RESUMEN
Men with non-obstructive azoospermia (NOA) can achieve fertility by testicular sperm extraction (TESE) coupled with intracytoplasmic sperm injection (ICSI), the key to which is the successful retrieval of sperm from the testis. Although improved testicular sperm extraction techniques have increased the chances of sperm retrieval, to predict preoperatively the success of sperm retrieval from NOA patients remains challenging. A non-invasive diagnostic technique predicting the presence of sperm in the testis would be useful for avoiding possible surgical intervention. At present, some preoperative variables, such as serum FSH, inhibin B level, testis volume, genetic analysis, histopathology on diagnostic biopsy, Raman Spectroscopy, and molecular and protein markers, have provided new insights into the chances of successful sperm retrieval in NOA males. This review aims to evaluate the preoperative factors currently available for predicting the outcomes of sperm retrieval from NOA patients.