Evaluation of sperm head shape at high magnification revealed correlation of sperm DNA fragmentation with aberrant head ellipticity and angularity

Abstract

To test for an association between DNA fragmentation and head shape at high magnification in fresh motile spermatozoa. Observational study. Academic tertiary care center. A total of 60 men in our assisted reproductive program. Quantifying sperm head shape using elliptic Fourier analysis, and detecting DNA fragmentation by use of a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Correlation between percentage of spermatozoa with abnormal head shape and percentage of DNA fragmentation. Elliptic Fourier analysis decomposed sperm head shapes into four quantitative parameters: ellipticity, anteroposterior (AP) symmetry, lateral symmetry, and angularity. The DNA fragmentation was statistically significantly correlated with abnormal angularity, and moderately with abnormal ellipticity but not with abnormal AP symmetry or lateral symmetry. Forward stepwise multiple logistic regression analysis revealed a statistically significantly higher percentage of DNA fragmentation in spermatozoa with abnormal ellipticity and abnormal angularity than in spermatozoa with normal-shaped head (6.1% and 5.4% vs. 2.8%). Spermatozoa with large nuclear vacuoles also correlated with sperm DNA fragmentation, and had a statistically significantly higher percentage of DNA fragmentation (4.7%). Among the morphologic features of the sperm head, abnormal ellipticity, angularity, and large nuclear vacuoles are associated with DNA fragmentation.