What is azoospermia? How should I obtain sperm for assisted reproduction if I have azoospermia? Azoospermia is a serious type of male infertility in which at least two times a sample of ejaculated semen is observed after centrifugal precipitation and no sperms are present in the whole slice microscopy. The prevalence of azoospermia is about 1% in the general population and about 10-15% in infertile couples. Azoospermia is not the same as no sperm. Depending on the cause, azoospermia can be categorized into obstructive azoospermia (OA) and non-obstructive azoospermia (NOA). Patients with obstructive azoospermia often have normal spermatogenesis, and the main cause is the absence of sperm in the semen due to obstruction of the vas deferens, or congenital absence of the vas deferens. Through surgical sperm retrieval, the sperm acquisition rate is close to 100%. In non-obstructive azoospermia, the main cause of the disease is severely impaired or completely absent spermatogenesis in the testes, and the probability of obtaining sperm through surgical sperm retrieval is about 50%. Surgical collection of testicular or epididymal spermatozoa has become the mainstay of assisted reproduction in azoospermia patients. Percutaneous epididymal sperm retrieval, testicular sperm retrieval by puncture and the recently developed testicular microsperm retrieval provide a chance for azoospermic patients to have children. Percutaneous epididymal sperm aspiration (PESA) is mainly used in patients with irreversible obstructive azoospermia, such as multiple obstructions and congenital anomalies or deficiencies of the vas deferens as well as in those who have failed to undergo recanalization after vasectomy. Some PESAs are scheduled on the same day as the egg retrieval procedure, and the sperm retrieved during the procedure is subjected to intracytoplasmic monosperm microinjection (ICSI), while the remaining sperm can be frozen and stored for later use. Some PESAs are scheduled weeks or months before the egg retrieval procedure and all samples are frozen for use on the day of the procedure, avoiding the need to freeze eggs on the day of the procedure when no sperm can be retrieved. The advantages of PESA are that the procedure is easy and less invasive, and the epididymal sperm are more mature than testicular sperm. Sperm obtained during the operation can be used directly for intracytoplasmic monosperm microinjection, which can result in a higher fertilization rate and a more satisfactory pregnancy outcome. Testicular aspiration sperm retrieval (TESA) Indications for testicular sperm retrieval include non-obstructive azoospermia as well as patients with obstructive azoospermia in whom no available sperm are found in the epididymis. Sperm obtained directly from the testes are immature because sperm mature in the epididymis. Sperm taken from the testes are weak or even inactive. The final maturation of the spermatozoa with motility is accomplished throughout the transport process after it is detached from the testicular tissue. Recently, however, it has been suggested that since testicular spermatozoa have less DNA damage than spermatozoa in the semen and epididymis, patients with recurrent implantation failures that are suspected to be related to DNA damage in the semen or epididymis spermatozoa may be considered for collection of testicular spermatozoa for intracytoplasmic sperm microinjection in order to achieve a better pregnancy outcome. Testicular microsperm harvesting Testicular microsperm harvesting allows patients with non-obstructive azoospermia to obtain a sufficient number of spermatozoa by cutting a minimal amount of testicular tissue. Testicular microsperm retrieval allows the isolation of focal varicocele in patients with non-obstructive azoospermia under direct visualization, as if searching for an oasis in a desert. Sperm acquisition rates tend to be higher, less damaging, and with a lower complication rate than traditional testicular sperm retrieval. The key to microscopic sperm retrieval is to microscopically locate the seminiferous tubules where sperm are present, however, due to the subjective nature of the selection, success in obtaining sperm is not always guaranteed. In summary, the goal of surgical sperm retrieval is to obtain sperm in sufficient quantity and quality for assisted reproductive technology or cryopreservation, while minimizing damage to the reproductive organs. Regardless of the type of sperm retrieval procedure used, the sperm obtained is combined with intracytoplasmic monosperm microinjection in order to give the patient a high fertilization rate as well as an optimal pregnancy outcome.