Modern techniques of sperm preparation--do they influence the sex of offspring?

Four different semen preparation methods--migration-Sedimentation technique, Sperm Select, Percoll gradient centrifugation and swim-up technique--have been tested and compared in regard to progressive motility, viability and morphology. The data obtained clearly demonstrate significant enhancement of all parameters using the techniques mentioned above. The study also demonstrated significant differences in Y chromatin-positive spermatozoa before and after semen preparation. The rate of F-body-positive spermatozoa was significantly increased by all four methods.