Human Chorionic Gonadotropin
Most of the research into immunity that inhibits gamete outcome has focused on human chorionic gonadotropin (hCG). hCG is not necessary for fertilization, but is secreted by embryos shortly thereafter. Therefore immunity against hCG does not prevent fertilization. However, it was found that that anti-hCG antibodies prevent marmoset embryos from implanting in the endometrium of their mother's uterus.
The main function of hCG is to sustain the ovarian corpus luteum during pregnancy past the time it would normally decay as part of the regular menstrual cycle. For the first 7–9 weeks in humans, the corpus luteum secretes the progesterone necessary to maintain the viability of the endometrium for pregnancy. Therefore immunity against hCG during this time frame would function as an abortifacient, as confirmed by experiments in baboons. In the scientific literature the more inclusive term "birth control vaccine" rather than "contraceptive vaccine" is used to refer to hCG vaccines.
Read more about this topic: Immunocontraception, Gamete Outcome
Famous quotes containing the word human:
“To me the sole hope of human salvation lies in teaching Man to regard himself as an experiment in the realization of God, to regard his hands as God’s hand, his brain as God’s brain, his purpose as God’s purpose. He must regard God as a helpless Longing, which longed him into existence by its desperate need for an executive organ.”
—George Bernard Shaw (1856–1950)