Recovery of motile sperm using the migration-sedimentation technique in an in-vitro fertilization-embryo transfer programme.

Sperm washing techniques, based on the swim-up principle used before inseminating the human oocyte in in-vitro fertilization and embryo transfer programmes (IVF-ET), usually require prior centrifugation which causes damage to the sperm cell. A technique is described for separating sperm at laboratory temperature based on sperm migration--sedimentation principles, using two concentric tubes and recovering 70-90% forward-moving cells. A group of 17 patients is presented who were managed with this method. The results were 85% fertilization rate, 4% polyspermia and six clinical pregnancies.