#  Haley Sullivan 

Faculty Fellow, Department of Health Services, Policy, and Practice, Brown Universtity School of Public Health

 

 

 



*Dissertation Title*: "Health During Pregnancy: Essays on Access to Care, Preventing Adverse Outcomes, and Health System Structures"

This dissertation investigates how access to care, clinical guidelines, and health system design affect maternal health outcomes in the United States.

**Chapter 1 - Use of Maternal-Fetal Medicine Subspecialist Services by Commercially Insured Pregnant People**  
Improving access to high-quality maternity care and reducing maternal morbidity and mortality are major policy priorities in the United States. Previous research has primarily focused on access to general obstetric care and has not explored access to high-risk pregnancy care provided by maternal-fetal medicine subspecialists (MFMs). Using commercial health insurance claims from the Health Care Cost Institute from 2016-2021, we identified over 2.1 million pregnancies, analyzed the association of patient and pregnancy covariates with MFM involvement in care using logistic regression, and reported rates of telemedicine for pregnancies in urban and rural areas over time. Among pregnancies at risk for conditions that might require MFM involvement, 51.6% had an MFM service. Rates of MFM involvement in care varied considerably by geography, with pregnancies in rural areas having lower use than urban areas. During the COVID-19 pandemic, telemedicine use increased rapidly in many medical fields and policymakers hoped that increased telemedicine would improve access to care for patients in rural areas. This was not the case with MFM care. Prior to the COVID-19 pandemic, less than 1% of all pregnancies had any telemedicine-enabled MFM care. In 2021, 1.7% of rural pregnancies and 2.7% of urban pregnancies had any telemedicine-enabled MFM care. Our results suggest a need to improve access to MFM care for at-risk pregnancies and to further explore expanded access via telemedicine.

**Chapter 2 - Stillbirth in the United States: Burden, Risk Factors, and Fetal Monitoring in Commercially Insured Pregnancies**  
Stillbirth is a tragic outcome impacting nearly 21,000 US pregnancies each year. Many stillbirths happen in the last weeks of pregnancy and are potentially preventable, but prevention efforts in the US have been stymied by limited evidence on stillbirth burden and prenatal stillbirth risk monitoring from novel, large data sources. Using commercial health insurance claims from 2016-2022, we identified singleton pregnancies, assessed stillbirth rates by sociodemographic and clinical risk factors, and examined rates of antenatal fetal surveillance (AFS) by birth outcome and indication. Stillbirth rates varied significantly by area-level measures of race and income, with substantial disparities even for people at lower risk of stillbirth. We also found that new obstetric care guidelines for AFS identify 72% of stillbirths. However, 35% of higher risk pregnancies did not receive guideline-recommended fetal surveillance. Additionally, 28% of stillbirths occurred in lower risk pregnancies, suggesting a need to improve stillbirth risk stratification. To lower stillbirth rates, additional research is needed on the role of AFS in preventing stillbirth and on why some higher risk pregnancies do not receive AFS. Large, novel data sources, particularly those that capture sociodemographic factors, should be further utilized in stillbirth prevention efforts.

**Chapter 3 - Vertical Relationships and Obstetric Care: Impacts on Prices, Quality, and Location of Care**  
Health care practices in the US are increasingly entering into ownership or contracting relationships with hospitals or large health systems (forming so-called vertical relationships). Previous work has found increases in prices after the formation of vertical relationships, with mixed to minimal impacts on quality of care. Pregnancy is one of the leading causes of hospitalization for commercially insured adults, but obstetric vertical relationships have not been well-studied. Using proprietary data on provider vertical relationships with large health systems, Massachusetts All Payer Claims data, and econometric methods for event studies with staggered timing, we found that when obstetric providers enter vertical relationships with large health systems, medical expenditure and the prices paid for ultrasounds significantly increased. There were no significant changes in location of delivery, method of delivery, or quantity of prenatal care received. Our results suggest that increases in spending after obstetric providers form vertical relationships with large health systems can occur even without changes in location of delivery. Changes in the prices of more expensive services, such as ultrasounds, may be driving this increase in spending.



 

 

 





 

 

- ## Dissertation Committee Member
    
     [Anna Sinaiko](/dissertation-committee-member/anna-sinaiko) [Jessica Cohen](/dissertation-committee-member/jessica-cohen) [Meredith Rosenthal](/dissertation-committee-member/meredith-rosenthal)
- ## Concentration
    
     [Methods for Policy Research](/conclabel/methodsforpolicyresearch)
- ## Graduation Year
    
     [2026](/graduation-year/2026)
- ## Role
    
     [Alumni](/people/alumni)