This laboratory technique is used to improve the probability of an embryo implanting into the uterine wall after transfer into the uterine cavity. The embryologist creates a small hole in the outer membrane or shell of the embryo (called the zona pellucida). By creating this thinning of the wall, the embryo is better able to exit its protective “shell” and implant into the uterine lining. Numerous studies have shown that AH improves pregnancy rates and implantation rates. Patients with previous IVF failure, poor embryo growth or quality, moderate to excessive fragmentation, or advanced maternal age may benefit from this additional procedure prior to embryo transfer.