This grounded theory study investigates the influence of maternity wear brand image innovation elements on consumer behavior, addressing two main research questions: (1) How to innovate the brand image of maternity wear? and (2) What is the relationship between brand image innovation and consumer behavior in maternity wear? Maternity wear brands play a critical role in meeting the diverse needs of expectant mothers, yet in China, they often lack distinct brand identities and fail to cater to the varied preferences of pregnant women. Through a comprehensive research design, including literature review, grounded theory analysis, and empirical testing via questionnaire surveys, this study identifies six dimensions of brand image innovation in maternity wear: Product, Identity, Corporate, Marketing, Service, and Store image innovation, along with 21 specific indicators such as style and fabric innovation. The findings reveal a significant impact of each dimension of brand image innovation on consumer behavior. Theoretical and managerial implications highlight the study’s contribution in filling a research gap, providing a new framework for brand image research in maternity wear, and offering targeted recommendations for brand innovation efforts. This research expands understanding of the intricate relationship between consumer behavior and brand image, providing theoretical guidance for maternity wear companies to enhance brand appeal, meet diverse consumer needs, and ultimately improve sales and loyalty.