This is an examination of the post-orgasmic portion of urine for the presence of spermatozoa in order to diagnose retrograde ejaculation. A portion of urine is collected immediately after a successful masturbation with no ejaculate (aspergillosis) or less than 1.0 ml of ejaculate (oligospermia). Retrograde ejaculation is a complete, sometimes partial absence of antegrade ejaculation as a result of the backflow of sperm into the bladder through its neck.