[Diagnosis of male infertility: a need of functional and chromatin evaluation]

To evaluate the incidence of functional and chromatin alterations on spermatozoids in patients grouped according to normality of standard semen parameters based on the 5th edition of the World Health Organization (WHO) guidelines. To identify and correlate the most frequently altered characteristics in the normal standard semen parameters sub-population.

A prospective study was performed. It evaluated standard semen parameters (volume, sperm concentration, motility and morphology, round cells, peroxidase-positive cells) according to WHO guidelines, as well as functional tests (24 hours survival, hypoosmotic swelling test, modified stress test), and additional assays (aniline blue, nitroblue-tetrazolium, TUNEL) in 110 semen samples from patients and 6 from fertile donors (control). Based on standard semen parameters values, patients were divided into two groups (A: all standard parameters normal; B: one altered standard parameter at least).

At least one of the variables analyzed was altered in 96.61% of the samples. Groups A and B showed statistically significant differences in all the complementary tests. At least one of the complementary tests were altered in 93.68% of the samples in group A, and the most frequently affected variable was sperm DNA fragmentation (16.95%).

Performing a more in-depth seminal study within the routine functional and chromatin assays provides a more precise diagnosis of male infertility. The WHO standards should be considered as a primary approach.