Timing of Oocyte Retrieval and Micro Testicular Sperm Extraction

Inclusion Criteria: * Men who underwent a micro-TESE at the OVO clinic from June 2015 to January 2025. * Patients with non-obstructive azoospermia (NOA), (absence of spermatozoa in multiple semen analyses) * Patients with cryptozoospermia, (presence of a small number of spermatozoa detectable only after semen centrifugation) * Patients with oligoasthenoteratozoospermia (OAT), (sperm concentration of less than 15 million/mL, reduced motility and abnormal morphology) Exclusion Criteria: * Patients who did not have any sperm noted following micro-TESE * Use of donor sperm or oocytes * Frozen sperm or oocytes * Same day oocyte retrieval and sperm extraction * Reversible cause of cryptozoospermia (i.e presence of a varicocele, febrile illness, or recent toxin exposure) Partial genital tract obstruction (i.e post-vaso-vasostomy, post-vasoepididymostomy, and low volume cryptozoospermia with ejaculatory duct obstruction)