Fetal mortality in Brazil is twice the rate of early neonatal deaths. A package of actions that is specific to the context of a given country can reduce the rate of fetal deaths according to the proportion of causes of death and the prevention strategies available. Thus, identifying the causes of death and analyzing the processes and conditions that contribute to death are important tools in identifying the specific causes of death and identifying preventive strategies. Furthermore, a qualitative approach using the concept of implementation research can be of great importance to better understand the barriers and facilitators associated with the investigation of fetal death and to implement the investigation in the national context. In this project, we propose a multicenter prospective study in five Brazilian maternity hospitals to investigate the impact of the implementation of the CODAC classification of fetal deaths and a post-mortem etiological investigation package of fetal death on the rate of nonspecific causes of fetal death, for the processes of assessment and conditions contributing to death (root cause analysis) and the contributing factors and barriers in the investigation of fetal death against the implementation of a package of standardized investigation procedures in Brazilian maternity hospitals.