ASTHENOZOOSPERMIA AND THE HUMAN SPERM MID-PIECE

This study provides a quantitative comparison between surface and ultr astructural features of motile spermatozoa in asthenozoospermic and fe rtile men. The study group consisted of 10 individuals with persistent asthenozoospermia and the controls were 10 fertile donors to a sperm bank. Scanning electron microscopy and image analysis were used to obj ectively measure sperm mid-piece and tail dimensions. Sperm mid-piece length was significantly shorter (P < 0.01) in asthenozoospermic subje cts compared with the controls, with mid-piece width and tail length b eing comparable. Midpiece ultrastructure was then examined with the tr ansmission electron microscope and the number of mitochondrial gyres a nd their configuration recorded. At the ultrastructural level the asth enozoospermic subjects demonstrated significantly fewer mitochondrial gyres (P < 0.001) than their fertile counterparts. Energy for sperm mo vement is provided by mitochondria and a deficit in these organelles i n the sub-fertile cohort provides an explanation for poor sperm functi on in these subjects.