New era in sperm selection for ICSI.

Spermatozoa contribute to approximately half of the genome of future progeny, and therefore, have a profound impact on embryo development post-fertilization. Sperm selection based on viability and normal morphology does not eliminate the chance for DNA damaged spermatozoa to be inseminated and may account for a considerable percentage of failed embryo development post-ICSI (Intra cytoplasmic sperm injection). Therefore, sperm selection based on functional sperm characteristics to preclude insemination of DNA damaged spermatozoa have paved the way for successful ICSI outcomes. In regard to this, different laboratories have introduced novel procedures to replace traditional or orthodox sperm selection methods. This review attempts to provide information on the scientific bases of each procedure, and pinpoint their advantages and disadvantages. In addition to data from our research, a systematic search on the literature, publications and presentations was carried out using such databases as PubMed and ISI-Web.