DNA strand breaks in human spermatozoa:: Correlation with fertilization in vitro in oligozoospermic men and in men with unexplained infertility

Background. The purpose of this study was to examine the correlation between DNA strand breaks in human spermatozoa and semen quality, fertilization rate and IVF outcome. Methods. A total of 50 men suffering from unexplained infertility and 50 men with oligozoospermia undergoing IVF treatment entered a prospective study. Sperm samples were assessed according to the WHO manual and for the presence of DNA strand breaks in spermatozoa. The study was blinded for the technician involved in assessment of DNA strand breaks. IVF was carried out according to a long down regulation protocol using GnRH, FSH and hCG. The ova were inseminated with 200,000 spermatozoa/ml. Embryos were transferred on day 2 after fertilization with a maximum of three embryos. Results. This study demonstrates a negative correlation between the proportion of spermatozoa having DNA strand breaks and the proportion of oocytes fertilized after IVF. Conclusion. The number of human spermatozoa with DNA strand breaks is a good predictor For fertilization rate in couples suffering from unexplained infertility and undergoing IVF treatment.