Human sperm--egg interactions and their disorders: implications in the management of infertility

The present era of infertility management is characterized byan increasing interest in defects of sperm-egg interactions.When the spermatozoon meets the egg, it must first react withthe enveloping coat which controls sperm access to the cellsurface of the oocyte. Adequate sperm motility is a major conditionfor penetration through the egg investments. The ability ofspermatozoa to respond to physiological stimuli by a timelyacrosome reaction is another necessary prerequisite for thisevent, as well as for sperm fusion with the oocyte. The clinicalsignificance of current laboratory tests evaluating differentaspects of gamete function is discussed and a practical guideis given for their indication and interpretation and for theuse of their results in choosing rational therapy.