Oligoasthenoteratozoospermic patients with high untreatable sperm DNA fragmentation and prior ICSI failure using ejaculated sperm have signs of partial epididymal obstruction.

Abstract

Background: Previous studies have suggested using testicular sperm for ICSI in patients with oligoasthenoteratozoospermia (OAT) and high, untreatable sperm DNA fragmentation (SDF) with prior ICSI failures using ejaculated sperm, to improve their chances of successful ICSI outcome.

Objectives: To assess whether such patients have signs of partial epididymal obstruction.

Materials and methods: We retrospectively evaluated 72 infertile men with OAT (sperm count < 10 million/mL, progressive motility < 30%, morphology < 4%) and high (> 30%) SDF who underwent ICSI with testicular sperm following at least two prior ICSI failures with ejaculated sperm; they were divided in two subgroups based on testis histology results indicating either normal or impaired spermatogenesis. 186 patients with nonobstructive azoospermia (NOA) and 45 patients with obstructive azoospermia (OA) served as control subjects for hormonal and histological parameters.

Results: 34 out of 72 (47.2%) OAT patients had normal spermatogenesis, with hormonal and histopathological characteristics comparable to those of men with OA, while 38 patients (52.7%) showed spermatogenic dysfunction but of lesser severity compared to patients with NOA. At scrotal surgical inspection, all OAT patients showed signs of partial epididymal obstruction. ICSI clinical pregnancy and live birth rate using testicular sperm was 45.8% and 36.11% respectively, and did not differ among patients with normal or impaired spermatogenesis (50% vs. 42%, p = 0.64, and 41.1% vs. 31.5%, p = 0.47, respectively).

Discussion: We hypothesize that partial epididymal obstruction may affect sperm maturation, particularly in relation to the noncoding RNA payload required for fertilization and early embryo development, which is acquired during epididymal transit. Nucleases activation in the cauda epididymis and vas deferens may degrade sperm DNA to prevent the involvement of functionally altered sperm in oocyte fertilization.

Conclusion: High untreatable SDF, together with prior ICSI failure using ejaculated sperm, could be interpreted as sign of partial epididymal obstruction in patients with OAT.