Electronic cigarettes (e-cigarettes) are often considered a “safe substitute” for conventional cigarette cessation. The composition of the fluid is not always clearly defined and shows a large variation within brands and manufacturers. More than 80 compounds were detected in liquids and aerosols. E-cigarettes contain nicotine, and the addition of flavorings increases the toxicity of e-cigarette vapour in a significant manner. The heat generated by the e-cigarette leads to the oxidation and decomposition of its components, eventually forming harmful constituents in the inhaled vapour. The effects of these toxicants on male and female reproduction are well established in conventional cigarette smokers. Although toxins were measured at much lower levels in e-cigarette aerosols compared to smoke from a conventional cigarette, there are concerns about their potential impact on male and female reproduction. The information available was mainly obtained from studies conducted in animal models, and investigations in humans are scarce. However, the effects observed in animal models suggest that caution should be taken when vaping and that more research needs to be conducted to identify its potential adverse effects on fertility. The prevalence of e-cigarette usage is alarming, and warnings should be made about the impact of vaping on reproductive health. This document reviews the data regarding the impact of e-cigarette use on male and female reproduction.

Oxidative stress is a significant factor in male infertility, with increasing evidence evaluating the role of antioxidants in mitigating its detrimental effects on sperm function and quality. This review examines the mechanisms by which reactive oxygen species (ROS) impact male reproductive health. This article synthesizes the different mechanisms at play and highlights key clinical studies published in the literature that contribute to our understanding of antioxidants to treat male infertility. These studies suggest that supplementation with specific antioxidants may improve sperm parameters and increase fertility outcomes, although results vary depending on dosage, duration, and individual health conditions. Despite promising findings, there are inconsistencies across study methodologies and a lack of standardized treatment protocols, which underscore the need for more rigorous clinical trials. Antioxidant supplementation has the potential to serve as a supportive treatment for male infertility, but it should be approached cautiously and appropriately by carefully selecting patients who are deficient in the administered antioxidants. There is a need to better evaluate the long-term impact on reproductive outcomes and determine the optimal supplementation strategies and patient profiles that would benefit most from supplementation regimens.

The computer-assisted program SiD was developed to assess and select sperm in real time based on motility characteristics. To date, there are limited studies examining the correlation between AI-assisted sperm selection and ICSI outcomes. To address this limit, a total of 646 sibling MII oocytes were randomly divided into two groups as follows: the ICSI group (n = 320): ICSI performed with sperm selected by the embryologist and the ICSI-SiD group (n = 326): ICSI performed with sperm selected using SiD software. Our results show a non-significant trend towards improved outcomes in the ICSI-SiD group across various biological parameters, including fertilization, cleavage, day 3 embryo development, blastocyst development, and quality on day 5. Similarly, we observed a non-significant increase in these outcomes when comparing both groups with sperm selection performed by a junior embryologist. Embryo development was monitored using a timelapse system. Some fertilization events happen significantly earlier when SiD is used for ICSI, but no significant difference was observed in the ICSI-SiD group for other timepoints. We observed comparable cumulative early and clinical pregnancy rates after ICSI-SiD. This preliminary investigation illustrated that employing the automated sperm selection software SiD leads to comparable biological outcomes, suggesting its efficacy in sperm selection.

Background/Objectives: Phospholipase C zeta (PLCZ1; PLCζ) is a sperm-specific enzyme responsible for the Ca²⁺ oscillations required for oocyte activation, and altered PLCζ expression has been associated with fertilization failure in assisted reproductive technologies, particularly intracytoplasmic sperm injection (ICSI). This study aimed to develop and analytically validate a flow cytometry–based protocol for PLCζ quantification in human spermatozoa. Methods: The assay was established using normozoospermic samples and included validated positive and negative technical controls. Antibody specificity was confirmed by Western blot analysis. A defined gating strategy was used to assess linearity between fluorescence intensity and PLCζ expression. Analytical performance was evaluated for precision, reproducibility, stability, and sensitivity, including applicability to low sperm concentrations. Results: A linear relationship between fluorescence intensity and PLCζ expression was demonstrated. The assay showed high precision, reproducibility, and stability, with consistent results in samples stored up to 24 h at room temperature or up to one week post-fixation at 4 °C. Sensitivity testing confirmed suitability for low sperm concentrations. Conclusions: This work provides a standardized and analytically validated framework for PLCζ quantification using flow cytometry. Although the assay measures protein expression rather than functional competence or subcellular localization, it establishes a solid analytical basis for future studies to define clinically relevant PLCζ thresholds and assess its value as a biomarker of fertilization capacity.

This study evaluates ChromaLIVE^TM, a multichromatic, mix-and-read fluorescent marker developed for continuous live-cell imaging, in the context of embryology. The aim was to evaluate whether this marker is compatible with dynamic embryonic development up to the blastocyst stage, with minimal impact on embryo viability, integrity, or normal growth of mouse embryos at the 2-cell stage that were cultured to the blastocyst stage under time-lapse imaging conditions, either in the presence or absence of ChromaLIVE^TM. Results showed comparable blastocyst formation rates between ChromaLive^TM and the control group, as well as similar proportions of high-quality blastocysts. Although minor but statistically significant delays were noted in two kinetics events (t3 and tSB), other developmental timings remained unaffected. Time-lapse confocal fluorescence imaging demonstrated that ChromaLIVE^TM dye provided stable, bright, high-resolution 3D visualizations of cellular compartments including membranes, cytoplasm and embryonic structures such as trophectoderm, inner cell mass and blastocoel throughout development. Finally, transcriptomic analyses revealed a limited set of gene-expression differences between stained and unstained embryos; although these included developmental and metabolic pathways, embryos developed to the blastocyst stage comparably to controls.