Is A Fetus Part of the Mother’s Body?
How often have you heard it said that “A fetus is just a tissue in the mother’s body and the mother has a right to do whatever she wants with her own body”?  Or perhaps, “A woman has the right to an abortion since the fetus is nothing more than a tissue belonging to the mother’s body.”  The following newspaper article, submitted by a reader, discusses the scientific evidence that the fetus is a foreign body inside the mother’s womb and is not a tissue belonging to the mother’s body after all.  The mother’s body detects the foreign tissue and her immune system tries to destroy the fetus.  Only because of an enzyme generated by the fetus is it possible for the fetus to survive in the hostile environment and live to be born into the world outside.

“Fetus Secretes Enzyme to Survive in Mother, Study Indicates”
            -- from the Los Angeles Times (reproduced from the Sacramento Bee of August 21, 1998).

Los Angeles -- Researchers may have solved the enduring mystery of how a fetus is able to evade its mother’s immune system for the nine months of pregnancy -- a discovery that could lead to new drugs to prevent transplant rejection, to help women who have difficulty conceiving, and even to induce abortions safely.

Normally, the human immune system reacts against any foreign tissue in the body and tries to destroy it.  And because half of an infant’s genes come from the father, “we are transplants for the nine months of our lives before we ever come out into the world,” said Dr. Andrew L. Mellor, who led the research.  “Our discovery addresses the paradox of how mammals, including human beings, survive in the potentially hostile environment of the womb.”

Scientists have long believed that the developing fetus avoids destruction because the mother has a protective mechanism that somehow creates a “privileged” site -- the womb -- where rejection doesn’t occur.

The research indicates the fetus creates a privileged site by mounting a guerrilla operation against the mom’s immune cells by secreting an enzyme that blocks a key component of the immune response.

Inadequate production by the fetal cells of the enzyme, indoleamine 2,3-dioxygenase, known as IDO, may play a key role in spontaneous miscarriages, according to research that the Medical College of Georgia team reports today in the journal Science.

If that can be demonstrated, Mellor said, it may well be possible to develop drugs that mimic the action of IDO or stimulate increased production of the enzyme.

Alternatively, it might be possible to administer IDO inhibitors to provoke a miscarriage when an abortion is desired.

Interfering with tryptophan metabolism to protect a transplant may be more difficult because the amino acid is required throughout the body.  But when researchers learn how the lack of tryptophan results in tolerance, they will almost certainly identify a biological pathway that can be attacked at other points.

“That’s probably where the real opportunity would exist for clinical application,” said Dr. Robertson Parkman of the University of Southern California.

The task now, Parkman said, is to completely understand the biological pathway in the hope of finding places to interfere with it to protect transplanted organs.


Editor's Note:  As this article indicates, whatever people may wish to think, the mother’s body thinks that an embryo is not a part of “self.”  Whatever is not “self” is looked on as an invader.

Some proponents of abortion tend to claim that, first of all, the fetus is not a human, so it is not murder to abort the fetus.  Well, then, if the fetus is not human, what is it?  The answer has generally been that it is merely a growth within the mother’s body; therefore, if it is part of the mother’s body, it is up to the mother whether to have this “lump” removed.  The article quoted above tends to take some of the strength out of that argument.