Efficacy of zona-free hamster egg sperm penetration assay as a predictor of in vitro fertilization.

The efficacy of the zona-free hamster egg sperm penetration assay (SPA) as a predictor of in vitro fertilization (IVF) is studied. Indications for IVF were tubal factors in 35 couples and male factors in 24 couples. The diagnostic characteristics of SPA in reference to IVF for the whole group (n = 59) were reasonably reliable. Sensitivity was 74%, specificity was 84%, and diagnostic accuracy was 81%. However in patients with male factors, SPA was less reliable in terms of sensitivity (70%), specificity (57%), and diagnostic accuracy (63%), than in patients with tubal factors where the indicators were 80%, 97%, and 94%, respectively. Semen from patients with male infertility shared notable variations in terms of sperm density and motility which may account for the low SPA predictivity. SPA seems to be a useful screening test for prediction of IVF outcome. However other semen variables should be considered before interpretation, especially in male infertility where the diagnostic accuracy is low.