Correlation between semen morphological analysis by motile sperm organelle morphology examination (MSOME) and sperm DNA damage

Abstract

OBJECTIVE: To evaluate the correlation between the motile sperm organelle morphology examination (MSOME) classification and sperm DNA damage. DESIGN: Prospective study. MATERIALS AND METHODS: Semen samples (358) were processed for MSOME and for DNA damage. -MSOME: 1ml of spermatozoa was place in a glass dish spermatozoa were analysed at 8400x magnification by inverted microscope equipped with Nomarski differential interference contrast optics. At least 200 motile spermatozoa per patient were evaluated and the percentage of normal spermatozoa, spermatozoa with low risk for chromatin damage (without regional disorder or vacuoles occupying more than 4% of the nuclear area) and vacuolated spermatozoa (vacuoles occupying >4% of the nuclear area) were determined. -DNA damage was measured by DNA fragmentation analysis using the terminal deoxyribonucleotidyl transferase mediated dUTP nick-end labelling (TUNEL) assay. The percentage of spermatozoa with fragmented DNA was determined in a fluorescence microscope. At least 200 spermatozoa in randomly selected areas on microscope slides were evaluated using a fluorescent microscope and the percentage of spermatozoa with fragmented DNA (TUNEL-positive cells) was determined. Percentages of spermatozoa forms observed by MSOME and TUNEL-positive spermatozoa were treated as a continuous variable. Correlations were performed using the Spearman rank correlation test. RESULTS: Regression analysis demonstrated that percentage of normal sperm forms and spermatozoa with low risk for chromatin damage by MSOME have significant negative correlation with percentage of DNA fragmentation (r=-0.25, P<0.0001 for both). However, there was a positive correlation between percentage of vacuolated spermatozoa and DNA fragmentation (r=0.27, P<0.00011). CONCLUSIONS: Sperm morphology by MSOME has a significant correlation with DNA damage. The present results support the routine use of MSOME for ICSI and as criteria for semen analysis with potential clinical repercussions.