Comparison between the quality and function of sperm after semen processing with two different methods

AIM: To compare the recovery rate of morphologically normal and chromatin condensed spermatozoa from native semen samples using the SpermPrep filtration columns and Percoll gradient centrifugation and to determine the influence of the two processing techniques on fertilization and pregnancy rates in an IVF-ET program. METHODS: Sixteen semen samples obtained from patient's husband were included in this study. Each was divided into two aliquots. The first aliquot was processed with SpermPrep filtration columns and the second, Percoll gradient centrifugation. Smears were made before and after semen processing with both methods for the evaluation of chromatin condensation (chromomycine CMA3) as well as morphology (strict criteria) of spermatozoa. One hundred and seventy oocytes were retrieved from the patients and the oocytes from each patient were subdivided into two sets: one set was inseminated using spermatozoa processed with SpermPrep and the other inseminated after semen processing with Percoll gradient centrifugation. RESULTS: The Percoll method yielded a significantly higher percentage of chromatin condensed (90.8 +/- 6.5% vs 82.3 +/- 8.8%, P = 0.017) and morphologically normal spermatozoa (12.9 +/- 7.4% vs 6.9 +/- 4.8%, P = 0.001) in comparison to SpermPrep. Whereas, sperm count recovery rate was significantly higher after the use of SpermPrep than after the Percoll gradient centrifugation. The fertilization rate was similar between the two methods. CONCLUSION: Semen processing with Percoll should be recommended for intracytoplasmic sperm injection as the natural selection is bypassed and the SpermPrep technique could be recommended for IVF and IUI programs as the sperm concentration plays a more significant role in these procedures.