The Effect of Laser-assisted Zona Thinning on the Implantation Rate in the Women of Advanced Age

Inclusion Criteria: * Age: 35y ≤age≤46y * Basal FSH value: FSH≤10IU/L * Day-3 embryos transferred in the fresh IVF/ICSI cycles * the number of embryos available to be transferred on Day-3: ≥one embryo Exclusion Criteria: * cycles with thawed/warmed embryos biopsied for PGD/PGS. * cycles with oocyte donation transfer. * the maximum number of previous unsuccessful IVF attempts: ≥ 3 cycles(transfer cycles) * any cycles with the risk of OHSS, fluid in the uterine cavity, abnormal endometrium, uterine abnormalities,pelvic inflammation, and other acute maternal problems. * One or both spouses have an abnormal karyotype (including polymorphism)