The relationship between sperm concentration and fetilization in vitro of mouse eggs

Abstract

A 300 fold range of epididymal sperm concentrations (0.3-90 x 105/ml) has been tested to determine whether there is a relationship between sperm concentrations and level of fertilization achieved in vitro of mouse eggs. While very low concentrations (0.3-1.25 x 105/ml) resulted in relatively low fertilization (43-64%), those in the range of 2.5-90 x 105/ml gave fertilization rates of 80-94%. Consistently high results were obtained with sperm counts above 30 x 105/ml and there was no evidence of reduction in fertility with very high sperm concentrations. Likewise, no observable minimum was found, acceptable rates of fertilization were achieved with a mean sperm egg ratio of 417:1.