The aim of this study was to determine the predictive value of sperm penetr
ation into the perivitelline space of human cadaveric oocytes on in vitro f
ertilization outcome. Forty-two patients with tubal infertility undergoing
ovarian stimulation with gonadotropin for in vitro fertilization and embryo
transfer participated in the study. The number of spermatozoa bound to the
human zona pellucida, the percentage of cadaveric oocytes with one or more
spermatozoa in the perivitelline space, and the in vitro fertilization out
come were evaluated. Spermatozoa from 37 of 42 patients were able to penetr
ate the perivitelline space of cadaveric oocytes as well as to fertilize hu
man oocytes in vitro. In three individuals, no penetration of the perivitel
line space of cadaveric oocytes was observed and no in vitro fertilization
was detected. Only two patients were able to fertilize the couple's oocytes
without penetration of the cadaveric oocytes. Based on these results the s
pecificity and the sensitivity of the assay to predict in vitro fertilizati
on was 100% and 94.1%,, respectively. Accordingly, these results suggest th
at sperm-zona penetration is a useful bioassay to predict male fertility po
tential in IVF outcome.