Nowadays, sperm cryopreservation is strongly recommended in cases of malignancy. Moreover, the use of frozen testicular sperm in azoospermic patients prevents the need for repeated sperm retrieval and optimises scheduling between oocyte and sperm obtainment. Even though cryopreservation of human spermatozoa for assisted reproductive purposes is a widely implemented practice, none of the established freezing and vitrification techniques offer optimal cryosurvival results due to the dramatic impact of cryodamage on sperm cells. This comprehensive review describes the most commonly used sperm cryopreservation techniques in order to establish which of them minimise sperm cryodamage and offer better survival rates. Presently, it is not sufficiently demonstrated that sperm vitrification improves survival significantly more than freezing methods. Slow freezing offers the best survival results when compared to other freezing protocols, and owing to its technical advantages, can be considered as one of the preferred protocols to be easily implemented in assisted reproduction laboratories. Moreover, several studies have suggested that sperm preparation prior to cryopreservation can improve thawed sample quality. However, other authors have demonstrated that freezing the fresh sample and performing semen preparation after thawing gives better results in regard to total motile sperm count and motility. Regarding clinical results, it is well established that similar or even better reproductive outcomes are achieved using frozen testicular sperm in cases of azoospermia or anejaculation. Moreover, the use of frozen semen in cancer patients can help to achieve good fertilisation and pregnancy rates. Finally, the use of frozen sperm is not at all associated with worse post-natal development.
Sperm cryopreservation has been widely used for assisted reproductive technology (ART). Indications for sperm cryopreservation include donor insemination, cryopreservation prior to surgical infertility treatment, and malignancies to avoid additional surgery in couples undergoing repeated in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles. However, dramatic changes during cryopreservation have detrimental effects on the sperm membrane, resulting in a large increase in the percentage of poorly motile sperm or sperm with abnormal morphology. The negative effects related to rapid temperature decrease, such as osmotic injury, cellular dehydration, intracellular ice crystal formation, and oxidative stress can also damage the sperm in ways that affect reproductive outcome. This comprehensive review focusses on describing the detrimental effects of the cryopreservation process on sperm and aims to clarify that not all impaired sperm parameters have the same impact on the clinical practice of ART. Regarding the parameters studied, some of the biomarkers used for sperm maturity, hyaluronic acid binding capacity, or damaged DNA have limited clinical significance compared to other semen parameters which provide more useful information for clinical practice and are often dismissed, such as total motility or total motile sperm count (TMSC). In the authors’ experience, TMSC gives valuable quantitative information about the number of viable spermatozoa. Indeed, TMSC should be assessed specifically for groups of patients in which sample availability is limited.
Context: Some vaginal lubricants and ultrasound gels are known to be detrimental to sperm function and therefore could negatively affect fertility. Aims: The aim of the current study was to develop a sperm motility index (SMI) to test the sperm toxicity of ultrasound gels and vaginal lubricants used in reproductive medicine. Settings and Design: Two ultrasound gels (Aquasonic ® and Kefus ® ) and five vaginal lubricants (Vaginesil™, Velastisa ® , K-Y Jelly ® , Control ® , and Durex ® ) were studied. Three different concentrations (1%, 5%, and 10%) of each lubricant were tested. Subjects and Methods: SMI was calculated dividing the percentage of progressively motile sperm in each tested gel by that in the control at 0.5, 1, 2, and 24 h of incubation at 5% of CO 2 and 37°C. SMI values <0.75 indicate sperm toxicity. Statistical Analysis Used: The main outcome measured was SMI for each concentration and time of incubation. Results: Only Durex ® did not show any deleterious effect on sperm quality. The rest of lubricants presented different degrees of toxicity. Vaginesil™ resulted in toxic for all concentrations and incubation periods (SMI < 0.12). Control ® and Velastisa ® presented toxicity at 10% after 2 h, while K-Y Jelly ® showed toxicity at 10% from 1 h of incubation. Regarding ultrasound gels, Aquasonic ® showed toxic effects after only 0.5 h (SMI = 0.70 ± 0.15), while Kefus ® showed slightly toxic effects after 2 h (SMI 0.69 ± 0.07). Conclusions: SMI is an accurate tool to evaluate sperm toxicity. One of the main strengths of the article is the inclusion of representative semen samples and known products used worldwide. This study has a relevant clinical translation since it highlights the importance of evaluating the possible sperm toxicity of simple products used in reproductive medicine.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.