breastfeeding (9.3 percentage points, p < 0.001). CONCLUSIONS: This analysis supports midwifery-based birth center care as a high-quality model that delivers optimal outcomes for low-risk maternal/newborn dyads.

Health outcomes and provider choice under full practice authority for certified nurse-midwives.

Full practice authority grants non-physician providers the ability to manage patient care without physician oversight or direct collaboration. In this study, we consider whether full practice authority for certified nurse-midwives (CNMs/CMs) leads to changes in health outcomes or CNM/CM use. Using U.S. birth certificate and death certificate records over 2008-2019, we show that CNM/CM full practice authority led to little change in obstetric outcomes, maternal mortality, or neonatal mortality. Instead, full practice authority increases (reported) CNM/CM-attended deliveries by one percentage point while decreasing (reported) physician-attended births. We then explore the mechanisms behind the increase in CNM/CM-attended deliveries, demonstrating that the rise in CNM/CM-attended deliveries represents higher use of existing CNM/CMs and is not fully explainable by improved reporting of CNM/CM deliveries or changes in CNM/CM labor supply.

The birth center model of care: Staffing, business characteristics, and core clinical outcomes.

OBJECTIVES: Interest in expanding access to the birth center model is growing. The purpose of this research is to describe birth center staffing models and business characteristics and explore relationships to perinatal outcomes. METHODS: This descriptive analysis includes a convenience sample of all 84 birth center sites that participated in the AABC Site Survey and AABC Perinatal Data Registry between 2012 and 2020. Selected independent variables include staffing model (CNM/CM or CPM/LM), legal entity status, birth volume/year, and hours of midwifery call/week. Perinatal outcomes include rates of induction of labor, cesarean birth, exclusive breastfeeding, birthweight in pounds, low APGAR scores, and neonatal intensive care admission. RESULTS: The birth center model of care is demonstrated to be safe and effective, across a variety of staffing and business models. Outcomes for both CNM/CM and CPM/LM models of care exceed national benchmarks for perinatal quality with low induction, cesarean, NICU admission, and high rates of breastfeeding. Within the sample of medically low-risk multiparas, variations in clinical outcomes were correlated with business characteristics of the birth center, specifically annual birth volume. Increased induction of labor and cesarean birth, with decreased success breastfeeding, were present within practices characterized as high volume (>200 births/year). The research demonstrates decreased access to the birth center model of care for Black and Hispanic populations. CONCLUSIONS FOR PRACTICE: Between 2012 and 2020, 84 birth centers across the United States engaged in 90,580 episodes of perinatal care. Continued policy development is necessary to provide risk-appropriate care for populations of healthy, medically low-risk consumers.

Strong Start Innovation: Equitable Outcomes Across Public and Privately Insured Clients Receiving Birth Center Care.

INTRODUCTION: The Birth Center model of care is a health care delivery innovation in its fourth decade of demonstration across the United States. The purpose of this research was to evaluate the model's potential for decreasing poverty-related health disparities among childbearing families. METHODS: Between 2013 and 2017, 26,259 childbearing people received care within the 45 Center for Medicare and Medicaid Innovation Strong Start birth center sites. Secondary analysis of the prospective American Association of Birth Centers Perinatal Data Registry was conducted. Descriptive statistics described sociobehavioral, medical risk factors, and core clinical outcomes to inform the logistic regression model. Privately insured consumers were independently compared with 2 subgroups of Medicaid beneficiaries: Strong Start enrollees (midwifery-led care with peer counselors) and non-Strong Start Medicaid beneficiaries (midwifery-led care without peer counselors). RESULTS: After controlling for medical risk factors, Strong Start Medicaid beneficiaries achieved similar outcomes to privately insured consumers with no significant differences in maternal or newborn outcomes between groups. Perinatal outcomes included induction of labor (adjusted odds ratio [aOR], 0.86; 95% CI 0.61-1.13), epidural analgesia use (aOR, 1.00; 95% CI, 0.68-1.48), cesarean birth (aOR, 1.16; 95% CI, 0.87-1.53), exclusive breastfeeding on discharge (aOR, 1.11; 95% CI, 0.48-2.56), low Apgar score at 5 minutes (aOR, 1.23; 95% CI, 0.86-1.83), low birth weight (aOR, 1.12; 95% CI, 0.77-1.64), and antepartum transfer of care after the first prenatal appointment (aOR, 1.53; 95% CI, 0.97-2.40). Medicaid beneficiaries who were not enrolled in the Strong Start midwifery-led, peer counselor program demonstrated similar results except for having higher epidural analgesia use (aOR, 1.30; 95% CI, 1.10-1.53) and significantly lower exclusive breastfeeding on discharge (aOR, 0.57; 95% CI, 0.40-0.81) than their privately insured counterparts. DISCUSSION: The midwifery-led birth center model of care complemented by peer counselors demonstrated a pathway to achieve health equity.

Progesterone and Preterm Birth: Using Empirical Research to Explore Structural Racism Within Midwifery-Led Care.

BACKGROUND: Progesterone has been the standard of practice for the prevention of preterm birth for decades. The drug received expedited Food and Drug Administration approval, prior to the robust demonstration of scientific efficacy. METHODS: Prospective research from the American Association of Birth Centers Perinatal Data Registry, 2007-2020. Two-tailed t tests, logistic regression, and propensity score matching were used. RESULTS: Midwifery-led care was underutilized by groups most at risk for preterm birth and was shown to be effective at maintaining low preterm birth rates. The model did not demonstrate reliable access to progesterone. People of color are most at risk of preterm birth, yet were least likely to receiving progesterone treatment. Progesterone was not demonstrated to be effective at decreasing preterm birth when comparing the childbearing people with a history of preterm birth who used the medication and those who did not within this sample. CONCLUSIONS: This study adds to the body of research that demonstrates midwifery-led care and low preterm birth rates. The ineffectiveness of progesterone in the prevention of preterm birth among people at risk was demonstrated.

Outcomes of Cannabis Use During Pregnancy Within the American Association of Birth Centers Perinatal Data Registry 2007-2020: Opportunities Within Midwifery-Led Care.

BACKGROUND: Healthcare providers require data on associations between perinatal cannabis use and birth outcomes. METHODS: This observational secondary analysis come from the largest perinatal data registry in the United States related to the midwifery-led birth center model care (American Association of Birth Centers Perinatal Data Registry; N = 19 286). Births are planned across all birth settings (home, birth center, hospital); care is provided by midwives and physicians. RESULTS: Population data show that both early and persistent self-reports of cannabis use were associated with higher rates of preterm birth, low-birth-weight, lower 1-minute Apgar score, gestational weight gain, and postpartum hemorrhage. Once controlled for medical and social risk factors using logistic regression, differences for childbearing people disappeared except that the persistent use group was less likely to experience "no intrapartum complications" (adjusted odds ratio [aOR] = 0.49; 95% confidence interval [CI], 0.32-0.76; P < .01), more likely to experience an indeterminate fetal heart rate in labor (aOR = 3.218; 95% CI, 2.23-4.65; P < .05), chorioamnionitis (aOR = 2.8; 95% CI, 1.58-5.0; P < .01), low-birth-weight (aOR = 1.8; 95% CI, 1.08-3.05; P < .01), and neonatal intensive care unit (NICU) admission (aOR = 2.4; 95% CI, 1.30-4.69; P < .05). CONCLUSIONS: Well-controlled data demonstrate that self-reports of persistent cannabis use through the third trimester are associated with an increased risk of low-birth-weight and NICU admission.

Salary and Workload of Midwives Across Birth Center Practice Types and State Regulatory Structures.

INTRODUCTION: Expansion of the midwifery-led birth center model of care is one pathway to improving maternal and newborn health. There are a variety of practice types among birth centers and a range of state regulatory structures of midwifery practice across the United States. This study investigated how those variations relate to pay and workload for midwives at birth centers. METHODS: Data from the American Association of Birth Centers Practice Survey and the Bureau of Labor Statistics' report on occupational employment and wage statistics were analyzed to explore how midwife salaries and workload at birth centers compare within and beyond the birth center model. RESULTS: Survey results from 161 birth centers across the United States demonstrate wide variation in nurse-midwife salaries and are inconsistent with nurse-midwife salaries across all settings as reported by the Bureau of Labor Statistics. The reported number of hours worked by midwives within the birth center model is high. Salaries of midwives who work in birth center-only practices were consistently lower than salaries of midwives who worked in blended birth center and hospital practices, independent of the midwife's level of experience, geographic region of the country, and state regulatory structure. DISCUSSION: Further research is needed to understand how to bring salaries and workload for midwives at birth centers into alignment with national averages.

The American College of Nurse-Midwives' Benchmarking Project: A Demonstration of Professional Preservation and Improvement.

Maternal and newborn outcomes in the United States are suboptimal. Care provided by certified nurse-midwives and certified midwives is associated with improved health outcomes for mothers and newborns. Benchmarking is a process of continuous quality assurance providing opportunities for internal and external improvement. Continuous quality improvement is a professional standard and expectation for the profession of midwifery. The American College of Nurse-Midwives Benchmarking Project is an example of a long-standing, midwifery-led quality improvement program. The project demonstrates a program for midwifery practices to display and compare their midwifery processes and outcomes of care. Quality metrics in the project reflect national quality measures in maternal child health while intentionally showcasing the contributions of midwives. The origins of the project and the outcomes for data submitted for 2019 are described and compared with national rates. The American College of Nurse-Midwives Benchmarking Project provides participating midwifery practices with information for continuous improvement and documents the high quality of care provided by a sample of midwifery practices.

Birth Outcomes of Women with Obesity Enrolled for Care at Freestanding Birth Centers in the United States.

INTRODUCTION: Current US guidelines for the care of women with obesity generalize obesity-related risks to all women regardless of overall health status and assume that birth will occur in hospitals. Perinatal outcomes for women with obesity in US freestanding birth centers need documentation. METHODS: Pregnancies recorded in the American Association of Birth Centers Perinatal Data Registry were analyzed (n = 4,455) to form 2 groups of primiparous women (n = 964; 1:1 matching of women with normal body mass indices [BMIs] and women with obese BMIs [>30]), using propensity score matching to address the imbalance of potential confounders. Groups were compared on a range of outcomes. Differences between groups were evaluated using χ2 test for categorical variables and Student's t test for continuous variables. Paired t test and McNemar's test evaluated the differences among the matched pairs. RESULTS: The majority of women with obese BMIs experienced uncomplicated perinatal courses and vaginal births. There were no significant differences in antenatal complications, proportion of prolonged pregnancy, prolonged first and second stage labor, rupture of membranes longer than 24 hours, postpartum hemorrhage, or newborn outcomes between women with obese BMIs and normal BMIs. Among all women with intrapartum referrals or transfers (25.3%), the primary indications were prolonged first stage or second stage (55.4%), inadequate pain relief (14.8%), client choice or psychological issue (7.0%), and meconium (5.3%). Primiparous women with obesity who started labor at a birth center had a 30.7% transfer rate and an 11.1% cesarean birth rate. DISCUSSION: Women with obese BMIs without medical comorbidity can receive safe and effective midwifery care at freestanding birth centers while anticipating a low risk for cesarean birth. The risks of potential, obesity-related perinatal complications should be discussed with women when choosing place of birth; however, pregnancy complicated by obesity must be viewed holistically, not simply through the lens of obesity.

The Experience of Land and Water Birth Within the American Association of Birth Centers Perinatal Data Registry, 2012-2017.

Consumer demand for water birth has grown within an environment of professional controversy. Access to nonpharmacologic pain relief through water immersion is limited within hospital settings across the United States due to concerns over safety. The study is a secondary analysis of prospective observational Perinatal Data Registry (PDR) used by American Association of Birth Center members (AABC PDR). All births occurring between 2012 and 2017 in the community setting (home and birth center) were included in the analysis. Descriptive, correlational, and relative risk statistics were used to compare maternal and neonatal outcomes. Of 26 684 women, those giving birth in water had more favorable outcomes including fewer prolonged first- or second-stage labors, fetal heart rate abnormalities, shoulder dystocias, genital lacerations, episiotomies, hemorrhage, or postpartum transfers. Cord avulsion occurred rarely, but it was more common among water births. Newborns born in water were less likely to require transfer to a higher level of care, be admitted to a neonatal intensive care unit, or experience respiratory complication. Among childbearing women of low medical risk, personal preference should drive utilization of nonpharmacologic care practices including water birth. Both land and water births have similar good outcomes within the community setting.

Strong Start in birth centers: Socio-demographic characteristics, care processes, and outcomes for mothers and newborns.

BACKGROUND: A recent Center for Medicare and Medicaid Innovation report evaluated the four-year Strong Start for Mothers and Newborns Initiative, which sought to improve maternal and newborn outcomes through exploration of three enhanced, evidence-based care models. This paper reports the socio-demographic characteristics, care processes, and outcomes for mothers and newborns engaged in care with American Association of Birth Centers (AABC) sites. METHODS: The authors examined data for 6424 Medicaid or Children's Health Insurance Program (CHIP) beneficiaries in birth center care who gave birth between 2013 and 2017. Using data from the AABC Perinatal Data Registry™, descriptive statistics were used to evaluate socio-behavioral and medical risks, and core perinatal quality outcomes. Comparisons are made between outcomes in the AABC sample and national data during the study period. RESULTS: Childbearing mothers enrolled at AABC sites had diverse socio-behavioral risk factors similar to the national profile. The AABC sites exceeded national quality benchmarks for low birthweight (3.28%), preterm birth (4.42%), and primary cesarean birth (8.56%). Racial disparities in perinatal indicators were present within the Strong Start sample; however, they were at narrower margins than in national data. The enhanced model of care was notable for use of midwifery-led prenatal, labor, and birth care and decreased hospital admission. CONCLUSIONS: Birth center care improves population health, patient experience, and value. The model demonstrates the potential to decrease racial disparity and improve population health. Reduction of regulatory barriers and implementation of sustainable reimbursement are warranted to move the model to scale for Medicaid beneficiaries nationwide.

Outcomes of childbearing Medicaid beneficiaries engaged in care at Strong Start birth center sites between 2012 and 2014.

BACKGROUND: Variations in care for pregnant women have been reported to affect pregnancy outcomes. METHODS: This study examined data for all 3136 Medicaid beneficiaries enrolled at American Association of Birth Centers (AABC) Center for Medicare and Medicaid Innovation Strong Start sites who gave birth between 2012 and 2014. Using the AABC Perinatal Data Registry, descriptive statistics were used to evaluate socio-behavioral and medical risks, and core perinatal quality outcomes. Next, the 2082 patients coded as low medical risk on admission in labor were analyzed for effective care and preference sensitive care variations. Finally, using binary logistic regression, the associations between selected care processes and cesarean delivery were explored. RESULTS: Medicaid beneficiaries enrolled at AABC sites had diverse socio-behavioral and medical risk profiles and exceeded quality benchmarks for induction, episiotomy, cesarean, and breastfeeding. Among medically low-risk women, the model demonstrated effective care variations including 82% attendance at prenatal education classes, 99% receiving midwifery-led prenatal care, and 84% with midwifery- attended birth. Patient preferences were adhered to with 83% of women achieving birth at their preferred site of birth, and 95% of women using their preferred infant feeding method. Elective hospitalization in labor was associated with a 4-times greater risk of cesarean birth among medically low-risk childbearing Medicaid beneficiaries. CONCLUSIONS: The birth center model demonstrates the capability to achieve the triple aims of improved population health, patient experience, and value.