Several studies indicate that semen quality has strongly declined in the last decades worldwide. Air pollution represents a significant co-factor with the COVID-19 impact and has negative effects on the male reproductive system, through pro-oxidant, inflammatory and immune-dysregulating mechanisms. It has recently been reported that chronic exposure to PM2.5 causes overexpression of the alveolar ACE2 receptor, the entry route of SARS-CoV-2 into the organism shared by the lungs and testis where expression is highest in the body. In the testis, the ACE2/Ang-(1–7)/MasR pathway plays an important role in the regulation of spermatogenesis and an indirect mechanism of testicular damage could be due to the blockade of the ACE2 receptor by SARS-CoV-2. This prevents the conversion of specific angiotensins, and their excess causes inflammation with the overproduction of cytokines. PM2.5-induced overexpression of the alveolar ACE2 receptor, in turn, could increase local viral load in patients exposed to pollutants, producing ACE2 receptor depletion and compromising host defenses. By presenting an overall view of epidemiological data and molecular mechanisms, this manuscript aims to interpret the possible synergistic effects of both air pollution and COVID-19 on male reproductive function, warning that the spread of SARS-CoV-2 in the fertile years may represent a significant threat to global reproductive health. All of this should be of great concern, especially for men of the age of maximum reproductive capacity, and an important topic of debate for policy makers. Altered environmental conditions, together with the direct and indirect short- and long-term effects of viral infection could cause a worsening of semen quality with important consequences for male fertility, especially in those areas with higher environmental impact.

The epidemic of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has impacted worldwide with its infectious spread and mortality rate. Thousands of articles have been published to tackle this crisis and many of these have indicated that high air pollution levels may be a contributing factor to high outbreak rates of COVID-19. Atmospheric pollutants, indeed, producing oxidative stress, inflammation, immuno-unbalance, and systemic coagulation, may be a possible significant co-factor of further damage, rendering the body prone to infections by a variety of pathogens, including viruses. Spermatozoa are extremely responsive to prooxidative effects produced by environmental pollutants and may serve as a powerful alert that signals the extent that environmental pressure, in a specific area, is doing damage to humans. In order to improve our current knowledge on this topic, this review article summarizes the relevant current observations emphasizing the weight that environmental pollution has on the sensitivity of a given population to several diseases and how semen quality, may be a potential indicator of sensitivity for virus insults (including SARS-CoV-2) in high polluted areas, and help to predict the risk for harmful effects of the SARS-CoV-2 epidemic. In addition, this review focused on the potential routes of virus transmission that may represent a population health risk and also identified the areas of critical importance that require urgent research to assess and manage the COVID-19 outbreak.

The intracytoplasmic sperm injection (ICSI) technique was invented to solve severe male infertility due to altered sperm parameters. Nowadays, it is applied worldwide for the treatment of couple infertility. ICSI is performed with any available spermatozoon from surgery or ejaculated samples, whatever are the sperm motility, morphology or quantity. The aim of the present review was to study if embryo development and kinetics would be modified by (1) ICSI under the technical aspects, (2) the micro-injected spermatozoa in connection with male infertility. From published data, it can be seen that ICSI anticipates the zygote kinetics Furthermore, because fertilization rate is higher in ICSI compared to conventional in vitro fertilization (IVF), more blastocysts are obtained for clinical use in ICSI. Sperm and spermatozoa characteristics, such as sperm parameters, morphology and vitality, DNA content (levels of sperm DNA fragmentation, microdeletions, and chromosomal abnormalities), RNA content, epigenetics, and sperm recovery site (testicular, epididymis, and ejaculated), have an impact on fertilization and blastocyst rates and embryo kinetics in different ways. Even though ICSI is the most common solution to solve couples’ infertility, the causes of male infertility are crucial in building a competent spermatozoa that will contribute to normal embryonic development and healthy offspring.

Background and Objectives: The Mediterranean diet is traditionally linked to metabolic balance and improved reproductive health. However, dietary patterns in Mediterranean regions have progressively shifted toward more Westernized models, particularly among women of reproductive age, raising concerns about declining adherence to this historically protective diet. Objective: To assess adherence to the Mediterranean diet among women undergoing assisted reproductive technology (ART) and to explore possible associations with ovarian response and clinical outcomes. Materials and Methods: This prospective observational cohort study was conducted at a reproductive clinic in Sicily between 1 June and 31 July 2022. One hundred women aged 18–40 years undergoing infertility assessment and scheduled for controlled ovarian stimulation were enrolled. Mediterranean diet adherence was evaluated using the validated 14-item MEDAS questionnaire during the first clinical visit. ART-related outcomes, including ovarian response and pregnancy rates, were extracted from medical records. Results: The mean MEDAS score was 7.6 ± 1.2: 93% of women showed moderate adherence, 3% high adherence, and 4% low adherence. No significant associations were found between MEDAS score, and total oocytes retrieved, MII oocytes, or clinical pregnancy. Conclusions: Despite living in a traditionally Mediterranean area, participants demonstrated only moderate adherence to the Mediterranean diet. Although no associations with single-cycle ART outcomes emerged, the findings underscore the need for structured nutritional counseling to reinforce sustained adherence and support long-term reproductive health.

High levels of air pollution can contribute to high rate of the COVID-19 outbreaks. Air pollutants induce oxidative stress, inflammatory process, immune imbalance and coagulation at systemic level, making the organism susceptible to complications caused by various pathogens, including viruses, resulting in a possible important damage co-factor. Sperm cells are highly sensitive to the pro-oxidant effects of environmental pollutants, and may represent an important alarm bell indicating that the burden of environmental pressure in a certain area is causing damage to humans. A comparison of the maps of COVID-19 case fatality rates, male infertility rates and air pollution may suggest a way to understand the dynamics of the virus impact. Semen quality may be considered as an early and sensitive environmental marker, and also a potential susceptibility indicator to viral insults (including SARS-CoV-2 ) in heavily polluted areas. Therefore, assessing the burden of environmental exposure of a given population and its potential susceptibility to insults through early biological stress indicators may be helpful for predicting the risk of the adverse effects by the SARS-CoV-2 epidemic .