Fertilising capacity of human sperms: A simple predictive assay

Abstract

Male subfertility is a growing reason for assisted reproduction. A limiting factor in male subfertility is asthenospcrmia. Motility is a cardinal indication of sperm vitality. Thus prognostic assays are aimed at quantitative determination of progression to assess the fertilising potential. However, a method permitting reliable prognosis of the fertilising capacity has yet to be developed. The assay presented here is the outcome of empirical data based on 590 IVF (<i>in vitro </i>fertilisation) trials. It is essentially a further exploitation of the Swim Up procedure, the selected sperms being maintained in culture under identical conditions employed in IVF.Semi-quantitative daily recordings of linear progression until complete extinction provided an index on vitality which is directly related to the fertilising potential. The findings indicated that a threshold of 50% linear motility after 24 hr culture was required to initiate fertilisation. The fertilising potential was guaranteed when at least 60% linear motility was observed at 24 hr, making the assay a predictive one. Its simplicity is an attractive feature.