Sperm DNA Damage, ART Outcomes, and Laboratory Methods for Selecting DNA Intact Sperm for ICSI

Abstract

Sperm DNA fragmentation analysis involves a number of different molecular biology techniques able to determine specific harm on the DNA structure and has evolved from the initial and pioneering studies in the mid-1980s on animal models, where a strong link between sperm DNA damage and fertility was established, to later studies trying to associate these parameters with human male fertility status in addition to conventional semen analysis, also with the purpose to select the most DNA intact sperm within an ejaculate. The more techniques and research available, the more heterogeneity and confusion generated, while clinical decisions to take are confusing and sometimes have been wrongly taken on the basis of biased or incomplete studies together with a misinterpretation of the results obtained or the lack of accuracy of the employed techniques, adapted through the years not always supported by the best clinical evidences available. Nevertheless, the link with male infertility seems clear, the impact on assisted reproduction technique outcomes is generally accepted, and the availability of lab and surgical procedures to diminish the risk of using DNA damaged sperm is becoming more frequent and present on the routine clinical practice. The aim with this chapter is to provide a comprehensive review of the rationale and use of DNA fragmentation analysis in sperm and its clinical value, evaluating under the evidence-based medicine perspective the accuracy, robustness, and quantitative contribution of DNA intact sperm selection techniques to the patients’ success likelihood.