Fig. 1From: Individualized embryo selection strategy developed by stacking machine learning model for better in vitro fertilization outcomes: an application studyThe overall flowchart of the proposed hierarchical model. The first-level model was trained using all data except double embryo transfer (DET), with only one embryo implantation to predict single-embryo implantation outcomes. The second level contains two models, which were trained using DET data to predict both DET implantation outcomes and twin risksBack to article page