PREGNANCY FOLLOWING INTRACYTOPLASMIC SPERM INJECTION OF IMMOTILE SPERMATOZOA SELECTED BY THE HYPOOSMOTIC SWELLING-TEST - A CASE-REPORT

The success of intracytoplasmic sperm injection (ICSI) is poor when on ly immotile spermatozoa can be retrieved. In a couple with complete ma le asthenozoospermia the possible use of the hypo-osmotic swelling tes t to select spermatozoa for microinjection was examined. Following inc ubation in hypo-osmotic medium (Hypo 10, IVF Science, Goteborg, Sweden ), 26% of immotile spermatozoa showed signs of sperm swelling (HOS-pos itive). After injection of HOS-positive spermatozoa, 5 out of 12 oocyt es fertilized (41%) and after transfer of three embryos a healthy sing leton pregnancy was achieved. In a previous ICSI cycle of this couple without preselection of spermatozoa by the HOS test, only 1 out of 10 oocytes fertilized. It is concluded that selection of spermatozoa by h ypo-osmotic swelling-test prior to sperm microinjection seems to be a valuable tool to increase the fertilization rate in cases with complet e asthenozoospermia.