All articles tagged with #sperm
Khloé Kardashian reveals on The Cut that Tristan Thompson signed over some of his frozen embryos to her after he had a vasectomy, effectively giving her ownership of his sperm; Thompson says he's done having kids unless they're from Kardashian's embryos, while Kardashian notes she’s preserving sperm for a future possibility, and the couple share two children, True and Tatum.
Cannabis use, especially heavy and chronic use, may impair male fertility by lowering sperm count and mobility and altering reproductive hormones; human studies link cannabis to reduced semen quality, though evidence is mixed; experts say stopping cannabis for at least three months before attempting conception can improve fertility, highlighting that male infertility is common and under‑evaluated.
Chronic stress can disrupt hormones and increase oxidative stress, which may lower sperm count, motility and morphology. Because sperm development takes 2–3 months, prolonged stress can affect future semen samples. It often coexists with poor sleep, weight gain and higher substance use, so fertility is usually multi-factorial. A semen analysis is a common first step; improving sleep (7–9 hours), regular activity, weight management, and reducing nicotine/alcohol can help, alongside medical evaluation for underlying issues.
New microgravity experiments using a tiny obstacle course showed human and mouse sperm navigated about 50% less effectively in space-like conditions, resulting in roughly a 30% drop in fertilization. While some sperm still reach the egg and may form higher-quality embryos, embryo development in weightlessness could pose major challenges, suggesting space reproduction may be possible only for the fittest sperm and with careful embryo protection as NASA pursues Moon and Mars settlements.
Adelaide University researchers tested human, mouse, and pig sperm in a device simulating microgravity, finding that sperm struggled to navigate a maze mimicking the female reproductive tract and showing about a 30% reduction in successful navigation under zero gravity, underscoring gravity as a key factor in early reproductive success during space conditions.
A review of nearly 150 studies finds that regular ejaculation or sex can help sperm quality, while abstinence modestly degrades it via increased oxidative stress and DNA damage, reducing viability and motility in humans and other animals. A recent IVF trial suggested higher fertilization success when men ejaculate within 48 hours of sample collection, though the impact on natural fertility remains unclear. The findings could lead clinics to reassess abstinence guidelines and emphasize sperm quality alongside quantity, while general health benefits of regular sexual activity appear unaffected.
Researchers used a 3D clinostat to simulate microgravity and tested human, pig, and mouse sperm in a channel resembling the female reproductive tract; they found a significant drop in the number of sperm reaching the egg under microgravity, not due to motor changes but impaired direction sensing; fertilization dropped about 30% after four hours of exposure, with longer exposure causing delays and fewer embryos; progesterone could still guide sperm, indicating chemotaxis remains important; the findings, published in Communications Biology, imply spaceflight could affect reproductive outcomes in humans and livestock, highlighting the need for further research.
Australian researchers used a clinostat to simulate microgravity and found human, mouse, and pig sperm become disoriented, with about a 40% drop in those reaching a simulated egg; microgravity also affected early embryo development in animals, though healthy embryos could form, and progesterone helped guide sperm. The findings underscore the importance of understanding reproduction in space for future Moon/Mars settlements and ongoing space biology programs, while noting radiation and ethical considerations remain challenges.
A large meta-analysis across human and non-human studies shows that regular ejaculation helps prevent rapid deterioration of stored sperm, with longer abstinence associated with increased DNA damage and reduced motility. The findings suggest a modest fertility benefit from frequent ejaculation and hint that ejaculation timing could influence IVF success; current guidelines allowing up to seven days between samples may warrant revision.
A study finds that long-term monogamy in termites reduced sperm competition, leading to the loss of sperm-motility genes and enabling a shift from solitary ancestors to highly social colonies, showing that social complexity can arise by pruning genetic complexity.
A new EMBO Journal study reports a mid-life, abrupt shift in sperm RNA—an “aging cliff”—that could influence what fathers pass to their offspring, offering a mechanism beyond DNA mutations that may help explain increased risks of neurodevelopmental and metabolic issues in children of older dads and supporting aging-related cautions in assisted reproduction.
New research shows that harmful genetic mutations in sperm increase with age and are actively favored during sperm production, raising genetic risks for offspring as men grow older, with some mutations linked to serious diseases and cancer, and evidence of natural selection within the testes influencing mutation rates.
A study shows that sperm from older men carry more genetic mutations, including potentially harmful ones, which increases the risk of genetic diseases in offspring. The research highlights that mutations accumulate with age and are subject to positive selection, raising concerns about reproductive planning and genetic counseling for older fathers.
Scientists discovered that human sperm and algae can swim through viscous fluids by exhibiting 'odd elasticity,' which allows them to bypass Newton's third law of motion, revealing non-reciprocal interactions that could inform the design of self-assembling robots and improve understanding of collective biological behavior.
Research shows that as men age, their sperm accumulate more mutations, some of which are harmful and linked to developmental disorders and cancers, increasing the potential health risks for their children. The study highlights the role of 'selfish' mutations that outcompete others in the testes, with mutation rates rising from 2% in men in their 30s to about 4.5% in men over 70, though not all mutations are necessarily passed on or harmful. Further research is needed to understand the full impact on offspring health.