The use of a modified hypo-osmotic swelling test for the selection of viable ejaculated and testicular immotile spermatozoa in ICSI

A modified hypo-osmotic solution was used to select viable ejaculated and t esticular spermatozoa to perform intracytoplasmic sperm injection (ICSI) in 27 treatment cycles from patients with total absence of sperm motility. Th e treatment cycles consisted of 15 cycles in which ejaculated spermatozoa w ere used and 12 cycles in which testicular spermatozoa were used. The hypo- osmotic solution consisted of 50% culture medium and 50% deionized water an d was shown in previous in-vitro studies to be superior to the original sol ution used in the classical hypo-osmotic swelling test. Fertilization was a chieved in 37.3% of the oocytes injected, Embryos were replaced in 70.4% of the cycles with a mean of 2.0 embryos per cycle. There were no statistical ly significant differences between the ejaculated sperm group and the testi cular sperm group in the fertilization rate (42.7 versus 30.1%) or in the c leavage rate (92.7 versus 77.3%). Four pregnancies resulted, two in the eja culated sperm group and two in the testicular sperm group, a pregnancy rate of 14.8%. All pregnancies were singletons but one pregnancy in each group had an early miscarriage. There were no statistically significant differenc es between both groups in the pregnancy rates (13.3 versus 16.7%), in the i mplantation rates (5.3 versus 11.8%) or in the delivery/ongoing pregnancy r ates (6.7 versus 8.3%). It is concluded that the use of this solution to se lect viable but immotile spermatozoa for ICSI is a simple and practical met hod and is associated with acceptable fertilization and pregnancy rates.