Does cryopreservation of sperm affect fertilization in nonobstructive azoospermia or cryptozoospermia?

In cases of cryptozoospermia, frozen-thawed ejaculated sperm is inferior to fresh ejaculated sperm in fertilization rates. However, in nonobstructive azoospermia, no major differences were found between fresh and frozen-thawed testicular sperm. Therefore, uncoupled TESE/oocyte pick-up (OPU) should be considered in NOA cases to prevent possible unnecessary ovarian stimulation and OPU when no sperm cells are detected.