EFFICACY OF THE SPERM SURVIVAL TEST FOR THE PREDICTION OF OOCYTE FERTILIZATION IN CULTURE

The present study was carried out to investigate the predictive value of the sperm survival test (SST) with respect to the fertilization of oocytes in culture. In general, our laboratory uses a total of 50 000 - 150 000 motile spermatozoa to inseminate each oocyte. The remaining material is evaluated for motility before and after 24 h of incubation at 37-degrees-C in a 5% CO2 atmosphere. A total of 250 oocytes from 5 0 cases (mean +/- SD, 5.0 +/- 2.4 oocytes per retrieval) were insemina ted and the final rate of cleaved embryos obtained was 52.5%. The SST (%) was considered normal when the ratio (final density of progressing spermatozoa after 24 h x 100/initial density of progressing spermatoz oa) was 50% or more. Any other result was considered abnormal. Cases p resenting one or more cleaved embryos (n = 40) were separated from tho se in which no embryo formation occurred (n = 10) and the results were compared in terms of the respective sperm survival rates over a perio d of 24 h: normal SST (one or more cleaved embryos, 37; none, five), a bnormal SST (one or more cleaved embryos, three; none, rive). The spec ificity of the SST was 0.92 and sensitivity 0.50, the predictive value of the abnormal test was 0.62 and the predictive value of the normal test 0.88. The efficacy of the test was estimated at 0.71, which was b etter than the conventional parameters of sperm analysis. A receiver - operating characteristics curve for SST confirmed that the test can b e useful for the prediction of fertilizability of oocytes in the labor atory.