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late from such creatures to man. Thus the genetic code as we know it is universal and with only elaboration of detail, the fundamental genetic mechanisms are also universal.
I am an elected member of the Academy of Arts and Sciences and the National Academy of Sciences and have been a member of a number of government advisory bodies including one in which I just completed my role as Chairman of a Committee to review a large area of research under the auspices of the National Cancer Institute. I have been privileged to receive several awards and honors from my colleagues. I am currently Professor of Genetics at the Rockefeller University.
Now to the matter at hand. To the biological scientist, life can only be defined as a capacity to grow and reproduce. It is a continuum. What I mean by that is that no living form arises spontaneously and that only living forms can give rise to living forms. Thus in every sense that we can understand it, an unfertilized ovum and the spermatozoa which might fertilize it must be considered alive. They are as alive as any bacterial culture growing in my laboratory or every bit of tissue growing in a flask.
Viruses, the simplest of living creatures, can almost indefinitely await the arrival of an appropriate host cell and then in a brief period of time multiply to give rise to hundreds or thousands of progeny. Spores and seeds of many organisms await the appropriate environment to germinate and give rise to organisms like their progenitors. One could go on indefinitely describing the different reproductive modes of the manifold species that inhabit this earth, but this would add nothing to the matter before you.
I know that it has been argued that the individual and unique genetic identity of a conceptus occurs at the moment of fertilization or shortly thereafter. Indeed, barring certain genetic accidents, as far as we know now, this is true, but is no more true for humans than for any other sexually reproducing species, from animals to plants. Scientifically speaking there is no evidence of any qualitative difference between fertilization in humans and fertilization in any other organism. Since you are not here discussing the issue of abortion in any organism other than man, it is clear that there must be something else involved; some special property ascribed to humans which makes this question so difficult. What constitutes this special property is a matter of opinion and religious belief and not a matter of science. There is nothing uniquely human about the union of sperm and egg. Scientifically we cannot answer the question of when life begins. To answer the question thus becomes purely a rhetorical ploy. It is a matter whose definition can be exploited by any partisan who wishes to impress his views upon his fellows.
The more focused and rational question is when can the fetus live independently of the mother? On this question I have no special competence not being a physician, but it is generally accepted that this occurs late during the third trimester of pregnancy. Until that time the fetus depends totally on the mother for nutrition, oxygen, the removal of waste products of metabolism and perhaps unknown developmental signals; contributions which are required for the full realization of its potential.
Thus if we use the word “living" as applied to humans, to decide what may and may not be done, we come to the absurdity of having to save every ovum that each mature female produces every month and the billions of spermatozoa continuously produced by the mature male.
What are the consequences of restricting abortion? The pregnant woman is forced to have a child which she doesn't desire—her health, mental and physical, can be put in jeopardy. I will not touch on the issue of the effects of illegal abortion and the special hardships imposed upon the poor and underprivileged. Others, I'm sure, have testified on these matters. However, as a geneticist I am concerned about the restriction that it would impose on abortion for those genetic diseases for which we have no treatment and for which diagnosis can be made in utero. The option of the family to decide whether or not to bring a defective child into the world would be lost. Each year as our understanding grows, it becomes possible to diagnose more and more specific genetic diseases before the birth of a defective child, particularly those involving chromosomal and enzymatic abnormalities. This is accomplished by removing a little of the amniotic fluid from the pregnant woman's uterus and examining the cells it contains. Thus today, Down's syndrome or Mongolism, which is caused by the presence of an extra chromosome, as first described by Dr. Lejeune, could be essentially eliminated by such testing and abortion of
the affected fetus. A number of other genetic diseases can be circumvented in this way, thereby preventing untold misery for parents and heavy burdens on society.
As a scientist but even more as a concerned human being, I can only appeal to the members of this Committee not to impose the beliefs and opinions of particular groups on society as a whole. There is not-nor need there ever be a requirement that any individual have, or participate in performing, an abortion. Such decisions in a free and democratic society are best left to the discretion of the parties directly concerned.
Senator Bays. Thank you, Dr. Zinder.
STATEMENT OF JOHN D. BIGGERS, PROFESSOR OF PHYSIOLOGY,
AND MEMBER OF THE LABORATORY OF HUMAN REPRODUCTION AND REPRODUCTIVE BIOLOGY, HARVARD MEDICAL SCHOOL
Dr. BIGGERS. Senator Bayh, members of the committee, my name is John D. Biggers, professor of physiology and member of the laboratory of human reproduction and reproductive biology, Harvard Medical School. I was honored to receive an invitation to appear before the Senate Subcommittee on Constitutional Amendments to discuss the proposed amendments to the Constitution of the United States by Senator Buckley and Senator Helms.
First, let me establish my credentials. In 1952, the University of London awarded me the degree of doctor of philosophy, and in 1956, the degree of doctor of science in recognition of my contributions to the reproductive and developmental biology. I have been honored by being elected Commonwealth Fellow of St. John's College, University of Cambridge, England, for the year 1954–55, and in 1973, as the Upjohn lecturer of the American Fertility Society.
Before my appointment to the Harvard faculty, I was professor of population dynamics at the Johns Hopkins School of Hygiene and Public Health, president of the society for the study of reproduction, and member of the reproductive biology study section of the National Institutes of Health.
Presently, I am a consultant to the expanded program in Human Reproduction of the World Health Organization, editor in chief of the scientific journal, “Biology of Reproduction", and director of a program-project awarded to Harvard University, supported by the National Institute of Child Health and Human Deevlopment, concerned with the physiological mechanisms involved in the establishment of pregnancy. I am also actively concerned with the problems of developing safe, acceptable, efficient methods of contraception.
Mr. Chairman, in my testimony I wish to refer to some drawings in the presentation. I think you have these in front of you.
The alternative amendments proposed by Senators Buckley and Helms both have the aim of bringing abortion to an end under the law. Senator Helms is the spokesman of those who firmly believe in the principle that: “Abortion, the deliberate destruction of an unborn human being, is contrary to the law of God and is a morally evil act.” If this principle is granted axiomatic status, it naturally follows that abortion cannot be tolerated under any circumstances.
The direct approach available to those who wish to legalize their objections to abortion is to advocate specific antiabortion laws. The
indirect approach, exemplified by the constitutional amendment proposed by Senator Helms, is to make abortion illegal by insisting that the unborn child from the time of fertilization has the legal rights, without exception, accorded by due process of the law and equal protection under the laws.
Mr. Chairman, I believe it is essential to determine what is the critical question before your committee. The primary question, as I see it, is whether it is necessary to insert into the Constitution of the United States an article providing legal protection for an unborn child from the time of fertilization. The assessment of such a proposal must take into account all of the multiple effects of such an action. Although inserting such an amendment is one means of overturning the recent legalization of abortion by the Supreme Court, direct specific measures might be more appropriate if you are convinced that legalized abortion must be abolished.
In my testimony, I wish to discuss two main topics which I believe to be relevant to your deliberations. The first is to indicate some of the many unsatisfactory consequences which will arise if the amendments are adopted. Second, to discuss briefly some aspects of the circumstances where the termination of embryonic life may be justified. I believe it is important to do this since many people, including myself, are not persuaded that abortion is necessarily a morally evil act.
I believe that granting legal rights to the unborn child will have profound implications in several extremely important medically related areas:
One: The practice of fetal medicine, and the research necessary for its advancement.
Two: The practice of genetic counselling.
Three: The practice of contraception and family planning. Four: The effectiveness of foreign-aid programs involving family planning in developing countries, supported directly by the U.S. Government and private agencies, and indirectly through the United Nations Population Fund.
Five: The personal conduct of all pregnant women and all women exposed to the possibility of being pregnant.
Harriet Pilpel has also pointed out the many legal complications of adopting Senator Helms' amendment, and these are described in a recent issue of "Family Planning Perspectives”.
Mr. Chairman, this catalog of potentially affected areas clearly demonstrates the scope of the intricate ethical, social, legal, and medical questions raised by the proposed constitutional amendments. I hope, therefore, that your subcommittee will hear testimony from experts dealing with all these areas before reaching any decisions on the proposed amendments.
Let me amplify these general comments by considering in detail two questions:
When does a woman become aware she is pregnant?
What is the biological relationship between the mother and the unborn child?
First, I must describe briefly what occurs during the establishment of pregnancy. In the first figure I shall indicate the parts of the female organs. The parts are indicated on the right side of the diagram, and on the other side I indicate some of the functions that take place in those different parts. At the time of ovulation an egg or ovum is shed from one or the other ovary into the upper part of the adjacent oviduct. At the time of intercourse, about 200 million male germ cells, called spermatozoa, are deposited in the vagina. These calls then begin to migrate up the female genital tract to the upper regions of the oviduct.
We know very little about the process in women, and we have to extrapolate from studies on experimental animals. However, it seems that only a very few sperm reach the upper part of the oviductapproximately 100, 200.
Should sperm reach the upper part of the oviduct at approximately the time when ovulation occurs, conditions are set for fertilization. This process involves the fusion of the ovum with one sperm. Figure 2 shows the stages involved in the fertilization process.
The sperm first penetrates a series of barriers around the ovum. Those are figures of the corona cells and the zona pellucida. It then fuses with the membrane of the ovum and its nucleus enters. The sperm nucleus soon swells and forms the male pronucleus.
I wish to stress that fertilization is not something that occurs at a fixed point in time. Rather, it is a process spread over time. Its duration will depend on the arbitrary definition of when it begins and ends. As I have described it, the duration is about 4 to 5 hours. Moreover, the ovum is fertilizable for several hours after ovulation.
Figure 3 shows that following fertilization, the ovum begins to divide repetitively, so that eventually a ball of cells is formed. This structure then hollows out to form a fluid-filled cyst called the blastocyst.
While these initial developmental changes are taking place, the early embryo journeys down the oviduct to the uterus. We do not know exactly how long this journey takes in the human, since early embryos of known age are rarely recovered from the female reproductive organs.
However, from the meager evidence available, we can roughly estimate that the journey takes about 4 days. Soon after entering the cavity of the uterus, the blastocyst attaches to and invades the wall of the uterus-a process called implantation. Prior to attachment, the early embryo lies free within the mother's genital tract and we accordingly speak of the “free-living” or preimplantation stages of pregnancy.
The blastocyst consists of two main parts. On one side, it is thickened-a region called the inner cell mass where the body of the embryo develops. The remainder is the trophoblast, which interacts with the wall of the uterus to form the placenta. The placenta is a transitory organ, discarded at birth, through which the vital processes of nutrition, respiration and excretion of the embryo take place.
I would like to stress that implantation is not something which occurs at a fixed point in time. Rather, it is a process spread over time. In women, it is spread approximately over the 5 and 6 days after the day when fertilization occurs.
I now return to my original question: When does a woman become aware she is pregnant?
I wish to distinguish between becoming "physiologically aware” and becoming "consciously aware” of being pregnant. Figure 4 demonstrates some essential relationships.
It is convenient to describe the temporal relationships between events in early pregnancy by taking the first day of menstrual flow prior to ovulation as zero time, that is, day zero. In an average woman, ovulation occurs 14, 15 days later. If the ovum is not fertilized, it eventually dies and on the 28th day, the expected menstrual flow occurs. In this way, the menostrual cycle is repeated.
If the ovum is fertilized, it proceeds to divide and commence its journey to the uterus, which it enters on about day 19. Soon after the arrival in the uterus, the embryo attaches to the uterine walls and begins to implant, a process that occurs during the 19th, 20th day, depending on how one chooses to define the beginning and end of implantation.
It is near the beginning of implantation that a signal passes from the embryo to the mother which causes a switch in her reproductive function from the nonpregnant to the pregnant condition. As a result, the menstrual cycle is interrupted so that the expected menstrual flow on the 28th day does not occur. Thus, a woman does not switch her physiological functions to the pregnant state until the time of implantation. Prior to this, the pre-implantation embryo lies unattached in the mother's reproductive tract. As far as the mother is concerned physiologically, pregnancy does not start until implantation.
However, it is important to realize that a woman does not become consciously aware of being pregnant until later. The earliest sign is a missed menstrual period, but this is not a certain criterion since the menstrual period does not always follow a regular cycle or ceases for other reasons.
During the early stages of pregnancy, if a woman cannot know she is pregnant, is it reasonable to legislate for the protection of the embryo?
Should the mother be held responsible for any misfortune experienced by the embryo during this time?
If such legislation is written, every woman who is sexually active will have to assume she is pregnant and modify her behavior in a suitable way. Since the average duration of sexual activity needed to become pregnant in normal healthy women not using contraception is 4 to 5 months, this phase of uncertainty will be considerable.
It can be suggested that pregnancy tests could be used. At present, the earliest stage at which pregnancy can be detected is about day 24. At this time, a sample of maternal blood contains the beta subunit of human chorionic gonadotropin, a protein hormone produced by the embryo. This date is 4 to 5 days after implantation.
It is possible that tests detecting pregnancy even earlier will be developed. In the last week or so in the popular press there have been reports that this may be so. But then it takes you back to approximately the end of implantation. But in any case, to make such tests available to all sexually active females for every menstrual cycle would be prodigious undertaking.
You should realize that in order to make the point that there is an initial phase lasting several days after fertilization when a woman