Hormonal markers as noninvasive predictors of sperm retrieval in non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is one of the leading causes of male factor infertility, which results from impaired spermatogenesis. Currently, the sole feasible therapeutic option for men with NOA to father their biologic children is sperm retrieval by testicular sperm extraction (TESE) approaches followed by an intracytoplasmic sperm injection program. Nevertheless, the rate of sperm retrieval from NOA men following TESE has remained as low as 50%, leading to a significant number of unsuccessful TESE operations. Given that TESE is associated with multiple side effects, the prediction of TESE outcome preoperatively can abolish unnecessary operations and thereby prevent NOA patients from sustaining adverse side effects. As the process of spermatogenesis is under the regulation of hormones, the hormonal profile of serum and/or seminal plasma may contain useful information about spermatogenesis status and can potentially predict the chance of sperm retrieval from NOA patients. A large body of literature is available on the predictive capability of different serum and seminal plasma hormones such as FSH, LH, testosterone, inhibin B, AMH, estradiol, prolactin, and leptin in a stand-alone basis or combinational fashion with respect to the TESE outcome. The present review aimed to evaluate the potential of these hormonal markers as noninvasive predictors of sperm retrieval in men with NOA.