Use of high-magnification microscopy for the assessment of sperm recovered after two different sperm processing methods.

Objective: To compare the quality of sperm samples obtained after density-gradient centrifugation and swim-up by performing a nuclear structural analysis with high magnification microscopy at ×8,000.

Methods: Prospective and randomized split-sample study. Methods: Reproductive Medicine Center. Methods: Sperm samples from 53 male-partners of couples undergoing infertility treatment. Methods: Samples were analyzed by high magnification microscopy before and after preparation and classified according the level of nuclear vacuolization. Methods: Recovery rate, motility rate and percentage of sperm scoring each of 4 grades of vacuolization in fresh and processed sample.

Results: Both sperm processing methods, swim-up and density gradient centrifugation, allow the selection of sperm with lower nuclear vacuolization and presumably lower DNA fragmentation than the whole ejaculate.

Conclusions: Swim-up produces samples with less vacuolization, but the recovery rate is also lower. The choice of processing technique would then depend on whether intrauterine insemination, IVF or ICSI/IMSI is to be performed. A prospective randomized study scoring fertility rates would be necessary to directly access the influence of these methods on the fertility outcome.