Abstract
To examine the relationship between sperm strict morphology and sperm chromatin integrity.
Prospective study.
Infertility clinic.
Eighty-seven consecutive semen samples from non-azoospermic men presenting for infertility evaluation and 6 samples from fertile donors.
Assessment of standard semen parameters and sperm chromatin structure assay (SCSA) parameters (%DFI [DNA fragmentation index] and %HDS [high DNA stainability]). Evaluation of %HDS and %DFI after treatment with dithiothreitol (a thiol-reducing agent used to decondense sperm nuclei) was also undertaken.
Relationship between sperm strict morphology defects and SCSA parameters (%DFI and %HDS).
We observed significant relationships between the percentage of normal sperm forms and both %HDS (
r = −0.40) and sperm motility (
r = 0.32). We also found significant relationships between sperm head defects and both %HDS (
r = 0.40) and sperm concentration (
r = −0.39). Sperm tail, midpiece, and neck defects were not significantly related to the SCSA parameters. Treatment of spermatozoa with dithiothreitol (to induce decondensation) resulted in a substantial increase in %HDS but no measurable change in %DFI.
The observed relationship between sperm head defects and %HDS suggests that sperm head abnormalities may, in part, be due to incomplete sperm chromatin condensation.