Timelapse-based 3D reconstruction of blastocysts reveals 3D morphologies of human blastocysts

Assessing blastocysts from a three-dimensional (3D) perspective introduces a novel approach to clinical embryo evaluation. Currently, assisted reproduction laboratories lack clinically compatible methods to reconstruct 3D blastocyst structures without interfering with embryo culture. To address this, we developed an interference-free and non-invasive method that uses widely adopted time-lapse (TL) imaging systems to reconstruct 3D blastocyst structures directly from multi-focal images and quantitatively calculate various 3D morphological parameters, without requiring embryologist intervention. In this study, we reconstructed 3D structures for 2025 blastocysts using 22,275 TL images and analyzed the association between 20 3D morphological features and embryo transfer outcomes. Several parameters were significantly associated with clinical pregnancy and live birth (P < 0.05). This method is fully compatible with current clinical workflows, providing objective and comprehensive 3D data for blastocyst assessment. It holds strong potential for future implementation in standardized and automated embryo selection based on quantitative morphological criteria.