Zona-free hamster ovum penetration assay as a screening procedure for in vitro fertilization

Twenty couples with primary sterility due to mechanical factors entered our program of IVF. In addition to routine sperm evaluation, an SPA was performed in all cases. Whenever the SPA was pathologic, none of the human ova were fertilized in vitro, while 77% of the patients with a normal SPA had IVF of at least one human ovum. The good correlation between pathologic SPA and failure of IVF stresses the clinical value of this assay. The use of the SPA for patient selection for IVF is suggested.