Pregnancy is the time begins at conception and ends when the 'baby' is either born or aborted. The definition of conception being the time of fertilisation changed in the 1970s to mean the time of implantation.The woman's normal menstrual cycle is a balance between estrogen and progesterone, two female hormones whose production in the ovaries is regulated by stimulating hormones from the pituitary gland -- a gland about the size of a grain of rice which sits at the base of the brain, between the optic nerves.
- The redefining of pregnancy was to accomodate IVF treatments when fertilisation takes place outside the womb.
- It was to avoid ethical and legal questions about the morality of terminating early human life.
- The term 'pre-embryo' was first used in 1979 by a bio-ethicist and a biologist.
- It is mainly in the writings of bio-ethicists, not scientists, that the term 'pre-embryo' is used.
- Cells from unborn babies may help to heal wounds in their mothers both before and after pregnancy.
In a normal cycle, when the balance between estrogen and progesterone is just right, an egg ripens and bursts out of the ovary into one of the fallopian tube through which it descends toward the womb.
If it meets a sperm within twelve hours or so, it is fertilized and becomes a unique genetic human being. This new human being continues to develop for a few days, then implants in the lining of the womb, from which it draws nutrition until birth.
Release of the egg from the ovary is called ovulation. The union of egg and sperm is called conception and the nesting of the developing embryo in the wall of the womb is called implantation.
Pregnancy begins at fertilisation (conception), when egg and sperm, each carrying 23 chromosomes, unite to create a new person, genetically distinct from mother or father, with a unique immune identity. Sperm carries the x or y chromosome that determines the gender of the newly conceived human being.
Normally, the developing person soon neutralises the mother's immune rejection and they co-exist peacefully.The mother’s immune system notices that a foreign person is present, within a day or two of conception, and attempts to reject the little cluster of cells. Normally, the developing embryo neutralises the mother's immune rejection and they live in peace throughout pregnancy.
Attempts to redefine pregnancy as beginning at implantation are not scientifically accurate. The medically unique event is conception.
The re-defining of implantation to be when "pregnancy" begins, was initiated to accommodate the introduction of the process of in vitro fertilization, where fertilisation takes place artificially outside the mother in a petri dish. The embryo is then artificially introduced into the woman's uterus so that implantation of the embryo can take place.
Obviously, if the embryo is not within the woman's body, she is not "pregnant" in the literal, traditional sense of the term. However, this artificial situation cannot be used, with any validity, to redefine "normal pregnancy, " in which fertilization does take place within the woman's body in her fallopian tube. Subsequently, the embryo moves along the tube to implant itself into her uterus.
Medical organisations and legislative bodies came to accept the new definition even going so far as to say that conception began at implantation and some of the leading textbooks of Obstetrics also now regard conception as synonymous with implantation. This is why many birth control methods are regarded as contraceptive rather than abortifacient.
The new definitions of conception and the beginning of pregnancy were not the result of new scientific information.
In normal situations, pregnancy begins at fertilisation, not at implantation. The new definitions of conception and the beginning of pregnancy were not the result of new scientific information about these phenomena. Rather, they were intended as a means of avoiding difficult ethical and legal questions about the morality of termination of a human life in the early stages of its development.
It is interesting to note that a 'wanted' pregnancy is counted from the first day of a woman's last period. This means that at conception, the foetus is already considered to be two weeks old.
The term 'pre-embryo' goes back to 1979 when it was first used by a bio-ethicist Jesuit theologian Richard McCormick in his work with the Ethics Advisory Board to the United States Department of Health, Education and Welfare, and those of frog developmental biologist Dr. Clifford Grobstein in a 1979 article in Scientific American, and most notably in his classic book, Science and the Unborn: Choosing Human Futures (1988).
McCormick and Grobstein continued propagating this new terminology as members of the Ethics Committee of the American Fertility Society, and in numerous influential bioethics articles, leading to its common use in bioethics, theological, and public policy literature to this day.
The term "pre-embryo" was also used as the rationale for permitting human embryo research in the British Warnock Committee Report (1984), and then picked up by literally hundreds of writers internationally, including, e.g., Australian writers Michael Lockwood, Michael Tooley, Alan Trounson and especially by Peter Singer (a philosopher), Pascal Kasimba (a lawyer), Helga Kuhse (an ethicist), Stephen Buckle (a philosopher) and Karen Dawson (a geneticist, not a human embryologist). Note that none of these is a scientist, with the exception of Karen Dawson, who is a geneticist.
It is mainly in the writings bioethicists that so much incorrect science is claimed in order to "scientifically" ground the "pre- embryo" myth.It is mainly in the writings of bioethicists that much questionable science is claimed in order to "scientifically" ground the "pre-embryo" myth and therefore "scientifically" justify issues such as abortion as well as the use of donated or "made-for-research" early human embryos in destructive experimental human embryo research (such as infertility research, cloning, embryonic stem cell research, the formation of chimeras, etc.).
Scientists, in trying to "reach" young students in a more familiar language, sometimes use popularised (but scientifically inaccurate and misleading) terms themselves.
Potential Human Being
Bioethicists, research scientists, pharmaceutical companies, and other biotech research companies claim that the 'pre-embryo' is only a 'potential' human being.
Prof Lejeune, the world-renowned French geneticist testified on this issue at a Court hearing : “We don’t use ‘potential’ in medical science. As soon as the genetic information is at work, then the human being begins to express itself. Then it forms the external features that we recognise, but it is the same human being from conception to senility.”
“The child is the potential of the teenager, the teenager is the potential of the adult, and the adult of the old man. It is the same human being at different states of life – developing itself from the beginning up to its finished product.”
The immediate product of fertilisation is a human being, - the zygote. Science tells us that this zygote is a newly existing, genetically unique, genetically male or female, living human being - it is not a "potential" or a "possible" human being. And this developing human embryo, is a human being, whether or not it is implanted artificially into the womb of the mother.