Enhancing male fertility diagnostics with seminal plasma Raman spectroscopy

Seminal plasma (SP) constitutes approximately 95% of the ejaculate volume and plays a crucial role in modulating sperm function. The analysis of SP through Raman spectroscopy provides valuable insights into the molecular composition of its constituents, offering the potential for enhanced diagnostic approaches in male fertility assessment. In this pilot study, we obtained in vitro Raman spectra from 70 dried SP samples in the range from 400 to 1900 $\mathrm{cm}$^-1 using a laser excitation wavelength of 532 nm. We employed Multivariate Curve Resolution (MCR) analysis and decomposed the Raman spectra into three key components: tyrosine, spermine phosphate hexahydrate, and a protein-rich component. We identified notable differences in the Raman spectra of normal and abnormal samples, particularly in peak intensities at 625, 1440, and 1008 $\mathrm{cm}$^-1 providing reliable criteria for differentiation with a specificity of 79% and sensitivity of 95%. The high classification rates achieved in this study not only confirm the efficacy of Raman spectroscopy as a diagnostic tool but also suggest that it could be pivotal in uncovering molecular-level abnormalities that standard semen analysis may overlook. Based on our literature review, this is the first study that highlights the biochemical distinctions between normal and abnormal SP samples in accordance with the criteria established by the World Health Organization (WHO), which includes factors such as sperm count, progressive motility, and normal morphology. Our findings contribute to the growing body of knowledge surrounding male infertility diagnostics and emphasize the necessity for innovative approaches in understanding and addressing reproductive health challenges.