Optical coherence tomography and deep learning for automated oocyte detection in opaque follicular fluid

In in vitro fertilization (IVF), oocytes enclosed in cumulus–oocyte complexes (COCs) must be found in opaque follicular fluid, where transmitted brightfield microscopy (TBM) can miss them. We evaluated whether spectral-domain optical coherence tomography (OCT; 900 nm central wavelength, 3.0 µ m axial resolution in air) combined with a real-time detection transformer (RT-DETR) detects oocyte presence within intact bovine COCs. On an independent test set of 141 wells, with post-denudation confirmation as the reference standard, six embryologists assessing static TBM images detected 65.6–87.0% of oocytes; OCT–RT-DETR detected 99.2% (95% CI 95.8–100%), with 90.0% specificity. OCT-based detection could provide an operator-independent input to automated oocyte search.