Assisted reproductive technology outcomes in obese and diabetic men: lighting the darkness

The prevalence of obesity and diabetes, two of the most prevalent metabolic disorders (MetDs) in the world, has been rising exponentially over the last two decades. In addition to other comorbidities, MetDs have a detrimental impact on reproductive features, leading to a boost of the use of assisted reproductive technologies (ARTs) to overcome fertility problems. Although ARTs help to improve MetD male reproductive outcomes, data show that the results are less successful compared with those of men without MetD. Currently, intracytoplasmic sperm injection is the election procedure to bypass infertility in men with MetD. Nevertheless, embryos obtained by intracytoplasmic sperm injection using spermatozoa of men with MetD have a lower probability to end in a live birth. This embryo development shutdown has been related to a higher rate of spermatozoa with fragmented DNA and with modifications on pathways that do not allow embryos to go further in the development process. This special detrimental feature of sperm from men with MetD indicates that advanced sperm selection techniques should be used in these patients to avoid sperm with fragmented DNA. Fortunately, sperm selection procedures are under constant development and eventually will allow physicians to select spermatozoa with higher quality and low DNA fragmentation to be used in further ART, increasing the outcome of those procedures. Future research should be performed to enlighten alterations in embryos derived from spermatozoa of men with MetD.