Table 4.
Factors influencing the (correlating with) fertilization process and the onset of pregnancy
| Male/sperm factors | Female/oocyte factors |
|---|---|
| Sperm count | Maturity of oocyte |
| Motility | Maturity of spindle |
| Progressive motility | Maturity of zona pellucida |
| Morphology | Ability of the zona to induce acrosome reaction |
| Ability of spermatozoa to undergo capacitation | Intact cumulus‐oocyte complex |
| Ability to induce hyperactivation | Ability to modulate sperm functions |
| Ability to bind to the zona pellucida | DNA fragmentation |
| Ability to undergo acrosome reaction | Sufficient selection of functionally competent spermatozoa |
| Energy metabolism | Sufficient transport of functionally competent spermatozoa |
| Mitochondrial membrane potential | Sufficient supply of energy resources for spermatozoa |
| Membrane integrity | Ability to decondense the sperm head |
| Normal chromatin condensation | Ability to restore limited DNA damages |
| Ability to: bind to and fuse with the oolemma | Endometriosis |
| DNA fragmentation | NA |
| Influence of leukocytes | NA |
| Sufficient contribution of accessory sex glands | NA |
| Autoantibodies against spermatozoa | NA |
| Sperm maturity as tested by creatine kinase or HspA2 chaperone levels | NA |
| Sufficient elimination of the element zinc from the spermatozoa during epididymal maturation | NA |