The contraceptive potential of fertilization: a physiological perspective
Bedford, J.M.
Human Reproduction 9(5): 842-858
1994
ISSN/ISBN: 0268-1161 PMID: 7929730 DOI: 10.1093/oxfordjournals.humrep.a138604Document Number: 288125
A specialist in reproduction and infertility reviews the physiology of fertilization and the contraceptive potential of fertilization. Suppression of the process by which spermatozoa can fertilize an ovum (capacitation) would be an attractive mode of contraception, but we do not know what factor(s) promote sperm capacitation in vivo. Other potential interventions are along the approach of spermatozoa to the ovum: sperm transport and the cumulus oophorus which houses the ovum. Sperm interaction with the egg is another potential intervention mechanism. This comprises several stages: sperm binding to the zona pellucida, induction of the acrosome reaction, sperm penetration of the zona pellucida, and zona penetrability and the block to polyspermy. A detailed discussion revolves around gamete fusion (i.e., sperm fusion with the zona pellucida). There is limited information about the accessibility of the fertilization site to drugs or other molecules and the principles that regulate their transfer. Fertilization research has focused almost entirely on mammals and not other vertebrates, which provides little biological perspective to the relative complexity of humans. The immunogenetics of each major sperm antigen needs to be established to avoid unacceptable variability.