TESTS OF SPERM FERTILIZING ABILITY (HUMST ER, ULTRASTRUCTURE) ARE THEY USEFUL

Tests of sperm function are often considered to be able to predict the in vivo or in vitro fertility of a given patient although they only a ssess part of the process of sperm fertilizing ability. It appears fro m the literature, that the sperm penetration assay (SPA) which investi gates the sperm fusiogenic and nuclear functions cannot accurately pre dict the in vivo fertility and there is still much debate on the relia bility of its correlation with in vitro fertilization (IVF) principall y in cases of severe sperm deficiency. With the development of new tec hniques of assisted fertilization, by-passing the zona pellucida, a te st of sperm fusion, hetero or homospecific as well, could be interesti ng. Considering sperm ultrastructure and beyond some specific morpholo gical alterations of the whole sperm population that can be responsibl e for the infertility, such studies were not able, as yet, to reveal s ignificative differences between semens fertile in vitro or not.