Advanced label-free optical methods for spermatozoa quality assessment and selection

Current in vitro fertilization (IVF) techniques require a severe selection of sperm, generally based on concentration, morphology, motility and DNA integrity. Since routinely separation methods may damage the viability of the sperm cell, there is a growing interest in providing a method for non-invasively analysing spermatozoa taking into account all those parameters. This chapter will first review the state-of-the-art of label-free sperm cell imaging for IVF, highlighting the limitations of the used techniques. Then, our innovative approach combining Raman spectroscopy and digital holography will be described and its advantages detailed. These include the ability to perform a simultaneous and correlative morphological and biochemical analysis of sperm cells, without labelling, in a fast and reliable way. Finally, the difficulty in reaching clinical use will be discussed, as well as the possible solutions offered by new technological improvements.