Gametes and Assisted Conception The results obtained from a large study population reports that impairment of sperm characteristics was associated with an increase in the proportion of sperm with abnormal DNA. CASA estimation also indicate variation in patient and donor samples. It is clearly evident from this study that the method of sperm processing affects the quality of the resultant sperm population. Antioxidants can improve the processing outcome. Study of cryo preservation human semen with antioxidants/additives has shown to improve some of the post thaw characteristics. Moreover modifications in freezing or thawing techniques yielded favorable results Pronuclear (PN) analysis at fertilization stage has shown to predict the cleavage kinetics and embryo development patterns so as to select better quality embryos for transfer. Short co-incubation of spermatozoa with oocytes resulted in significantly higher grade-l embryos compared to the long incubation group. A modified method of freezing protocol indicate that this method may be applied to IVF programmes, which is less costly compared to slow-freezing protocols.