Introduction: The vertical integration of primary and specialized care has been identified as a key challenge internationally. In Finland, 23 wellbeing services counties will be responsible for organizing integrated social and health care of primary and specialized care starting 2023. Primary maternity care services are offered in antenatal clinics. Specialized care is offered at 23 maternity hospitals including specialized ante- and postnatal care and childbirth. Specialized maternity care has been burdened due to the ever-increasing number of visits and the insufficient information flow between primary and specialized care. In some wellbeing services counties, services have already been integrated, but no information is available whether this integration has improved processes, outcomes or customer satisfaction. 
 Aims and methods: The first aim is to investigate whether there are differences in maternity care service processes, outcomes and customer satisfaction between the wellbeing services counties. The second aim is to find out perceptions of maternity care managers about the integration of maternity care. Three data sets will be used: the Finnish Medical Birth Register data on all newborns in Finland in 2021 (N=49 726), FinChildren survey on parents with 3-6 months old babies (N=14 820) and qualitative thematic interview among maternity care managers (N=8). All data have been collected and analysis of register and survey data is ongoing. Interview data have been analyzed. 
 Highlights: There are differences in the outcomes and customer satisfaction between the wellbeing services counties. However, more detailed data analyses are needed by adjusting for the most evident confounders and comparing the counties with integrated care to the other counties. These results will be presented at the conference. Maternity care managers felt that the structures within maternity care together with organizational boundaries pose a challenge to integration. Political decision-making was considered to have an influence on maternity care structures. Furthermore, more expertise in maternity care was expected from policy makers to support decision-making. Shared maternity care structure, management, and information systems were seen as factors promoting integration. A partial ambiguity or overlap in the roles between maternity clinics and maternity care at hospitals was observed, as well as inter-professional tensions between public health nurses who are working on primary maternity care and midwives who are working both in primary and specialized maternity care.
 Conclusions: The maternity care system should be more integrated in terms of governance structures, resources, and management. The expertise of maternity care professionals should be utilized in a customer-oriented and cost-effective way. More conclusions will be drawn after finalizing the quantitative analyses.
 Implications: New models of integrated maternity care should be developed, paying attention to the optimal continuity of care from the perspective of pregnant mothers and families. The results of this study can be used to develop the maternity care systems in different countries.