In oocytes, mitochondrial DNA mutations do not increase with age in women, says a study published in Science Advances. The study detected mutations in different cells of 22 women between the ages of 20 and 42, and found that the mutations were more numerous in blood and saliva cells of older women, but not in their oocytes.
In 2015, the United Kingdom became the first country to pass legislation allowing the use of mitochondrial donation technology, pronuclear transfer. The technique is designed to limit, through in vitro fertilization, the transmission of mitochondrial DNA diseases in babies born to women who are at high risk, and for which there is no cure. Two studies published in the New England Journal of Medicine (NEJM) describe the results of the first treatments performed to date, from which eight babies have been born by mitochondrial donation, with reduced risk of disease.
A team in the United States has analysed how exposure to environmental chemicals in previous generations influences the onset of the first menstruation. The researchers used data from the California Child Health and Development Study (CHDS) and analysed blood samples taken from 250 pairs from the 1960s. The results, presented at the annual meeting of the Endocrine Society in San Francisco (USA), show that although the average age of first menstruation remained stable between grandmothers and their daughters, it decreased by one year between daughters and granddaughters. Certain chemicals present in the blood of the mother and father were linked to the onset of puberty in their descendants, with stronger effects in granddaughters, according to the study, and with greater weight of male exposure.
A research team from Murcia has found several types of microplastics in 69% of follicular fluid samples from 29 women and 55% of seminal fluid samples from 22 men, according to a presentation at the annual meeting of the European Society of Human Reproduction and Embryology (ESHRE), being held from 29 June to 2 July in Paris, France. The most frequent polymer in both types of samples was polytetrafluoroethylene (PTFE). The abstract of the research is published in the journal Human Reproduction.
Menstrual cycle tracking apps pose risks to users, according to a report published by the Minderoo Centre for Technology and Democracy at the University of Cambridge (United Kingdom). These apps collect intimate data about their users' physical and mental health and reproductive decisions, which can be exploited for commercial or legal purposes, the report warns.
Gonorrhoea is the second most common sexually transmitted disease in the world, with 80 million cases each year. There is no effective vaccine, and the bacteria responsible are becoming resistant to common antibiotics. Some studies have suggested that the meningococcal B vaccine, a unrelated bacterium, may offer partial protection against gonorrhoea. Now, an Italian team has identified 17 antibodies that could explain this cross-immunity, which, according to the authors, could be used to develop treatments and vaccines. The results are published in the journal Science Translational Medicine.
Research analysing 53 samples of human breast milk found that silica and metal nanoparticles were present in 42 of them. The study, published in PNAS, identified the mechanisms of nanoparticle infiltration from oral or respiratory exposure into blood vessels and subsequent accumulation in breast milk.
The role of midwives goes far beyond monitoring pregnancies and attending births. We explain why they are such a crucial part of the National Health System, what obstacles they face and what their main demands are.
A team of researchers has used embryonic stem cell engineering to create a bipaternal mouse - a mouse with two male parents - that lived to adulthood. Their results, published in the journal Cell Stem Cell, show how targeting a particular set of genes involved in reproduction enabled this breakthrough in unisexual reproduction in mammals.
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.