SPERM DECONDENSATION AND SEMEN PARAMETERS - UTILIZATION OF A SIMPLE STAINING TECHNIQUE FOR THE EVALUATION OF HUMAN SPERM DECONDENSATION

The ability of spermatozoa to fertilize an oocyte depends on a sequenc e of events ending ultimately in the decondensation of the sperm chrom atin on penetration of the oocyte. Knowledge of what percentage of spe rm decondenses is useful, especially in patients where other functiona l tests and sperm quality fail to explain the reported poor in vitro f ertilization (IVF) rates. The objective of this study was (1) to compa re sperm decondensation induced by either SDS/EDTA or heparin with sem en parameters (volume, concentration, motility and morphology), and (2 ) to evaluate the use of a simplified staining technique (Diff Quik(R) DQ) in comparison with the standard phase contrast method (Rose Ben gal-RB). Randomly selected semen samples from 31 men attending an as sisted reproductive programme were analysed for basic semen parameters and decondensation with SDS/EDTA and heparin. Two staining methods fo r the evaluation of decondensation were compared (phase contrast micro scopy after Rose Bengal RB staining and light microscopy after Diff Quik(R) (DQ) staining). Moderate and grossly swollen sperm heads were recorded. Semen samples included both fertile and unfertile semen para meters. Sperm decondensation results showed poor to moderate correlati ons with semen parameters. The SDS/EDTA (DQ) (moderate forms) showed a significant negative correlation (r=-0.46) with seminal volume and an d a significant positive correlation (r=0.41) with normal sperm morpho logy. The heparin (DQ) (moderate forms) decondensation showed a signif icant positive correlation with motility (r=0.61) and sperm concentrat ion (r=0.43). The DQ method was preferred over the RB method due to it optical and storage advantage. Sperm decondensation by SDS/EDTA and h eparin have limited use in the IVF laboratory as they correlate poorly with semen parameters. Future studies should investigate the use of a n ooplasmic factor similar to nucleoplasmin in Xenopus laevis egg.