Azoospermia is characterized by the absence of sperm in the ejaculate and is categorized into obstructive azoospermia (OA) and nonobstructive azoospermia (NOA). For men with NOA, testicular sperm extraction (TESE) is the only method to obtain sperm for assisted reproductive technology (ART). Given the rarity of these sperm and the unpredictable success of subsequent retrieval attempts, cryopreservation of microdissection-TESE-obtained sperm is essential. Effective cryopreservation prevents the need for repeated surgical procedures and supports future ART attempts. After first delving into the physiological and molecular aspects of sperm cryopreservation, this review aims to examine the current methods and devices for preserving small numbers of sperm. It presents conventional freezing and vitrification techniques, evaluating their respective strengths and limitations in effectively preserving rare sperm, and compares the efficacy of using fresh versus cryopreserved testicular sperm.
Humans ; Cryopreservation/methods* ; Male ; Sperm Retrieval ; Azoospermia/therapy* ; Semen Preservation/methods* ; Spermatozoa ; Vitrification

Hypogonadotropic hypogonadism (HH) represents a relatively rare cause of nonobstructive azoospermia (NOA), but its knowledge is crucial for the clinical andrologists, as it represents a condition that can be corrected with medical therapy in 3 quarters of cases. There are forms of congenital HH, whether or not associated with an absent sense of smell (anosmic HH or Kallmann syndrome, and normosmic HH, respectively), and forms of acquired HH. In congenital HH, complete absence of pubertal development is characteristic. On the other hand, if the deficit occurs after the time of pubertal development, as in acquired HH patients, infertility and typical symptoms of late-onset hypogonadism are the main reasons for seeking medical assistance. Gonadotropin-releasing hormone (GnRH) or gonadotropin replacement therapy is the mainstay of drug therapy and offers excellent results, although a small but significant proportion of patients do not achieve sufficient responses.
Humans ; Hypogonadism/drug therapy* ; Male ; Azoospermia/drug therapy* ; Gonadotropin-Releasing Hormone/therapeutic use* ; Kallmann Syndrome/drug therapy* ; Hormone Replacement Therapy

Except in cases of hypogonadotropic hypogonadism, the use of medical therapy before microsurgical testicular sperm extraction (micro-TESE) is controversial. In some studies, hormone therapy has been shown to improve the possibility of sperm retrieval during micro-TESE and even lead to the presence of sperm in the ejaculate in some cases, thereby obviating the need for micro-TESE. However, their routine use before micro-TESE in cases of nonobstructive azoospermia (NOA) being associated with hypergonadotropic hypogonadism and eugonadism (normogonadotropic condition) has not been supported with robust evidence. In this review, we discuss different types of medical therapy used before micro-TESE for NOA, their risks and benefits, and the available evidence surrounding their use in this setting.
Humans ; Male ; Azoospermia/therapy* ; Sperm Retrieval ; Hypogonadism/complications* ; Microsurgery

Azoospermia, defined as the absence of sperm in the ejaculate, is a well-documented consequence of exogenous testosterone (ET) and anabolic-androgenic steroid (AAS) use. These agents suppress the hypothalamic-pituitary-gonadal (HPG) axis, leading to reduced intratesticular testosterone levels and impaired spermatogenesis. This review examines the pathophysiological mechanisms underlying azoospermia and outlines therapeutic strategies for recovery. Azoospermia is categorized into pretesticular, testicular, and post-testicular types, with a focus on personalized treatment approaches based on the degree of HPG axis suppression and baseline testicular function. Key strategies include discontinuing ET and monitoring for spontaneous recovery, particularly in patients with shorter durations of ET use. For cases of persistent azoospermia, gonadotropins (human chorionic gonadotropin [hCG] and follicle-stimulating hormone [FSH]) and selective estrogen receptor modulators (SERMs), such as clomiphene citrate, are recommended, either alone or in combination. The global increase in exogenous testosterone use, including testosterone replacement therapy and AAS, underscores the need for improved management of associated azoospermia, which can be temporary or permanent depending on individual factors and the type of testosterone used. Additionally, the manuscript discusses preventive strategies, such as transitioning to short-acting testosterone formulations or incorporating low-dose hCG to preserve fertility during ET therapy. While guidelines for managing testosterone-related azoospermia remain limited, emerging research indicates the potential efficacy of hormonal stimulation therapies. However, there is a notable lack of well-structured, controlled, and long-term studies addressing the management of azoospermia related to exogenous testosterone use, highlighting the need for such studies to inform evidence-based recommendations.
Humans ; Azoospermia/therapy* ; Male ; Testosterone/therapeutic use* ; Anabolic Agents/adverse effects* ; Clomiphene/therapeutic use* ; Chorionic Gonadotropin/therapeutic use* ; Follicle Stimulating Hormone/therapeutic use* ; Spermatogenesis/drug effects* ; Androgens/adverse effects*

Oncological microdissection testicular sperm extraction (onco-micro-TESE) represents a significant breakthrough for patients with nonobstructive azoospermia (NOA) and a concomitant in situ testicular tumor, to be managed at the time of sperm retrieval. Onco-micro-TESE addresses the dual objectives of treating both infertility and the testicular tumor simultaneously. The technique is intricate, necessitating a comprehensive understanding of testicular anatomy, physiology, tumor biology, and advanced microsurgical methods. It aims to carefully extract viable spermatozoa while minimizing the risk of tumor dissemination. This review encapsulates the procedural intricacies, evaluates success determinants, including tumor pathology and spermatogenic tissue health, and discusses the implementation of imaging techniques for enhanced surgical precision. Ethical considerations are paramount, as the procedure implicates complex decision-making that weighs the potential oncological risks against the profound desire for fatherhood using the male gametes. The review aims to provide a holistic overview of onco-micro-TESE, detailing methodological advances, clinical outcomes, and the ethical landscape, thus offering an indispensable resource for clinicians navigating this multifaceted clinical scenario.
Humans ; Male ; Azoospermia/therapy* ; Testicular Neoplasms/pathology* ; Sperm Retrieval ; Microdissection/methods* ; Testis/surgery*

The use of fresh versus frozen spermatozoa in men with nonobstructive azoospermia (NOA) undergoing in vitro fertilization (IVF) has been a debated hot topic among reproductive specialists. Each approach presents distinct advantages and disadvantages, with fresh sperm typically showing superior sperm quality, while frozen sperm offers logistical flexibility and a reliable backup for repeated cycles. This review summarizes the latest advancements in sperm retrieval and cryopreservation techniques, providing practitioners with a comprehensive analysis of each option's strengths and limitations. Comparative studies indicate that, although fresh sperm often has better quality metrics, cryopreservation methods such as vitrification have significantly improved postthaw outcomes, making frozen sperm a viable choice in assisted reproductive technologies (ART). The findings show comparable rates for fertilization, implantation, clinical pregnancy, and live birth between fresh and frozen microdissection testicular sperm extraction (micro-TESE) sperm in many cases, although patient-specific factors such as timing, cost-effectiveness, and procedural convenience should guide the final decision. Ultimately, the choice of using fresh or frozen sperm should align with the individual needs and conditions of patients. This tailored approach, supported by the latest advancements, can optimize ART outcomes and provide personalized reproductive care.
Humans ; Cryopreservation/methods* ; Male ; Sperm Retrieval ; Semen Preservation/methods* ; Azoospermia/therapy* ; Pregnancy ; Female ; Fertilization in Vitro ; Spermatozoa ; Microdissection ; Pregnancy Rate

This review focuses on the diagnostic algorithm for nonobstructive azoospermia (NOA), a significant male factor contributing to infertility. NOA, characterized by the absence of sperm in the ejaculate, requires a systematic diagnostic approach to identify reversible conditions, genetic factors, and prognosis for achieving pregnancy. The diagnostic pathway involves semen analysis and a comprehensive evaluation for hormonal deficiencies, anatomical abnormalities, and genetic factors. The importance of medical history, physical examination, endocrine evaluation, imaging, and genetic testing is emphasized. This review highlights the significance of differentiating NOA from obstructive azoospermia (OA) and outlines key considerations for effective management, including surgical sperm retrieval and assisted reproductive techniques. Testicular biopsy is discussed as a definitive method to distinguish obstructive cases from nonobstructive cases, providing valuable prognostic information. Overall, a thorough and systematic diagnostic approach is essential for the effective management of men suspected with NOA, offering insights into potential treatment options and reproductive outcomes.
Humans ; Azoospermia/therapy* ; Male ; Algorithms ; Semen Analysis ; Testis/pathology* ; Sperm Retrieval ; Biopsy ; Infertility, Male/etiology*

Infertility affects 10%-15% of couples worldwide. Of all infertility cases, 20%-70% are due to male factors. In the past, men with severe male factor (SMF) were considered sterile. Nevertheless, the development of intracytoplasmic sperm injection (ICSI) drastically modified this scenario. The advances in assisted reproductive technology (ART), specifically regarding surgical sperm retrieval procedures, allowed the efficacious treatment of these conditions. Yet, before undergoing ICSI, male factor infertility requires careful evaluation of clinical and lifestyle behavior together with medical treatment. Epidemiologically speaking, women whose male partner is azoospermic tend to be younger and with a better ovarian reserve. These couples, in fact, are proposed ART earlier in their life, and for this reason, their ovarian response after stimulation is generally good. Furthermore, in younger couples, azoospermia can be partially compensated by the efficient ovarian response, resulting in an acceptable fertility rate following in vitro fertilization (IVF) techniques. Conversely, when azoospermia is associated with a reduced ovarian reserve and/or advanced maternal age, the treatment becomes more challenging, with a consequent reduction in IVF outcomes. Nonetheless, azoospermia seems to impair neither the euploidy rate at the blastocyst stage nor the implantation of euploid blastocysts. Based on the current knowledge, the assessment of male infertility factors should involve: (1) evaluation - to diagnose and quantify seminologic alterations; (2) potentiality - to determine the real possibilities to improve sperm parameters and/or retrieve spermatozoa; (3) time - to consider the available "treatment window", based on maternal age and ovarian reserve. This review represents an update of the definition, prevalence, causes, and treatment of SMF in a modern ART clinic.
Azoospermia ; Female ; Fertilization in Vitro/methods* ; Humans ; Infertility, Male/therapy* ; Male ; Prevalence ; Reproductive Techniques, Assisted ; Sperm Injections, Intracytoplasmic/methods* ; Spermatozoa

Azoospermia/therapy* ; Female ; Humans ; Male ; Microdissection ; Pregnancy ; Pregnancy Rate ; Retrospective Studies ; Sperm Injections, Intracytoplasmic ; Sperm Motility ; Sperm Retrieval ; Spermatozoa ; Testis

The extent of spermatogenic impairment on intracytoplasmic sperm injection (ICSI) outcomes and the risk of major birth defects have been little assessed. In this study, we evaluated the relationship between various spermatogenic conditions, sperm origin on ICSI outcomes, and major birth defects. A total of 934 infertile men attending the Center for Reproductive Medicine of Ren Ji Hospital (Shanghai, China) were classified into six groups: nonobstructive azoospermia (NOA; n = 84), extremely severe oligozoospermia (esOZ; n = 163), severe oligozoospermia (sOZ, n = 174), mild oligozoospermia (mOZ; n = 148), obstructive azoospermia (OAZ; n = 155), and normozoospermia (NZ; n = 210). Rates of fertilization, embryo cleavage, high-quality embryos, implantation, biochemical and clinical pregnancies, abortion, delivery, newborns, as well as major birth malformations, and other newborn outcomes were analyzed and compared among groups. The NOA group showed a statistically lower fertilization rate (68.2% vs esOZ 77.3%, sOZ 78.0%, mOZ 73.8%, OAZ 76.6%, and NZ 79.3%, all P < 0.05), but a significantly higher implantation rate (37.8%) than the groups esOZ (30.1%), sOZ (30.4%), mOZ (32.6%), and OAZ (31.0%) (all P < 0.05), which was similar to that of Group NZ (38.4%). However, there were no statistically significant differences in rates of embryo cleavage, high-quality embryos, biochemical and clinical pregnancies, abortions, deliveries, major birth malformations, and other newborn outcomes in the six groups. The results showed that NOA only negatively affects some embryological outcomes such as fertilization rate. There was no evidence of differences in other embryological and clinical outcomes with respect to sperm source or spermatogenic status. Spermatogenic failure and sperm origins do not impinge on the clinical outcomes in ICSI treatment.
Azoospermia/therapy* ; China ; Female ; Humans ; Infant, Newborn ; Male ; Oligospermia/therapy* ; Pregnancy ; Pregnancy Rate ; Retrospective Studies ; Sperm Injections, Intracytoplasmic/methods* ; Sperm Retrieval ; Spermatogenesis ; Spermatozoa