ICSI
OtherAll patients will receive controlled ovarian hyperstimulation (COH) treatment, which is performed by standard routines at each study center. The COH treatment includes either gonadotrophin-releasing hormone agonist (GnRH-a) protocol or gonadotrophin-releasing hormone antagonist (GnRH-ant) protocol.Oocyte retrieval is scheduled for 36 (±2) after hCG injection.The retrieved cumulus oocyte complexes (COC) will be allocated to undergo routine ICSI procedure according to the result of randomization in each study site.