Objective:To evaluate the laboratory performance of a standardized gradient-based sperm preparation system designed to improve progressive motility recovery during density gradient centrifugation for intrauterineinsemination (IUI). Design:Retrospective, multicenter laboratory cohort study. Patients:A total of 13,416 semen samples processed for IUI. Interventions:Comparison between a conventional density gradient centrifugation method and a standardized gradient-based preparation system (RS system)...Read More

In animals, mature sperm are stored in males before ejaculation and sometimes in females before fertilization. Sperm storage provides evolutionary advantages; however, storage can also cause sperm deterioration owing to post-meiotic sperm senescence (PMSS). Yet, the extent of such deterioration, the mechanisms driving it and its fitness consequences remain poorly understood. We perform a meta-...Read More

One-third of infertile couples struggle to conceive despite normal examination and tests. For men, semen analysis is the only widely-adopted diagnostic tool to assess male infertility. However, it is unable to detect abnormal sperm function or accurately predict pregnancy except in cases of complete absence of sperm. Sperm function tests (SFT) could help by directing...Read More

Segregation distortion, the disproportionate inheritance of selfish genetic elements, is an important evolutionary force. While many species carry distorters, it is not clear if humans do. Major limitations for detecting human distortion are the small size of human families and the lack of genetic markers in most subjects. Here, we present evidence of strong distortion...Read More

The mammalian spermatozoon neck is a unique structure that functions during spermatid differentiation and spermatozoa swimming, and its contents are critical for post-fertilization embryogenesis. Mutations in proteins localizing to the neck connecting piece (the modified pericentriolar material) result in acephalic spermatozoa. In contrast, mutations in proteins localizing to the centriole often produce abnormal tail morphology....Read More

Recurrent pregnancy loss (RPL) is a condition affecting up to 5% of couples. We conducted a systematic review and meta-analysis (SRMA) to synthesize the evidence on the relationship between seminal oxidative stress (OS) and RPL. This study aimed to evaluate whether seminal OS markers differ between men from couples experiencing RPL and those from fertile...Read More

Sperm and pusher eukaryotic cells achieve locomotion through a complex interaction between their flagellar movement and the surrounding fluid. The flagellar waveform arises from a balance of dynein-driven cytoskeletal forces, passive structural resistance, and hydrodynamic drag. However, the underlying mechanisms of cell-fluid interactions remain poorly understood due to the limitations of current measurement techniques. Here,...Read More

According to these extensive Danish data, if your total motile sperm count is <5 × 106/ml you can expect to live for 77.6 years, whereas if you are lucky enough to possess a count of >120 × 106/ml, your life expectancy will increase to 80.3 years. This is encouraging for those so endowed, although they will still be dying 3 years before...Read More

Male infertility and semen quality have been suggested to be markers of morbidity and thus mortality, but the role of underlying disease present at time of semen quality evaluation has not been thoroughly assessed. The aim of this study was to determine the association between semen quality and mortality, and to assess the impact of...Read More

The objective of this study was to evaluate the impact of basic semen analysis parameters, assessed according to WHO-2021 criteria, as well as paternal BMI and paternal age on embryological and clinical ICSI outcomes among couples undergoing preimplantation genetic testing for aneuploidy (PGT-A). Our main goal is to provide IVF professionals with information about the...Read More