Background: Women with high-risk pregnancies following infertility are vulnerable to anxiety, which may contribute to adverse pregnancy outcomes and impaired prenatal attachment. While previous studies have examined anxiety in infertility or high-risk pregnancy separately, limited evidence exists on theory-based nursing interventions that integrate both conditions to support maternal role attainment. This study addresses this gap by applying an integrated nursing model based on King’s Goal Attainment and Mercer’s Becoming a Mother theories. Purpose: This study aimed to describe how an integrated theory-based nursing model is operationalized within the nursing care process to support maternal role attainment in women with high-risk pregnancies following infertility. Methods: This case series applied an integrated theory-based approach in the nursing care of five women. A seven-day nursing care period was provided to support learning and behavioral adaptation during pregnancy. Participants were pregnant women with a history of infertility who achieved natural conception and presented with high-risk conditions. The integrated model facilitated interactive communication, shared goal setting, and support for maternal role attainment. Results: Participants demonstrated adequate knowledge and strong commitment to pregnancy care but experienced psychosocial challenges, suboptimal prenatal attachment, and limited preparation for childbearing. Theory-based nursing care actively engaged clients in problem identification, goal setting, and collaborative care planning, and was accompanied by improved understanding of health conditions, reduced anxiety, strengthened commitment to prenatal care, and enhanced prenatal attachment across cases. Conclusion: Clients’ participation supported maternal adaptation and role attainment during pregnancy. The integrated theory-based nursing model offers a practical and person-centered framework for women with high-risk pregnancies following infertility. The findings emphasize the importance of shared goal setting and interactive communication as core components of theory-based nursing care in this population. © 2025 by the Authors.