Table 1 Numerical index for the evaluation of sperm motility

Spermatozoa motility index (SAI)	Score*	Motility characteristics
I	3	Sperm display forward movement rapidly
II	2	Sperm display forward movement slowly
III	1	Sperm display vibrating movement moderately
IV	0	Immobile sperm

^* SAI: (Score × % motile sperm)/100 (After Strüssmann et al., 1994).