Abstract
BACKGROUND: Perinatal regionalization is a systems-level strategy for coordinating care among obstetric facilities to ensure pregnant people receive timely care in facilities with risk-appropriate personnel and services. As regionalized systems of maternal care are only recently emerging, it remains unclear how these systems are being operationalized in practice. Inter-facility transport of pregnant people to risk-appropriate facilities is a critical component of perinatal regionalization systems. In this study, we characterized maternal transport patterns in the state of Georgia following the publication of the updated guidelines for perinatal regionalization by the Georgia Department of Public Health. We then compared transport behavior in practice to the state’s formal designated perinatal regions (DPRs). METHODS: Using birth records in the state of Georgia from 2017 to 2022, we constructed network graphs to represent maternal transport routes among obstetric facilities. We fitted a multivariate logistic regression model to identify factors associated with inter-DPR transports. Finally, we applied a community-detection algorithm to cluster facilities that were observed to transport among each other most frequently and compared these detected facility clusters to Georgia’s formal DPRs. RESULTS: Among 774,639 deliveries, 2,757 (0.36%) involved transports among obstetric facilities. Average maternal transport rates per 1000 resident births were lower in urban counties (4.75 [SD: 4.99]) compared to suburban (13.34 [SD: 9.41]) and rural (13.37 [SD: 8.87]) counties. 17% of transports occurred between facilities in different DPRs. 8 facility clusters were identified and strongly aligned with DPRs (p < 0.001). Inter-DRP transports tended to occur between neighboring DPRs and between facilities belonging to the same healthcare system (p < 0.001). CONCLUSIONS: Network analysis reveals patterns of maternal transports among obstetric facilities. Elevated transport rates suggest a lack of access to risk-appropriate care in rural regions. While maternal transports mostly occurred within the state’s formal DPRs, geography and transporting within the same health systems tended to trump formal perinatal region designations. States can improve the design of perinatal regionalization systems by formalizing existing partnership among obstetric facilities. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-025-13025-9.