A Statewide Collaborative to Support Vaginal Birth and Reduce Unnecessary Cesarean Deliveries

July 8, 2022

Innovation
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Summary

Started in response to rising maternal morbidity and mortality rates in the State of California, the California Maternal Quality Care Collaborative (CMQCC) has conducted several statewide maternal safety and quality initiatives and has provided a model for other large-scale maternal health campaigns.¹ In 2014, after conducting statewide initiatives to address hemorrhage and preeclampsia, the Collaborative began looking at ways to reduce the unnecessary use of cesarean delivery (C-section) in low-risk deliveries.

The initiative was a response to alarming increases in the use of cesarean section. From the mid-1990s through 2009, cesarean delivery rates rose by more than 50%, including increases for births by women in the most populous racial demographic groups (i.e., Hispanic, Non-Hispanic Black, and non-Hispanic White) and primarily driven by cesarean deliveries in low-risk births.² While cesarean delivery may be the safest option in certain births, in others, the risks associated with the procedure, which include infant respiratory issues, maternal hemorrhage and even mortality (especially with repeated cesareans), and long-term complications like infertility,³ may outweigh the benefits.

To address these issues in California, the Collaborative began a series of multi-year, coordinated hospital-level and statewide initiatives designed to support vaginal birth for deliveries least likely to require cesarean section. The Collaborative focused on deliveries with the following characteristics: nulliparous (mother’s first-time giving birth), term (birth at or beyond 37 weeks’ gestation), singleton (e.g., not twins), and vertex (not breech or transverse position)—collectively referred to as NTSV births. The cesarean rate among this low-risk population was used for the Healthy People 2020 and 2030 goal, as the Centers for Medicare & Medicaid Services (CMS) Core measure, and by the Joint Commission (PC-02), Leapfrog Group, and U.S. News & World Report as a hospital quality measure. There is tremendous variation in hospital care, with low-risk cesarean rates ranging from 2.4% to 36.5% across hospitals.⁴ These variations are attributed to hospital and provider factors as well as to regional risk factors.⁶ Additionally, there is great variation in use of cesarean in low-risk births across states, ranging from roughly 18% to 30.9% in 2021.^5,6

In 2016, 24 hospitals (the first of three cohorts of hospitals all with NTSV cesarean delivery rates over 23.9%), participated in the CMQCC vaginal birth initiative.⁷ The initiative included multiple strategies, such as the use of data for real-time feedback at the clinician and hospital levels, shared learning groups, education of the public, incentives for hospitals with reduced NTSV births, and disincentives for not reducing cesarean rates. A total of 91 hospitals participated in one of three annual CMQCC collaboratives, while several health systems conducted their own internal efforts, and all 220 California hospitals were exposed to state-wide actions such as public reporting and incentives. A study found that the rate of cesarean delivery for NTSV births in California (n=7,574,889 births) decreased from 26.0% in 2014 (which was the same as the U.S. rate) to 22.8% in 2019,³while the U.S. rate remained steady.¹⁰

To implement statewide maternal health safety and quality improvement projects and conduct research, the Collaborative leveraged a range of private and public partners. A crucial element of the approach was utilizing a rapid-cycle Maternal Data Center that captures real-time reporting on births from over 210 California hospitals (covering 96% of all births in the state).⁸ CMQCC leaders point to the use of audit and feedback strategies, awarding and recognizing improvement, and elevating the role of experienced nurses as key strategies for effective implementation.

Innovation Patient Safety Focus

High rates of cesarean delivery are a concern in the United States and around the world.^9,10 In the United States the rate of cesarean deliveries varies greatly across regions and hospitals. The variation is only partly attributable to clinical factors.¹¹

In the context of rising maternal morbidity, unnecessary cesarean deliveries have been identified as an area for safety and quality improvement.¹² The goal of CMQCC’s vaginal birth initiative was to decrease rates of cesarean delivery for low-risk (i.e., NTSV) cesarean births in the State of California. Risks to maternal health that are associated with cesarean births include infection, anesthesia-related risks, blood loss, blood clots, and longer recovery periods (i.e., risks associated with any major surgery). Cesarean sections can also impact fertility and make subsequent cesarean sections riskier.¹³ Babies delivered via cesarean section are at risk for respiratory problems and surgical injury.¹⁴ Cesarean deliveries are thought to contribute to poorer birth outcomes for Black/African American women, including higher rates of infant mortality.¹⁵ Overuse of cesarean deliveries also increases cost to the healthcare system.¹⁶

National, state, and local efforts have not yet made progress on reducing disparities in birth outcomes between women of different races. The rates of low-risk cesareans are highest for non-Hispanic Black women, Asian women, and women over the age of 40.¹⁷Because of the persistent nature of these disparities, there is increased focus on the national and local levels on maternal health equity.^18,19,20 Current work is focused on combining the general efforts for reducing cesarean deliveries with specific birth equity activities.

Resources Used and Skills Needed

Resources to implement and operate a large-scale initiative in support of vaginal birth include:

Input from multiple stakeholders, including policymakers, payers, healthcare administrators, clinicians, and patients
A multi-pronged patient safety bundle that includes a toolkit for clinicians and educational resources for consumers
Data collection methods and a centralized data repository
Measures of progress and a means to report progress on measures back to hospitals on a regular basis
Reports in a format that allows hospitals to track performance against other sites across a state or region, track clinician rates, and drill down to review individual cases
In-person and virtual learning sessions
Local experts to provide mentoring
A system of incentives (e.g., honors, gift cards, financial incentives) provided to clinicians and hospitals that show improvement
Financial disincentives through state Medicaid
Monthly calls with hospital leaders and champions
Site visits and technical assistance
A means for peer-group sharing of best practices

Use By Other Organizations

Lessons from the CMQCC can be used to inform efforts across the country.²¹ The CMQCC Maternal Data Center recently expanded beyond California to support state perinatal quality collaboratives in Washington and Oregon.

All 50 states have established, or are in the process of developing, similar perinatal collaboratives.²² The Centers for Disease Control and Prevention (CDC) provides funding in a number of states for perinatal quality collaboratives that aim to improve health outcomes for women and newborns.²³ The Health Resources and Services Administration (HRSA) supports the Alliance for Innovation on Maternal Health (AIM) program, that works to align national and state efforts to improve maternal health and reduce maternal morbidity and mortality.²⁴ AIM produces a series of national patient safety maternal health bundles that includes a bundle on reducing primary cesareans.²⁵ The AIM safety bundle and CMQCC Toolkits are available on-line.^26,27

Date First Implemented

2006

Problem Addressed

In the last several decades, low-risk cesarean births have been rising in the United States and worldwide.²⁸ An increase in cesarean sections from the mid-1990s through around 2010 (when the rate reached over 30% of all births) was not associated with improved outcomes for moms or babies.²⁹

In 2020, the cesarean section rate in the United States was about one-third of all births, and 25.9% of NTSV births.³⁰ The World Health Organization (WHO) recommends that the cesarean section rate not go above 10 to 15%.³¹ The 2020 Healthy People goal was for cesarean sections to be under 23.9% (and later revised to 24.7%) of all low-risk first-birth births.¹⁴

The overuse of this surgical procedure leads to higher rates of maternal complications such as infection and hemorrhage, results in longer recovery times, and can put the baby at risk.³² Maternal mortality after C-section is higher than after vaginal delivery; worsening of an underlying disease, bleeding, and acute heart failure are among the most common reasons for death following a C-section.³³ In the long term, cesarean birth is also associated with increased risk of fertility problems and complications with future pregnancy.

Description of the Innovative Activity

Every year since 2006, the CMQCC has gathered a multidisciplinary committee to examine maternal deaths and identify the causes of these deaths. This information is used to inform quality and safety improvement efforts. Prior to the vaginal birth initiative, CMQCC focused initiatives on reducing hemorrhage, preeclampsia, and hypertension in maternal care.

Using certain strategies from past innovations, CMQCC’s multimodal initiative to support vaginal birth included the following components:

Use of the CMQCC Maternal Data Center to collect and report on data
Publishing the cesarean delivery rate for NTSV births at every California hospital on Cal Hospital Compare (http://www.CalHospitalCompare.org) and on each hospital’s Yelp.com landing page
Presenting awards to hospitals with lower NTSV C-section rates by the Secretary of Health and Human Services for California
Health plan incentives to participate
Launch of a patient education website: My Birth Matters
Use of CMS §1115 waiver process to incentivize participation
Mentorship, technical assistance, and individual coaching for implementation
Webinars
Training materials for hospital trainers
Shared learning—peer learning groups of hospitals
Development and use of a toolkit and implementation guide for participating sites
- Use of American College of Obstetricians and Gynecologists and Society for Maternal-Fetal Medicine guidelines and enhanced labor support
- Toolkits with training materials for use at individual institutions³⁴

Conducting a survey and analysis of barriers and facilitators to implementation, used to inform each hospital’s approach. Where possible, the analysis included a review of data indicating the drivers for each hospital’s cesarean delivery rate

Hospitals with rates of cesarean delivery greater than 23.9% for NTSV births were invited to participate in an 18-month quality improvement collaborative. Three cohorts of hospitals participated between July 2016 and June 2019.⁴
Providing hospitals statistics at the level of individual doctors
Recognition of individual clinicians
Publishing early collaborative data demonstrating the infant safety of lowering the cesarean rate, addressing the worries of some obstetricians³⁵
The data center recently expanded to support perinatal quality collaboratives in Washington State and Oregon.

Reduction of cesarean deliveries has been an unsuccessful undertaking for well over a generation and CMQCC strongly felt that, in order to be successful in this project, they needed to “pull all the levers at once.” That specifically included all of the actions above and engaging all of the organizations listed in “Funding Sources and Partner Organizations.”

Context of the Innovation

Rates of cesarean delivery nearly doubled from 1996 to 2009, when it reached over 30%.² The increase caused alarm because, while cesarean delivery is sometimes the safest option, the risks may outweigh the benefits for low-risk births. When the CMQCC innovation started, California was part of a national trend of increased cesarean deliveries. Increases in cesarean deliveries for NTSV births are believed to be the reason for this trend.

Of additional concern, research found large variation in use of the procedure across states and hospitals, and high rates could not always be linked to clinical factors.³⁶ Instead, the reasons for the increase in use of cesarean section were primarily attributable to physician beliefs and hospital culture. A 2014 study of women who gave birth found that 14.8% of respondents perceived pressure from a clinician for labor induction and 13.3% for cesarean delivery.³⁷ African American women have the highest rates of NTSV cesarean sections compared to other races, suggesting discrepancies in maternal care, and leading some to suggest that hospital and clinician bias may play a role in adverse maternal outcomes.^10,38

Cesarean births are also more expensive than vaginal births, at $17,004 versus $12,235, respectively,³⁹ and eliminating unnecessary C-sections is a high priority for payers. Medicaid is financially responsible for half of all U.S. births.⁴⁰ Maternity care is the most frequent overall reason for hospitalization, and cesarean section is the most common surgery.⁴¹

Results

In an observational study of 7,574,889 NTSV births that compared the rates of cesarean delivery between 2014 and 2019, the rates in California decreased from 26.0% to 22.8%.⁹ This study reports that the cesarean delivery rate for NTSV births in the United States (excluding California) was 26.0% in both 2014 and 2019. Of California hospitals with a baseline rate of cesarean delivery over 23.9% for NTSV births, 91 (61%) participated in the program.⁹ Compared with hospitals that were not participating in, or exposed to, the statewide campaign, and adjusting for patient characteristics, exposure to collaborative activities was associated with lower odds of cesarean delivery for NTSV births (24.4% vs 24.6%), the study found.

An earlier study found no evidence of worsened birth outcomes during the same period, even in hospitals with large cesarean delivery rate reductions.⁴²Qualitative research found that hospitals that showed less or no improvement had physicians who were less likely to endorse best practices like midwifery. Nurses at hospitals with lower NTSV cesarean rates are more likely to report a culture that is supportive of vaginal birth.²³

Planning and Development Process

To develop an innovation like CMQCC’s vaginal birth initiative, CMQCC leaders say that it is important to start with clearly identifying the problem and establishing why it should be addressed among many stakeholders. In the case of promoting vaginal birth, it is important to understand how C-section rates impact maternal morbidity.

In the planning phase, CMQCC leadership say teams planning to implement this innovation should reach out to stakeholders and private/public partners to get input, buy-in, and participation. Additionally, they recommend that innovation leaders:

Evaluate cost and obtain funding.
Identify data to be collected, how it will be captured, by whom, and how often.
Create tools and templates for data collection.
Select 2 or 3 quality measures that can be tracked over time (using standardized national measures).
Collect baseline data.
Discuss incentives.
Create toolkit task forces to prepare different educational and implementation materials for sites.
Initiate development of educational materials and a dissemination plan for the public.
Involve experts across the state or region to develop materials and support implementation.
Establish regional leaders.
Create a state-wide set of partner organizations (as inclusive as possible) all invested in the goals and approaches of the initiative.

Resources Used and Skills Needed

Resources to implement and operate a large-scale initiative in support of vaginal birth include:

Input from multiple stakeholders, including policymakers, payers, healthcare administrators, clinicians, and patients
A multi-pronged patient safety bundle that includes a toolkit for clinicians and educational resources for consumers
Data collection methods and a centralized data repository
Measures of progress and a means to report progress on measures back to hospitals on a regular basis
Reports in a format that allows hospitals to track performance against other sites across a state or region, track clinician rates, and drill down to review individual cases
In-person and virtual learning sessions
Local experts to provide mentoring
A system of incentives (e.g., honors, gift cards, financial incentives) provided to clinicians and hospitals that show improvement
Financial disincentives through state Medicaid
Monthly calls with hospital leaders and champions
Site visits and technical assistance
A means for peer-group sharing of best practices

Funding Sources

The CMQCC reports that the following organizations financially supported the vaginal birth initiative:

The California Health Care Foundation (CHCF)
Yellow Chair Foundation
HRSA Alliance for Innovation on Maternal Health (AIM)
Blue Shield Foundation
Participating hospitals
California Department of Public Health

Critical to the success of the program was the active participation of the California Hospital Association, multiple hospital system leaders, obstetric, nursing, midwifery, and family medicine organizations, multiple purchasers and organizations, health plans including the California Department of Health Care Services (the Medicaid agency), and a variety of community groups.

Getting Started with This Innovation

To get started with the innovation, it is important to make sure the foundations of surveillance, reporting, and multidisciplinary partnerships are in place. Using collected data, a collaborative would want to identify underperforming hospitals, and then work with stakeholders to determine an appropriate intervention (or interventions) for these hospitals. Part of determining interventions is to survey hospitals and help them to determine which approaches are most appropriate for their settings. Then the collaborative can create peer learning groups to support implementation by participating hospitals.

Sustaining This Innovation

The CMQCC believes the keys to sustaining the collaborative and the vaginal birth innovation include the following steps:

Before implementation, building a solid foundation: performing surveillance, mobilizing partners, and establishing data collection and reporting methods
Using multidisciplinary experts from throughout the targeted region working together to make toolkits and organizational guides
Working with professional societies to highlight data and toolkits produced by the innovation
Engaging high-level government officials, health plans, and hospital leadership
Using a single data center with automated transmission and flexibility to collect and report on a variety of measures (helps reduce burden on hospitals and provides real-time updates)
Calculating measures approximately every month based on customized measurement specifications
Developing trend charts to communicate results with participating hospitals and providers on a regular basis
Showing the public and stakeholders maternal and infant outcomes pre- and post- implementation (along with other relevant findings)
Emphasizing a collaborative learning process and the use of collective wisdom across hospitals and across providers
Engaging nurses and helping them own the management of labor
Using incentives and rapid-cycle data as strategies and motivators for change
- Comparing doctors locally who have the same nursing staff
- Cultivating C-suite engagement and presenting awards to CEOs
Working with payers on incentivizing change/disincentivizing cesarean delivery for low-risk births

References/Related Articles

Alliance for Innovation in Maternal Health. AIM Process. https://saferbirth.org/about-us/aim-process/. Accessed March 3, 2022.

Centers for Disease Control and Prevention. Developing and Sustaining Perinatal Quality Collaboratives. 2016. https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pdf/best-practices-for-developing-and-sustaining-perinatal-quality-collaboratives_tagged508.pdf. Accessed March 3, 2022.

California Maternal Quality Care Collaborative. Toolkit to Support Vaginal Birth and Reduce Primary Cesareans. https://www.cmqcc.org/VBirthToolkitResource. Accessed March 3, 2022.

Main EK, Chang SC, Cape V, Sakowski C, Smith H, Vasher J. Safety assessment of a large-scale improvement collaborative to reduce nulliparous cesarean delivery rates. Obstet Gynecol. 2019 Apr;133(4):613-623. doi: 10.1097/AOG.0000000000003109. PMID: 30870288.

Main EK, Markow C, Gould J. Addressing maternal mortality and morbidity in California through public-private partnerships. Health Affairs. 2018;37(9):1484-1493.

Okwandu IC, Anderson M, Postlethwaite D, Shirazi A, Torrente S. Racial and ethnic disparities in cesarean delivery and indications among nulliparous, term, singleton, vertex women. J. Racial and Ethnic Health Disparities. 2021. doi:10.1007/s40615-021-01057-w.

Rosenstein MG, Chang SC, Sakowski C, et al. Hospital quality improvement interventions, statewide policy initiatives, and rates of cesarean delivery for nulliparous, term, singleton, vertex births in California. JAMA. 2021 Apr 27;325(16):1631-1639. doi: 10.1001/jama.2021.3816. PMID: 33904868; PMCID: PMC8080226.

VanGompel ECW, Perez SL, Datta A, Carlock FR, Cape V, Main EK. Culture that facilitates change: a mixed methods study of hospitals engaged in reducing cesarean deliveries. The Annals of Family Medicine. 2021;19(3):249-257.

Footnotes

[1] California Maternal Quality Care Collaborative. Who We Are. https://www.cmqcc.org/who-we-are. Accessed March 3, 2022.

[2] Osterman MJK, Martin JA. Trends in low-risk cesarean delivery in the United States, 1990–2013. National vital statistics reports; vol 63 no 6. Hyattsville, MD: National Center for Health Statistics. 2014.

[3] Main EK, Morton CH, Melsop K et al. Creating a public agenda for maternity safety and quality in cesarean delivery. Obstet Gynecol. 2012 Nov;120(5):1194-1198. doi: http://10.1097/AOG.0b013e31826fc13d.

[4] Kozhimannil KB, Law MR, Virnig BA. Cesarean delivery rates vary tenfold among US hospitals; reducing variation may address quality and cost issues. Health Affairs. 2013 Mar 1;32(3):527-35.

[5] Hamilton BE, Martin JA, Osterman MJ. Births: Provisional data for 2020.

[6] Ouyang L, Cox S, Ferre C, Xu L, Sappenfield WM, Barfield W. Variations in Low-Risk Cesarean Delivery Rates in the United States Using the Society for Maternal-Fetal Medicine Definition. Obstetrics & Gynecology. 2022 Feb 1;139(2):235-43.

[7] Rosenstein MG, Chang S, Sakowski C, et al. Hospital Quality Improvement Interventions, Statewide Policy Initiatives, and Rates of Cesarean Delivery for Nulliparous, Term, Singleton, Vertex Births in California. JAMA. 2021;325(16):1631–1639. doi:10.1001/jama.2021.3816

[8] California Maternal Quality Care Collaborative. What We Do. https://www.cmqcc.org/about-cmqcc/what-we-do. Accessed March 3, 2022.

[9] Department of Health and Human Services Office of Disease Prevention and Health Promotion. Healthy People 2020. Maternal, Infant, and Child Health. https://www.healthypeople.gov/2020/topics-objectives/topic/maternal-infant-and-child-health. Accessed March 3, 2022.

[10] World Health Organization. Caesarean sections should only be performed when medically necessary says WHO. April 9, 2015. https://www.who.int/news/item/09-04-2015-caesarean-sections-should-only-be-performed-when-medically-necessary-says-who. Accessed March 3, 2022.

[11] Kozhimannil KB, Law MR, Virnig BA. Cesarean delivery rates vary tenfold among US hospitals; reducing variation may address quality and cost issues. Health Affairs. 2013 Mar 1;32(3):527-35.

[12] Department of Health and Human Services Office of Disease Prevention and Health Promotion. Healthy People 2030. Reduce cesarean births among low-risk women with no prior births – MICH-06. https://health.gov/healthypeople/objectives-and-data/browse-objectives/pregnancy-and-childbirth/reduce-cesarean-births-among-low-risk-women-no-prior-births-mich-06. Accessed March 3, 2022.

[13] Keag OE, Norman JE, Stock SJ. Long-term risks and benefits associated with cesarean delivery for mother, baby, and subsequent pregnancies: Systematic review and meta-analysis. PLoS Med. 2018;15(1):e1002494. doi:10.1371/journal.pmed.1002494.

[14] Mayo Clinic. C-section. https://www.mayoclinic.org/tests-procedures/c-section/about/pac-20393655#:~:text=A%20C%2Dsection%20might%20increase,Wound%20infection. Accessed March 3, 2022.

[15] Holmes L Jr, O'Neill L, Elmi H, et al. Implication of Vaginal and Cesarean Section Delivery Method in Black-White Differentials in Infant Mortality in the United States: Linked Birth/Infant Death Records, 2007-2016. Int J Environ Res Public Health. 2020;17(9):3146. Published 2020 Apr 30. doi:10.3390/ijerph17093146

[16] Valdes EG. Examining cesarean delivery rates by race: a population-based analysis using the Robson ten-group classification system. J. Racial and Ethnic Health Disparities. 2021;8:844-851. doi:10.1007/s40615-020-00842-3.

[17] Ouyang L, Cox S, Ferre C, Xu L, Sappenfield WM, Barfield W. Variations in Low-Risk Cesarean Delivery Rates in the United States Using the Society for Maternal-Fetal Medicine Definition. Obstet Gynecol. 2022 Feb 1;139(2):235-243. doi: 10.1097/AOG.0000000000004645. PMID: 34991146.

[18] Marill MC. Raising The Stakes To Advance Equity In Black Maternal Health: Article examines efforts to improve maternal health equity for Black women.

[19] King PA, Henderson ZT, Borders AE. Advances in Maternal Fetal Medicine: perinatal quality collaboratives working together to improve maternal outcomes. Clinics in Perinatology. 2020 Dec 1;47(4):779-97.

[20] Reno R, Warming E, Zaugg C, Marx K, Pies C. Lessons Learned from Implementing a Place-Based, Racial Justice-Centered Approach to Health Equity. Maternal and Child Health Journal. 2021 Jan;25(1):66-71.

[21] VanGompel EC, Perez SL, Datta A, Carlock FR, Cape V, Main EK. Culture that facilitates change: a mixed methods study of hospitals engaged in reducing cesarean deliveries. The Annals of Family Medicine. 2021 May 1;19(3):249-57.

[22] Centers for Disease Control and Prevention. State Perinatal Qualitiy Collaboratives. State Perinatal Quality Collaboratives | Perinatal | Reproductive Health | CDC. Accessed May 12, 2022.

[23] Centers for Disease Control and Prevention. Developing and Sustaining Perinatal Quality Collaboratives. 2016. https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pdf/best-practices-for-developing-and-sustaining-perinatal-quality-collaboratives_tagged508.pdf. Accessed March 3, 2022.

[24] Rosenstein MG, Chang S, Sakowski C, et al. Hospital Quality Improvement Interventions, Statewide Policy Initiatives, and Rates of Cesarean Delivery for Nulliparous, Term, Singleton, Vertex Births in California. JAMA. 2021;325(16):1631–1639. doi:10.1001/jama.2021.3816

[25] HRSA. Alliance for Innovation on Maternal Health. Communities of Learning. https://saferbirth.org/aim-resources/communities-of-learning/cols-2022-2023/. Accessed March 3, 2022.

[26] California Maternal Quality Care Collaborative: Toolkit to Support Vaginal Birth and Reduce Primary Cesareans. 2016. https://www.cmqcc.org/VBirthToolkit

[27] Alliance for Innovation on Maternal Health: Safe Reduction of Primary Cesarean Birth. 2015. https://saferbirth.org/psbs/safe-reduction-of-primary-cesarean-birth/

[28] Betrán AP, Ye J, Moller A-B, et al. The increasing trend in caesarean section rates: global, regional and national estimates: 1990-2014. PloS one. 2016;11(2):e0148343.

[29] Main EK, Morton CH, Melsop K, Hopkins D, Giuliani G, Gould JB. Creating a public agenda for maternity safety and quality in cesarean delivery. Obstet Gynecol. 2012 Nov;120(5):1194-8. doi: 10.1097/aog.0b013e31826fc13d. PMID: 23090538.

[30] National Center for Health Statistics. Births – Method of Delivery. https://www.cdc.gov/nchs/fastats/delivery.htm. Accessed March 3, 2022.

[31] World Health Organization. WHO Statement on Caesarian Section Rates. 2015. https://www.who.int/publications/i/item/WHO-RHR-15.02. Accessed March 3, 2022.

[32] American Pregnancy Association. C-Section Complications. https://americanpregnancy.org/healthy-pregnancy/labor-and-birth/c-section-complications/. Accessed March 3, 2022.

[33] Miseljic N, Ibrahimovic S. Health implications of increased cesarean section rates. Mater Sociomed. 2020;32(2):123-126. doi:10.5455/msm.2020.32.123-126.

[34] Main EK, Markow C, Gould J. Addressing maternal mortality and morbidity in California through public-private partnerships. Health Affairs. 2018;37(9):1484-1493.

[35] Main EK, Chang S, Cape V, Sakowski C, Smith H, Vasher J. Safety Assessment of a Large-Scale Improvement Collaborative to Reduce Nulliparous Cesarean Delivery Rates. Obstet Gynecol 2019;133: Apr;133(4):613-623

[36] Backes Kozhimannil K, Golberstein E. Cesarean Rates: Shifting the Focus from Increases to Variability in Use. Health Affairs Blog, January 15, 2014. doi:10.1377/hblog20140115.036442.

[37] Jou J, Kozhimannil KB, Johnson PJ, Sakala C. Patient-perceived pressure from clinicians for labor induction and cesarean delivery: a population-based survey of U.S. women. Health Serv Res. 2015;50:961-981. doi:10.1111/1475-6773.12231

[38] Martin JA, Hamilton BE, Osterman MJK. Births in the United States, 2020. NCHS Data Brief, no 418. Hyattsville, MD: National Center for Health Statistics. 2021. doi:10.15620/cdc:109213external icon.

[39] Melillo G. How much does it cost to give birth in the United States? It depends on the state. American Journal of Managed Care. 2020.

[40] Kaiser Family Foundation. Births Financed by Medicaid 2020. https://www.kff.org/medicaid/state-indicator/births-financed-by-medicaid/?currentTimeframe=0&sortModel=%7B%22colId%22:%22Location%22,%22sort%22:%22asc%22%7D. Accessed March 3, 2022.

[41] Healthcare Cost and Utilization Project (HCUP). HCUP Fast Stats – Most Common Diagnoses for Inpatient Stays. April 2021. Agency for Healthcare Research and Quality, Rockville, MD. https://datatools.ahrq.gov/sites/default/files/2022-10/DownloadTable_Most%20Common%20Diagnoses_10-3-22.xls. Accessed March 3, 2022.

[42] Main EK, Chang SC, Cape V, Sakowski C, Smith H, Vasher J. Safety Assessment of a Large-Scale Improvement Collaborative to Reduce Nulliparous Cesarean Delivery Rates. Obstet Gynecol. 2019 Apr;133(4):613-623. doi: 10.1097/AOG.0000000000003109. PMID: 30870288.

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