Day-3 vs Day-5 Assisted Hatching: Impact on Blastocyst Morphology and PGT-A Outcomes

This randomized controlled trial evaluates the effect of assisted hatching (AH) timing on embryo development and genetic outcomes in in vitro fertilization (IVF) cycles with preimplantation genetic testing for aneuploidy (PGT-A). Eligible patients undergoing IVF with PGT-A will have embryos randomized to receive assisted hatching either on Day-3 or Day-5 of culture, prior to trophectoderm biopsy. The primary outcome is the rate of aneuploid blastocysts. Secondary outcomes include blastocyst morphology, expansion stage, and the correlation between morphology and genetic results. The study aims to determine whether earlier or later assisted hatching affects embryo viability and the accuracy of genetic testing. The trial will provide evidence to optimize laboratory protocols in IVF centers.