Efficacy of the sperm survival test for the prediction of oocyte fertilization in culture

The present study was carried out to investigate the predictivevalue of the sperm survival test (SST) with respect to the fertilizationof oocytes in culture. In general, our laboratory uses a totalof 50 000–150 000 motile spermatozoa to inseminate eachoocyte. The remaining material is evaluated for motility beforeand after 24 h of incubation at 37°C in a 5% CO₂ atmosphere.A total of 250 oocytes from 50 cases (mean ± SD, 5.0± 2.4 oocytes per retrieval) were inseminated and thefinal rate of cleaved embryos obtained was 52.5%. The SST (%)was considered normal when the ratio (final density of progressingspermatozoa after 24 h x 100/initial density of progressingspermatozoa) was 50% or more. Any other result was consideredabnormal. Cases presenting one or more cleaved embryos (n =40) were separated from those in which no embryo formation occurred(n = 10) and the results were compared in terms of the respectivesperm survival rates over a period of 24 h: normal SST (oneor more cleaved embryos, 37; none, five), abnormal SST (oneor more cleaved embryos, three; none, five). The specificityof the SST was 0.92 and sensitivity 0.50, the predictive valueof the abnormal test was 0.62 and the predictive value of thenormal test 0.88. The efficacy of the test was estimated at0.71, which was better than the conventional parameters of spermanalysis. A receiver — operating characteristics curvefor SST confirmed that the test can be useful for the predictionof fertilizability of oocytes in the laboratory.