Human embryo under un-optimal external environment factor, the outer shell of the egg may possible become thicken and harden unable to hatch and failed to implant. With the help of assisted hatching it may help to improve this implantation.
Although assisted hatching is widely used in the ART practice, however because of uncertain of its detrimental effect on the embryo development it should not apply routinely but only on selective patient will be benefit from this procedure. This includes:

• Elderly patient with the age of >38.
• Patient with high basal FSH level.
• Patient with embryos having thick zona ( shell)
• Patient who have three or more failed embryo transfer.