Chromosome analysis of human spermatozoa stored in vitro.

Two-hundred-sixty-five chromosome spreads from control human sperm samples capacitated in TEST-yolk buffer at 4 degrees C and 232 chromosome spreads from sperm samples incubated in vitro in Biggers-Whitten-Whittingham (BWW) for 24 h at room temperature prior to capacitation, were studied after fusion of sperm cells with zona-free hamster eggs. Sperm cells were provided by two volunteer donors. The results indicate an increase in chromosome structural abnormalities after in-vitro incubation of the spermatozoa from 1.8 to 7.7% in donor no. 1 and from 4.5 to 12.5% in donor no. 7. Overall, structural abnormalities increased 3.3-fold. The number of aneuploid spermatozoa and the sex ratio did not change significantly. The implications of the use of different media for storing spermatozoa are discussed.