Objective: To evaluate the influence of DNA fragmentation, DNA methylation, and protamine deficiency as indicators of chromatin status on assisted reproductive technology outcome, and also to assess the relation between these parameters.
Design: Prospective study.
Setting: Royan Institute and Isfahan Fertility and Infertility Center.
Patient(s): Semen samples from 92 infertile couples undergoing intracytoplasmic sperm injection (ICSI) and IVF were assessed during this study.
Intervention(s): Semen analysis was carried out according to World Health Organization criteria. Protamine deficiency, DNA methylation, and DNA fragmentation were assessed by chromomycin A3 (CMA3), immunostaining, and sperm chromatin dispersion, respectively.
Main outcome measure(s): Chromomycin A3 positivity, DNA methylation, DNA fragmentation and assisted reproductive technology outcome.
Result(s): Chromomycin A3 positivity shows a significant correlation with DNA fragmentation and fertilization rate. Furthermore, unlike in IVF patients, DNA fragmentation showed a significant negative correlation with fertilization rate in ICSI. A significant negative correlation was observed between DNA methylation and DNA fragmentation. In addition, no correlation was found between fertilization rate and DNA methylation in both IVF and ICSI patients.
Conclusion(s): The results reveal that in ICSI procedure DNA fragmentation, and CMA3 positivity affect the fertilization rate, whereas none of these parameters affect postfertilization development. Furthermore, both CMA3 positivity and DNA methylation affect DNA fragmentation, independently of each other. Thus, it can be concluded that these parameters may play an early role in initiation of development.