Sperm electron microscopy for the evaluation of in vitro fertilization failures.

When performing IVF, the clinician is frequently confronted with the failure of fertilization. When the standard parameters to evaluate the male factor are "within normal limits," the conclusion is often made that the lack of fertilization is most likely due to "poor egg quality." These two cases demonstrate the fallacy of this approach and support a more rigorous evaluation of the male factor. Ultrastructural analysis of sperm is underutilized and, as demonstrated by these two cases, can play an essential role in this evaluation process.