[Effect of late motility on the fertilization of ova in the IVF program].

In the course of the IVF programme at our department we made the observation that even with primarily normal sperm counts late motility often varies widely. The impression that late sperm motility might be related to successful fertilisation caused us to study the influence of late sperm motility on fertilisation rates in a series of 80 patients. Sperm was capacitated with B2 medium (Menezo INRA). Even in the presence of an originally normal sperm count, reduced late motility was associated with lower fertilisation and embryo transfer rates. It seems that late sperm motility will have to be considered as an important parameter in evaluating the prognosis for successful IVF and ET.