FAILURE OF MULTITUBE SPERM SWIM-UP FOR SEX PRESELECTION

Objective: To use double-label fluorescence in situ hybridization to e valuate a modified swim-up procedure that is purported to be effective for preconceptual sex selection. Design: Controlled, blinded study. S etting: University hospital laboratories. Patient(s): Donor males repo rting for routine semen analysis. Main Outcome Measure(s): Percentages of X- and Y-bearing spermatozoa in neat semen and in two swim-up frac tions, determined using double-label fluorescence in situ hybridizatio n. Result(s): No clinically significant change from a 1:1 ratio was fo und in the distribution of X- or Y-bearing spermatozoa after double-la bel fluorescence in situ hybridization following a modified swim-up pr ocedure and irrespective of the time (15, 30, 45, and 60 minutes) allo wed for swim-up. Conclusion(s): Using fluorescence in situ hybridizati on, a modified swim-up procedure was evaluated for its purported abili ty to skew the relative percentages of X- and Y-bearing spermatozoa. N o clinically significant change in the ratio of X- to Y-bearing sperma tozoa was detected independent of time. Therefore, clinical applicatio n of this procedure should be strongly discouraged. (C) 1997 by Americ an Society for Reproductive Medicine.