AI for Embryo

Stain‑free detection of embryo polarization using deep learning

Polarization of the mammalian embryo at the right developmental time is critical for its development to term and would be valuable in assessing the potential of human embryos. However, tracking polarization requires invasive fluorescence staining, impermissible in the in vitro fertilization clinic. We proposed the use of artificial intelligence to detect polarization from unstained time-lapse movies of mouse embryos. We assembled a dataset of bright-field movie frames from 8-cell-stage embryos, side-by-side with corresponding images of fluorescent markers of cell polarization. We then trained an ensemble learning model to distinguish whether any bright-field frame showed an embryo before or after onset of polarization. After training, our resulting model got tested on unseen bright-field movie frames and achieved an accuracy of 85% for detecting polarization, significantly outperforming human volunteers trained on the same data (61% accuracy). We discovered that our self-learning model focuses upon the angle between cells as one known cue for compaction, which precedes polarization, but it outperforms the use of this cue alone. In conclusion, we invented a method for detecting a key developmental feature of embryo development that could avoid clinically impermissible fluorescence staining.