Ultrasounds, the key to treating certain cases of male infertility

Ultrasounds, a non-invasive technique, could become a treatment for certain cases of male infertility. According to research published in the journal ‘Science Advances’, it can increase the movement of human sperm in the laboratory by up to 266%. Researchers at Monash University in Australia used droplet microfluidics to evaluate individual sperm cells, which had not been done before, and found that ultrasound exposure induced movement in immotile sperm and improved swimming speeds in mobile ones. The findings could help fertility doctors improve the results of assisted reproduction treatments. Related News standard No Many men associate a lack of sperm with sexual ability, which affects their mental health ABC Around 30 million men around the world are infertile Improve sperm motility (the ability of sperm to move independently) can considerably optimize the probability of successful fertilization without requiring more invasive and expensive techniques, such as intracytoplasmic sperm injection, performed during in vitro fertilization. «One of the main problems in cases of male infertility is asthenozoospermia, that is, the lack of mobility of sperm. Especially when the cause is not known. To solve this, assisted reproduction techniques such as ICSI are used, where only a mobile sperm is needed to introduce it into the oocyte,” Rocío Núñez, scientific director of the UR International Group and professor in the Master of Reproduction at the Complutense University and Society, tells SMC. Spanish Fertility. Drugs such as pentoxifylline have so far been developed to increase sperm motility, but their application has been limited due to potentially harmful side effects, such as damage to sperm DNA. A recent study has shown that ultrasound can improve sperm motility in humans and bulls by stimulating mitochondrial metabolism, but it has been difficult to evaluate the effectiveness of this technique at the single-cell level. It is known, adds Núñez to SMC, “that the lack of sperm motility is associated with an alteration in the mitochondria, which is like the “engine” of the sperm, which needs energy.” Improves more than 200% In this study, immotile and low-motility sperm were exposed to high-frequency ultrasound. The technique, which involved encapsulating individual sperm in microdroplets to image them, showed that ultrasound could improve sperm motility by up to 266%. And thanks to this, the sperm improved swimming speed and helped 34% of live, immotile sperm become mobile, which they associated with changes in mitochondrial function. “Our motility improvement results are promising for the application of this mechanotherapy method in assisted reproduction,” writes researcher Ali Vafaie. “Being able to alter motility can potentially shift therapy type selection and resulting outcomes toward the application of less invasive and more incremental options.” Núñez concludes that the true importance of this work lies in the possible application in cases of patients with completely immotile sperm or in testicular biopsy samples. «In these cases, techniques have been applied, such as those described, such as pentoxifylline, a substance that, when applied to sperm, causes their movement. However, its safety has not been proven and it is not useful in many cases. Therefore, being able to use a technique that is not harmful to sperm, without the need for staining or chemical treatment, offers tremendous potential to improve clinical outcomes through ICSI.” And, as Rita Vassena, co-founder and CEO of Fecundis and member of the Board of Directors of the Spanish Fertility Society, and previously scientific director of the Eugin Group, points out, this is “a novel study, since there is little evidence on the use of high-frequency ultrasound to stimulate sperm movement and had never been analyzed at the level of single cells, so the information provided is interesting and has the potential to be used in the clinic. “In fact, this work combines two very interesting techniques: one is high-frequency ultrasound and the other is a droplet microfluidic system that allows sperm to be analyzed one by one.” The true importance of this work lies in the possible application in cases of patients with totally immotile sperm Rocío Núñez Spanish Fertility Society But, she maintains, since the study remains in the semen sample analyzed and there are no clinical results after its use in patients, “it remains an open question whether the improvements observed in vitro in sperm motility will translate to improvements in the clinical outcomes of patients.” According to the WHO, there are 186 million people in the world who suffer from infertility, and half of the cases are male infertility. However, a small minority of patients are treated and overcome the disease. One of the most important reasons for this very low access to treatments is their costs and their low effectiveness. Given this emergency and a disease that is absolutely neglected globally, the results of this study indicate a possible strategy to adapt low-technological intensity treatments, such as classic in vitro insemination or intrauterine insemination, to more serious cases. “If the results were confirmed in a clinical setting, and their safety for the embryos to develop was proven, we could have a tool to make fertility treatments more accessible and successful,” adds Vassena.