The impact of fresh and frozen testicular tissue quality on embryological and clinical outcomes

Reliability of hypo-osmotic swelling test on fresh and frozen-thawed ejaculated or testicular immotile sperm: A sibling oocyte study

The viability of sperm is a crucial factor for achieving a successful pregnancy in intracytoplasmic sperm injection (ICSI) cycles. The aim of this study was to evaluate the accuracy of the hypo-osmotic swelling test (HOST) in fresh and frozen-thawed sperm samples of different origins (ejaculated/testicular). A retrospective analysis was conducted on the outcomes of 2167 oocytes subjected to ICSI using motile and immotile-HOST-positive sperm from 2011 to 2023. We evaluated embryonic development, as well as clinical, obstetric, and neonatal outcomes in four groups based on different sperm origins (ejaculated/testicular) and processing (fresh/frozen). When comparing the results of ICSI between motile and immotile-HOST-positive sperm within each group, it was observed that there were no significant differences in the outcomes for fresh samples. However, for frozen-thawed samples, fertilization rates and blastocyst development rates were significantly lower when ICSI was performed with immotile-HOST-positive sperm compared to motile sperm. Of note, clinical, obstetric, and neonatal outcomes were statistically similar across all groups. Our findings indicate that HOST is more reliable in fresh samples than in those subjected to the freeze-thaw process. Nonetheless, HOST is considered a safe method for selecting viable sperm in all subgroups.

Optimizing outcomes for men with severe infertility

PURPOSE OF REVIEW

To evaluate recent evidence related to optimizing outcomes for men with severe infertility, including effect of ejaculatory abstinence interval on semen parameters and assisted reproductive technology (ART) outcomes, and impact of cryopreservation on surgically retrieved testicular sperm obtained from men with nonobstructive azoospermia (also referred to as azoospermia due to spermatogenic dysfunction).

RECENT FINDINGS

Recent evidence strongly suggests that a short abstinence interval improves sperm motility and ART outcomes. Similarly, recent studies have concluded that using fresh vs. frozen testicular sperm results in higher live birth rates.

SUMMARY

Although the World Health Organization currently recommends a 2- to 7-day ejaculatory abstinence period, this interval is based more on the need to standardize semen parameters than clinical outcomes. In fact, recent evidence suggests that shorter abstinence consistently improves sperm motility and ART outcomes for infertile men. Similarly, recent studies have reported an improvement in live birth rates with fresh (vs. frozen) testicular sperm, though their retrospective design and lack of intention to treat analyses makes it difficult to draw strong conclusions. Although additional, well designed studies are needed, providers may be able to leverage these techniques in their practice to improve outcomes for some infertile men.

Sperm Selection Procedures for Optimizing the Outcome of ICSI in Patients with NOA

Retrieving spermatozoa from the testicles has been a great hope for patients with non-obstructive azoospermia (NOA), but relevant methods have not yet been developed to the level necessary to provide resolutions for all cases of NOA. Although performing testicular sperm extraction under microscopic magnification has increased sperm retrieval rates, in vitro selection and processing of quality sperm plays an essential role in the success of in vitro fertilization. Moreover, sperm cryopreservation is widely used in assisted reproductive technologies, whether for therapeutic purposes or for future fertility preservation. In recent years, there have been new developments using advanced technologies to freeze and preserve even very small numbers of sperm for which conventional techniques are inadequate. The present review provides an up-to-date summary of current strategies for maximizing sperm recovery from surgically obtained testicular samples and, as an extension, optimization of in vitro sperm processing techniques in the management of NOA.