Absence of glucose decreases human fertilization and sperm movement characteristics in vitro

The effect of glucose in a modified Ham's F10 medium (MM) without hypoxanthine, phosphate and transition metals on human fertilization and sperm survival in vitro was determined. Mature human oocytes from in-vitro fertilization (IVF) patients or Percoll-washed human spermatozoa were randomly allocated to one of the treatment groups: normal Ham's F10, MM, MM with 5 mM glucose (HGMM) and MM with 0.5 mM glucose (LGMM). Oocytes were inseminated in one of the four media for 12-20 h and checked for fertilization. Sperm were incubated likewise for 4 and 24 h, and sperm motility and sperm movement characteristics including average path velocity (VAP), curvilinear velocity (VCL), straight line velocity (VSL), amplitude of lateral head displacement (ALH), beat cross frequency (BCF), straightness (STR), and linearity (LIN) were determined using computer-assisted semen analysis. Fertilization rates were significantly lower in oocytes cultured in MM (23.8%) compared to LGMM (75.5%), HGMM (73.6%) or Ham's F10 (71.1%). Sperm characteristics after 4 h incubation in all four media were similar, except VAP, VSL, VCL and ALH were significantly lower in MM (no glucose) in comparison with the other three media. After 24 h VAP, VSL, VCL, ALH, LIN and percentage rapid spermatozoa were significantly higher in spermatozoa incubated in HGMM or Ham's F10 compared with MM or LGMM. Also after 24 h, the percentage of spermatozoa which were highly motile was greater in HGMM than in Ham's F10. Absence of glucose significantly lowered fertilization rates and sperm movement characteristics in vitro.