Assisted Hatching in Frozen Blastocysts

The Zona Pellucida protects the ovum from the penetration of multiple sperm, and from mechanical and physiological damage until the fertilized ovum reaches the uterus. Subsequently, spontaneous hatching occurs, and enables the embryo to attach to the endometrium. The technique of assisted hatching was originally investigated as a means to improve implantation in cases of zona hardening, and is commonly performed in 3‐day embryos. In the current study, the investigators aim to investigate the effect of assisted hatching on 5‐day frozen embryos.