Protamines and DNA integrity as a biomarkers of sperm quality and assisted conception outcome

Present research aim was to identify functional tests in semen associated with DNA damage and chromatin maturity (protamination) which predict the outcome in assisted reproduction. Couples were grouped according to male partner semen parameters, into normozoospermia (NZs), severe male factor (SMF) and mild male factor (MMF). DNA fragmentation index (DFI) in spermatozoa was analysed by sperms chromatin dispersion (SCD), sperm chromatin structure assay (SCSA) and acridine orange testing (AOT). Chromomycin A3 (CMA3) and toluidine blue (TB) staining to measure sperm chromatin maturity (CM). DFI and chromatin decondensation were significantly lower in N compared to male factor categories (MMF and SMF). Aneuploidy embryos were significantly higher in couples with male factor infertility (MMF and SMF). A positive correlation was observed between fertilization rate (FR) and live birth rate (LBR) with sperm concentration, motility, vitality, normal sperm morphology and negative correlation between sperm DFI and sperm CM. No correlation was observed between embryo aneuploidy and sperm DFI or CM. Lower percentage of spermatozoa chromatin integrity are associated with low fertilization and live birth rate. Male factor infertility, due to impaired semen parameters and chromatin defects could be regarded in future as an indication of IVF/ICSI, and predictor of assisted reproductive techniques outcome.

Utility of antioxidants during assisted reproductive techniques: an evidence based review

Assisted reproductive technology (ART) is a common treatment of choice for many couples facing infertility issues, be it due to male or female factor, or idiopathic. Employment of ART techniques, however, come with its own challenges as the in vitro environment is not nearly as ideal as the in vivo environment, where reactive oxygen species (ROS) build-up leading to oxidative stress is kept in check by the endogenous antioxidants system. While physiological amounts of ROS are necessary for normal reproductive function in vivo, in vitro manipulation of gametes and embryos exposes these cells to excessive ROS production either by endogenous or exogenous environmental factors. In this review, we discuss the sources of ROS in an in vitro clinical setting and the influence of oxidative stress on gamete/embryo quality and the outcome of IVF/ICSI. Sources of ROS and different strategies of overcoming the excessive generation of ROS in vitro are also highlighted. Endogenously, the gametes and the developing embryo become sources of ROS. Multiple exogenous factors act as potential sources of ROS, including exposure to visible light, composition of culture media, pH and temperature, oxygen concentration, centrifugation during spermatozoa preparation, ART technique involving handling of gamete/embryo and cryopreservation technique (freeze/thawing process). Finally, the use of antioxidants as agents to minimize ROS generation in the in vitro environment and as oral therapy is highlighted. Both enzymatic and non-enzymatic antioxidants are discussed and the outcome of studies using these antioxidants as oral therapy in the male or female or its use in vitro in media is presented. While results of studies using certain antioxidant agents are promising, the current body of evidence as a whole suggests the need for further well-designed and larger scale randomized controlled studies, as well as research to minimize oxidative stress conditions in the clinical ART setting.