LISBON, Nov. 16 (Xinhua) -- Researchers from the University of Coimbra (UC) have published a study identifying causes of male infertility that were previously classified as "unexplained."
The scientists were able to clarify molecular and metabolic details linked to this type of infertility, which are not routinely evaluated and can be crucial for better diagnosis and effective treatment.
"Infertility is a disease with a significant impact on the lives, health and well-being of affected couples, who often suffer from psychosocial and financial problems," Sandra Amaral, a researcher at the Center for Neuroscience and Cell Biology at UC (CNC-UC), said.
In Portugal, infertility is estimated to affect around 300,000 couples, with the male factor contributing to about 50 percent of the cases.
However, Amaral said that the cause of male infertility cannot be identified in approximately 30 percent of cases - this is the so-called "unexplained male infertility."
The scientific article "New Insights on Sperm Function in Male Infertility of Unknown Origin: A Multimodal Approach" was published in the journal Biomolecules.
Portuguese scientists investigated more than 1,400 patients, analyzing sperm from healthy individuals without fertility problems and also from men diagnosed with infertility of unknown origin.
The scientists identified certain functional aspects of the male gamete that are affected, including the integrity of its DNA.
The capacitation process (which gives the gamete the ability to fertilize) and mitochondrial function were also highlighted.
Additionally, the research team identified six differentially expressed proteins in individuals diagnosed with infertility. The researchers believe that all these aspects are affecting the fertilization potential of sperm.
"These new functional aspects presented in this study provide new information that may, in the future, identify the causative factors of infertility in these men, opening the door to improvement in diagnostic methods and future treatments," Amaral said. ■