Simultaneous Assessment of Sperm Chromatin Condensation and Morphology Before and After Separation Procedures: Effect on the Clinical Outcome After In Vitro Fertilization

Abstract

Objective: To look for correlations between acridine orange (AO) staining and semen parameters before and after sperm separation procedures and to assess whether the AO test predicts fertilization or pregnancy outcomes after standard IVF and intracytoplasmic sperm injection. Design: Prospective study that simultaneously assesses sperm morphology and nuclear protein maturity on a cell-by-cell basis before and after preparative procedures. Setting: University teaching hospital. Patient(s): Men (n = 140) undergoing diagnostic semen analysis. Main Outcome Measure(s): Acridine orange fluorescence of sperm nuclei, semen parameters, IVF outcome. Result(s): In unprocessed samples, 90% of sperm with normal heads displayed green fluorescence (mature nuclear protein); significantly lower percentages of green fluorescence were observed in sperm with abnormal heads. The percentage of mature normal sperm in the specimen correlated with motility. Sperm maturity after swim-up or Percoll gradient was significantly improved for sperm with normal or abnormal heads. The percentage of mature normal sperm correlated with motility after either Percoll or swim-up. Neither the percentages of mature nuclei nor mature normal nuclei correlated with fertilization or pregnancy outcome. Conclusion(s): Nuclear protein maturation correlates with sperm motility and morphology. Because morphologically normal and motile sperm are more mature, separation procedures should generate a population of sperm with the highest fertilization capacity. Acridine orange staining, however, did not predict fertilization efficiency or pregnancy outcome in IVF cycles.