Can in-depth analysis of the mechanism of oocyte aging really improve the low success rate of IVF technology?

February 25, 2020 / BIOON / -- recently, a report was published in the international journal Cell reports In the previous research report, scientists from the University of New South Wales revealed the biological mechanism behind human infertility through research At the same time, their research on mice may help to understand the reproductive aging of the body, which may be expected to further research to improve the success rate of in vitro babies in human body Photo source: blacklistednews.com Nowadays, due to career and financial goals, more and more couples continue to postpone their childbearing age For many people, this may break the limit of the body's natural fertility After the age of 30, the body's fertility has begun to decline, while the body's ability to conceive at the age of 30-35 is half of that at the age of 19-25 For couples who are difficult to conceive, such as test tube babies, etc Reproductive medicine can provide some help At present, there are more and more people who need this technology in the world Although IVF is becoming more and more popular, its success rate is far from guaranteed In Australia and New Zealand, the success rate of women under 30 is only 29% per IVF cycle, and that of women 35-39 is only 16.5%, while that of women 40-44 is even lower, only 5.2%; the lower success rate of IVF means that women usually need repeated I VF cycle, and husband and wife must experience the psychological distress and tension brought by each failure cycle; most importantly, IVF will also bring certain burden to patients and medical system In Australia, the national insurance system has subsidized numerous cycles for many patients, regardless of their age, they still need to bear a large part of their own expenses, each cycle is about Thousands of dollars Egg cell: the bottleneck of childbearing is still the early abstinence of life at 35-40 years old So why are women at the peak of health in almost all other aspects, but it is difficult to get pregnant at such an early age? Surprisingly, the bottleneck of the body's reproductive age lies in the quality of the egg cells Although all other tissues in the body are made up of cells, which will be replaced by fresh cells on a regular basis, human beings are not able to produce new egg cells after birth, and women are born with all the oocytes in their lives When women are ready to be pregnant, they are The body's oocytes have been alive for decades, but also affected by age Although the ovaries eventually deplete the oocytes, the decline of oocyte quality is much earlier, and it is the most important factor affecting fertility Although the pregnancy rate of women who use their own eggs for IVF continues to decline, the proportion of women who choose to use the eggs donated by young women remains at a certain level; although many women in their forties are pregnant The cases are well known, but most importantly, they are not common They are usually caused by oocytes donated by young women Although using donor oocytes can overcome age-related reproductive barriers, they are accompanied by ethical issues related to obtaining donor oocytes, and will lead to offspring with different genetic compositions Aging oocytes will not only lead to Women have a low live birth rate and an increased risk of chromosomal disease in the embryo Bypassing the aging of an egg (a factor limiting a woman's fertility) is the use of "egg freezing" technology, which collects oocytes from a woman's body at an age and then freezes them for later use by the woman when she gives birth to the next generation In some Silicon Valley high-tech companies, such services have been provided as benefits to employees, and the marketing of the program has also been commercialized At present, the success of this method is far from guaranteed It's not only the aging of the egg cells, but also the aging of the male sperm The aging of the male sperm may be the main factor that affects the successful pregnancy of the female As the age increases, the risk of sperm defects will increase, which will inhibit the successful combination of sperm and egg cells However, there is a clear clinical solution to this problem, namely, intracytoplasmic sperm injection technology (ICSI), to study human beings A very fine needle is used to inject a single sperm cell directly into the egg cell This operation needs to be carried out under the laboratory microscope Therefore, although male infertility is still a very important problem, in most cases, the quality of female oocytes is still the most difficult to solve Photo source: Wikimedia can we improve the quality of oocytes? Although hormone therapy can increase the number of oocytes released by the female body, there is no effective way to improve the quality of oocytes, which is also a key goal in the field of reproductive aging research Recently, researchers have identified a new reason for the deterioration of oocyte quality as the body ages Researchers have found that the metabolism of oocytes and the stability of genome The level of the very important key molecules will decrease; when the special compounds are added to the drinking water of the experimental mice to restore the level of these molecules, the quality of the mouse egg cells can be restored, so that the mice can reproduce again Although this is only an animal study, relevant research results show that this method may be able to reverse the problem of female infertility, rather than simply slow down the decline of the body's reproductive age It should also be noted that in the absence of clinical evidence, researchers warn women who desperately want to be pregnant not to use supplements sold on the market; what makes researchers inconceivable is that due to patients' despair and lack of treatment methods, reproductive medicine generally uses measures that are not supported by strong clinical evidence to improve women's pregnancy resolution, such as drugs , supplements, expensive surgery, etc In the long run, the researchers say that this new strategy may improve the fertility success rate of couples facing fertility problems in the future, and reduce the impact of repeated invasive IVF cycles on the physical and mental health of patients Of course, the relevant research results are translated into expensive human clinical trials Maybe there is a long way to go At present, researchers don't know whether this strategy can play a role or be used safely in human body At the same time, researchers hope to jointly study the molecular biology of reproductive aging, so as to improve the treatment outcome of women and their infants Reference materials: [1] Michael J bertoldo, Dave R listijono, Wing Hong Jonathan Ho, et al NAD + completion measures female fertility during repetitive aging, cell reports (2020) doi: 10.1016/j.cellep.2020.01.058 [2] can low IVF success be reversed with new insights into egg cell aging? by Lindsay Wu， University of New South Wales