If hormone levels affect sperm motility during capacitation, then the serum added to samples prepared for artificial insemination could affect sperm fertilizability. We investigated various sperm functional movement characteristics (percent motile, progressive velocity, linearity, beat cross frequency, lateral head displacement, longevity, and hyperactivation) in specimens incubated with women's sera, as well as exogenous hormone preparations of estradiol (E2) and progesterone (P). Early follicular phase serum (low E2 and low P) maintained motility and longevity. Sperm in E2-treated medium exhibited higher progressive velocity, linear motility, and longevity. In contrast, the percent motility decreased as sperm exhibited hyperactivated motility with P.