Is there a specific abnormality of sperm morphology in men with varicoceles?

With the use of a case-control design, we have studied seminal cytology in 53 infertile men with large left varicoceles to determine whether they had a specific morphologic pattern. An equal number of infertile controls without varicoceles were matched for characteristics such as left testicular size, serum follicle-stimulating hormone levels, and sperm concentration to ensure similar degrees of testicular dysfunction. No significant difference in the morphologic patterns was observed, especially in the hallmarks of the "stress pattern": increased percentages of spermatozoa with tapering heads (1.8 +/- 2.6:1.9 +/- 4.0) and immature forms (8.1 +/- 5.4:6.4 +/- 2.9) in the varicocele and control groups, respectively. Assessment of morphologic characteristics was associated with wide errors (approximately 20% to 80%) among technicians working in the same laboratory. There does not appear to be a characteristic morphologic stress pattern in infertile men with large left varicoceles.