The viability of spermatozoa moving in straight lines should be greater than 32% to be normal. Sperm viability is categorized into four grades, of which grade A indicates that the spermatozoa are well active and move forward in a fast, lively straight line. grade B indicates that the spermatozoa can move in a straight line but move slowly. grade C indicates that the spermatozoa are poorly motile, spinning or rotating in place. grade D indicates that the spermatozoa are inactive. straight-line motility is generally categorized into grade A and B spermatozoa, and the total number of spermatozoa in the two grades should be greater than 32% of the total number of spermatozoa. Whether or not you can get pregnant is not assessed by this one indicator alone, but should be judged comprehensively, such as the amount of sperm, sperm liquefaction time, sperm PH, and the percentage of sperm moving forward.