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The relative risk of being born with a major heart defect is 36% in babies conceived using assisted reproductive techniques, such as in vitro fertilisation, compared to newborns not using these techniques, according to a study published in the European Heart Journal. The absolute risk was 1.84% versus 1.15%. The research, which included more than seven million babies born in Denmark, Finland, Norway and Sweden, also shows that the increased risk is especially associated with multiple births, which are more common in assisted reproduction.
 

The sperm of men infected with high-risk genotypes of the human papillomavirus (HPV) suffers more damage from oxidative stress and has a weaker immune response, which can lead to reduced fertility. This is one of the conclusions of a study published in the journal Frontiers in Cellular and Infection Microbiology. The research compared the semen of 20 adults infected with high-risk genotypes, seven infected with low-risk genotypes, and 43 adults without infections.

A new technique developed at the Institut de Bioenginyeria de Catalunya (IBEC) has succeeded in assessing the health of mouse oocytes and embryos in a non-invasive way, according to a study published in PNAS. The method generates 3D images to visualise the metabolism of oocytes and embryos obtained by in vitro fertilisation and makes it possible to select those that are most likely to implant and develop, say the authors.

At an informative meeting organized by the Science Media Centre Spain, the coauthor of a paper published this week in the journal Cell discussed his findings with journalists. Although the study was conducted with mice, he is confident in being able to analyze human eggs to see if his conclusions could explain the loss of fertility that occurs in women with age.

An international team, led by a Spanish group, has published the mechanism that allows immature egg reserves (oocytes) to survive for many years, up to almost half a century in the case of humans. The research studies how oocytes are affected by protein aggregates similar to those that damage other cells such as neurons and can cause neurodegenerative diseases such as Alzheimer's disease. The finding of how these egg reserves are kept healthy may help to understand some causes of infertility. The results are published in the journal Cell.

A team of researchers has demonstrated how a non-invasive ultrasound technique can increase the movement of human sperm in the laboratory by up to 266%. Using microfluidic droplets to evaluate individual sperm cells, which had not been done before, they found that ultrasound exposure induced movement in immobile sperm and improved swimming speeds in mobile ones. The work is published today in the journal Science Advances.

A review of 25 studies conducted over nearly 50 years has found an association between insecticide exposure and lower sperm concentration. According to the authors, "insecticides are a public health concern for all men, who are exposed mainly through consumption of contaminated food and water". The results are published in the journal Environmental Health Perspectives.

Spermidine is a naturally occurring compound that has been linked to increased longevity in some organisms. New research shows that supplementation with this compound improves oocyte quality and fertility in older female mice. If its action and safety in humans is confirmed, the authors argue that it could serve as a therapeutic strategy to "improve the reproductive outcome of older women, either through natural pregnancy or assisted reproductive technologies". The results are published in the journal Nature Aging.
 

We compared semen analyses of 45 patients before and after mild covid-19 infection. We found a significant decrease in sperm volume, sperm concentration, total and progressive motility and vitality after infection, and that these effects may be long-term.

Two decades of research has found no differences in psychological well-being and the quality of family relationships between children born through assisted reproduction with third-party intervention (gamete donation or surrogacy) and those born naturally. The results, published in Developmental Psychology, suggest that it is better to talk to them early, at preschool age, about their biological origins.