Effects of the hypo-osmotic swelling test on the outcome of intracytoplasmic sperm injection for patients with only nonmotile spermatazoa available for injection: a prospective randomized trial

Objective: Hypo-osmotic swelling test (HOST) has been shown to be an effect ive method for the selection of live sperm. On-going pregnancies were obtai ned by using HOST-selected sperm. The aim of this study was to evaluate the effect of using HOST-selected "live" sperm Versus nonselected sperm on the outcome of intracytoplasmic sperm injection cycles when only nonmotile spe rm were available for injection. Design: Prospective randomized study. Setting: Governmental tertiary care hospital. Patient(s): Thirty ICSI cycles with no motile sperm were included in this s tudy. Intervention(s): For the HOST group, potentially Live spermatozoa detected by hypo-osmotic reaction of the tail were injected into oocytes. For the No -HOST group, the sperm were randomly injected into the oocytes without chec king the viability. Main Outcome Measure(s): The fertilization, cleavage, embryo quality, pregn ancy, and implantation rates were assessed for the two groups. Result(s): Among 30 cycles, 15 fall into each group. Fertilization, cleavag e rates, and the number of good quality embryos were similar between two gr oups. Conclusion(s): HOST-selected live spermatozoa can be safely used for intrac ytoplasmic sperm injection to establish pregnancies. There is a tendency fo r higher pregnancy and implantation rates to result, but it does not reach statistical significance. (C) 2001 by American Society for Reproductive Med icine.