Decline of semen quality over the last 30 years in Uruguay.

BACKGROUND: Over the last years, there has been an increasing concern about a global decline in men's fertility. Specifically, some evidence indicates that sperm quality has decreased over the last years. However, reports showing the changes in sperm quality with time are inconsistent. Part of the contradictions between studies is attributed to geographical differences. Surprisingly, few studies include data from South American countries, creating a bias in the conclusions. This study aims to determine how sperm quality has evolved over the past 30 years in Uruguay. For this purpose, 317 medical records from allegedly healthy sperm donor candidates, aged between 18 and 36 years old, who voluntarily requested to be considered as sperm donors between 1988 and 2019, were analyzed. The studied variables were the following sperm parameters: semen volume, sperm cell concentration, total sperm number, progressive motility, vitality, and sperm morphology. A correlative statistical analysis was performed between seminal parameter values and the year data were collected. RESULTS: We found a statistically significant decrease in sperm concentration and normal sperm morphology during the studied period. There was no decrease in vitality, seminal volume, and total progressive motility. Semen parameters were not associated with tobacco, drugs, or alcohol consumption. CONCLUSIONS: We conclude that the sperm quality of donor candidates in Uruguay decreased during this period. Further studies should be carried out to verify the occurrence of this phenomenon in the general population and find its possible causes.

RéSUMé: CONTEXTE: Au cours des dernières années, on s'est de plus en plus inquiété d'une baisse de la fertilité masculine. Plus précisément, certaines données indiquent que la qualité du sperme a diminué au cours des dernières années. Cependant, les rapports montrant les changements dans la qualité du sperme avec le temps sont incohérents. Une partie des contradictions entre les études est attribuée à des différences géographiques. Étonnamment, peu d'études ont inclue des données provenant de pays d'Amérique du Sud, ce qui crée un biais dans les conclusions. Cette étude vise à déterminer comment la qualité du sperme a évolué au cours des 30 dernières années en Uruguay. À cette fin, 317 dossiers médicaux de candidats donneurs de sperme prétendument en bonne santé, âgés de 18 à 36 ans, qui ont volontairement demandé à être considérés comme donneurs de sperme entre 1988 et 2019, ont été analysés. Les variables étudiées étaient les paramètres suivants du sperme: volume de sperme, concentration de cellules spermatiques, nombre total de spermatozoïdes, motilité progressive, vitalité, et morphologie des spermatozoïdes. Une analyse statistique corrélative a été effectuée entre les valeurs des paramètres séminaux et l'année de recueil des données. RéSULTATS: Nous avons trouvé une diminution statistiquement significative de la concentration de spermatozoïdes et de la morphologie normale des spermatozoïdes pendant la période étudiée. Il n'y a eu aucune diminution de la vitalité, du volume de sperme, et de la motilité progressive totale. Les paramètres du sperme n'étaient pas associés à la consommation de tabac, de drogues ou d'alcool. CONCLUSIONS: Nous concluons que la qualité du sperme des candidats donneurs en Uruguay a diminué au cours de cette période. D'autres études devraient être menées pour vérifier l'apparition de ce phénomène dans la population générale et en trouver les causes possibles.

The Uruguayan semen donor population: A twenty-eight-year retrospective study.

Several studies have reported a global decline in seminal quality over the years. The objective of this study was to describe the semen donor population of Uruguay through comparing data of successive samples banked by the same donors and the analysis of their semen and physical characteristics, ancestry origin and educational level. A total of 3,449 ejaculated samples collected from 71 donors, cryobanked between 1989 and March 2017 at Fertilab, were analysed. Results revealed a mean age of 23.90 ± 3.98 years, an average weight of 74.95 ± 1.09 kg and a mean height of 1.78 ± 0.06 m. The majority of the donors trace their origin to Europe (74.65%, 53/71) and 66.19% (47/71) have a level of education higher than secondary school. We observed longitudinal differences in two parameters, that is sperm concentration and semen volume. Sperm concentration declined, while semen volume increased significantly over the 28-year period. The results of the present study are in accordance with that of previous articles that also reported a decline in sperm concentration over time. However, no differences were observed in total sperm number per ejaculate due to the increase in semen volume values, thus reflecting no real changes in sperm production over time.

Impact of delipidated estrous sheep serum supplementation on in vitro maturation, cryotolerance and endoplasmic reticulum stress gene expression of sheep oocytes.

High lipid content of oocytes and embryos in domestic animals is one of the well-known factors associated with poor cryosurvival. Herein, we wanted to determine whether the use of delipidated estrous sheep serum during in vitro maturation (IVM) of ovine oocytes reduces the cytoplasmic lipid droplets content and improves embryo development and cryotolerance after vitrification. Cumulus oocytes complexes (COCs) were matured in vitro for 24 h in medium supplemented with whole or delipidated estrous sheep serum prior to vitrification. Neutral lipid present in lipid droplets of COCs, cleavage rate, embryo development rate on Day 6 and Day 8, and hatching rate on Day 8, were compared among experimental groups. Endoplasmic reticulum stress genes were evaluated in in vitro matured COCs under different lipid conditions prior to vitrification. The lipid droplets' content (mean fluorescence intensity) of oocytes cultured with IVM media supplemented with delipidated serum was lower than COCs matured with whole serum (7.6 ± 1.7 vs. 22.8 ± 5.0 arbitrary units, respectively; P< 0.05). Despite IVM treatment, oocytes subjected to vitrification showed impaired competence compared with the non-vitrified groups (P<0.05). No significant differences in embryo production were observed in non-vitrified COCs after maturation in delipidated or whole serum (33.4±4.9 vs 31.9 ±4.2). COCs matured in delipidated serum and subjected to vitrification showed increased expression of ATF4, ATF6, GRP78, and CHOP10 genes (ER stress markers). Collectively, our results demonstrate that although supplementation of IVM medium with delipidated estrous sheep serum reduces the presence of cytoplasmic lipid droplets in oocytes after maturation, oocyte cryotolerance is not improved. Notably, the expression of genes associated with the unfolded protein response (UPR) was increased in COCs, with fewer lipid droplets subjected to vitrification, suggesting that oocyte cryopreservation is associated with ER stress and activation of adaptive responses.

A retrospective study on sperm banking: a Uruguayan experience.

OBJECTIVE: The purpose of this study was to investigate the status of homologous sperm banking in Uruguay. METHODS: A retrospective investigation was performed on data collected between 2013 and 2015. Reasons for sperm banking, patient age, pre-freeze and post-thaw semen parameters, and recovery rates were analyzed. RESULTS: 623 samples were cryobanked between 2013 and 2015. Only 324 samples were considered for analysis after selection based on inclusion criteria. In most cases the samples were stored because the patients were undergoing assisted reproductive technology (ART) treatment (n=190; 58,64%) or for oncological reasons (n=113; 34,88%). The median age of bankers was 34 years. In the cancer group, 61.95% (n=70) of the subjects had been diagnosed with testicular cancer. Medians of semen parameters for both groups were above the lower reference limits dictated by the . In fresh samples, a significant difference was observed in progressive motility (47% vs. 56%) between ART and oncological patients. After thawing, total motility (27% vs. 32%), progressive motility (19% vs. 22%), and vitality (48% vs. 56%) differed significantly between ART and oncological bankers. CONCLUSION: Semen banking has been performed successfully in Uruguay and outcomes are on par with international standards. Surprisingly, the semen parameters of the cancer group were nearly normal.

Physically active men show better semen parameters and hormone values than sedentary men.

Physical exercise promotes many health benefits. The present study was undertaken to assess possible semen and hormone differences among physically active (PA) subjects and sedentary subjects (SE). The analyzed qualitative sperm parameters were: volume, sperm count, motility, and morphology; where needed, additional testing was performed. The measured hormones were: follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), cortisol (C), and the ratio between T and C (T/C). Maximum oxygen consumption was also assessed to check for differences in fitness level. Statistically significant differences were found for several semen parameters such as total progressive motility (PA: 60.94 ± 5.03; SE: 56.07 ± 4.55) and morphology (PA: 15.54 ± 1.38, SE: 14.40 ± 1.15). The seminological values observed were supported by differences in hormones, with FSH, LH, and T being higher in PA than in SE (5.68 ± 2.51 vs. 3.14 ± 1.84; 5.95 ± 1.11 vs. 5.08 ± 0.98; 7.68 ± 0.77 vs. 6.49 ± 0.80, respectively). Likewise, the T/C ratio, index of anabolic versus catabolic status, was also higher in PA (0.46 ± 0.11 vs. 0.32 ± 0.07), which further supports the possibility of an improved hormonal environment. The present study shows that there are differences in semen and hormone values of physically active subjects and sedentary subjects. Physically active subjects seem to have a more anabolic hormonal environment and a healthier semen production.