[Study of seminal fluid. Critical evaluation of various laboratory parameters]

The various humoral and morphological parameters on which examination of seminal fluid is based are considered. Two groups of causes that may modify normal fertility are pointed out: one concerns functional changes of the gonad and/or of the accessory glands, the other the ejaculatory phase and specifically the modalities for collecting the ejaculte. In this regard, stress is laid on how the first fraction of split ejaculate not only possesses biochemical characteristics different to those of the second fraction, but also presents a much higher sperm concentration and, hence, greater fertilizing capacity. It is therefore clear that separate examination of the two fractions may point to states of "latent" subfertility which global examination cannot spot.