A new approach to evaluate aging effects on human oocytes: Fourier transform infrared imaging spectroscopy study

ObjectiveTo characterize from a vibrational point of view the alterations caused by aging on human oocytes.DesignReproductive biology.SettingPrivate assisted reproductive technology clinic, synchrotron beam line, and university infrared laboratory.Patient(s)Twenty women of different ages (30 ± 2 and 39 ± 2 years) selected on the basis of detailed inclusion criteria and submitted to controlled ovarian stimulation according to a specific protocol.Intervention(s)Collection of 68 supernumerary oocytes that were not used during the IVF cycle from the above cited consenting patients.Main Outcome Measure(s)Focal Plane Array Fourier transform infrared (FTIR) analysis of human oocytes.Result(s)Specific spectral differences were highlighted in the two experimental groups of oocytes. In particular, in oocytes of 39-year-old women, the occurrence of peroxidative processes and a decrease in the amount of carbohydrates were observed, together with alterations in the phospholipid membrane, proteic pattern, and nucleic acids content.Conclusion(s)For the first time, FTIR spectroscopy was applied to human oocytes, leading to strong evidence of damage from aging in the gametes of mature women, which could be related to a decline in reproductive function. All the information obtained may be considered useful to improve the scientific knowledge on human reproduction and to exploit new strategies for detecting oocyte aging.