Correlation of sperm morphology and oxidative stress in infertile men

Excess reactive oxygen species (ROS) in the semen is believed to affect fertility in men. Morphologically abnormal sperms and their relation to seminal oxidative stress in infertile and subfertile men are not clear.

To correlate various sperm morphological defects with seminal oxidative stress in infertile and subfertile men.

The study included 25 primary, 21 secondary infertile men of idiopathic infertility and 15 fertile controls. Standard semen analysis was performed according to WHO (1999) guidelines. Sperm inter-morphological defects were evaluated in 100 sperms per sample by Giemsa staining. ROS in spermatozoa was measured by the chemiluminescence assay.

Significant difference in percent sperm amorphous head was found between secondary infertile group and control men. The study showed a significantly higher percent spermatozoa with residual cytoplasm between primary [11.61 (6.6, 3.9)], secondary [7.49 (0.8, 13)] and fertile controls [2.44 (0.8, 3.7)] similar to sperm count, percent sperm progressive motility, and ROS levels. A non significant but strong positive correlation (r=0.3479, p=0.0884) between percent cytoplasmic retained spermatozoa and ROS levels was observed in the primary infertile group. However, no correlation between other sperm morphological defects and oxidative stress was observed.

Sperm morphology was not found to be associated with oxidative stress in the present study. However, retained cytoplasmic residues in the sperm may be an important source of ROS in both primary and secondary infertile men. These immature spermatozoa are believed to be associated with impaired fertility.