Human Embryo Research Poses Ethics Dilemma

Baltimore nurse Janice Pearse recalls her long quest to become pregnant using in-vitro fertilization through a lens of pain, embarrassment, disappointment--and awe.

The first time her eggs were mixed with her husband’s sperm in a petri dish and the doctor told her that embryos had been formed was an exhilarating moment because “it’s the closest to having a baby you’ve ever been.”

But for every experimentally created embryo that is successfully implanted--and Pearse was one of the lucky ones who eventually became pregnant--thousands of unneeded embryos are frozen in storage--or discarded.

If it is acceptable to create an embryo for transfer into a woman’s uterus--as is now routine in fertility clinics--is it ethical to experiment on an embryo in the laboratory? Or just throw it away?

These are among the more troubling aspects of the new frontier of medical science known as human embryo research.

Many scientists believe that studying the human embryo--at one week a cluster of cells no bigger than the period at the end of this sentence--could yield infinite knowledge about nature’s worst medical scourges.

But like any science involved with creating or manipulating human life, it has become the focus of an intense international debate, and has raised numerous ethical dilemmas that have yet to be resolved.

What, for example, is the moral status of a human embryo? Is it acceptable to make an embryo in the lab only to use it for research--especially when there are at least 12,000 unwanted embryos now frozen in storage and countless others that get tossed away?

How far should research embryos be allowed to develop? At what point does an embryo become a fetus? Moreover, what kinds of research are appropriate--and inappropriate?

The National Institutes of Health last year asked a panel of outside experts to wrestle with these questions, and its members are scheduled to release guidelines for federally funded embryo research Tuesday. Their report will undergo further scrutiny within NIH and be the subject of a public meeting in December. NIH Director Harold E. Varmus will then make the final decision on what areas of research are acceptable for federal funding, and which guidelines should govern the work.

While the panel is expected to endorse human embryo research generally, it will likely propose certain limitations.

It probably will sanction the idea of pre-implantation diagnosis, for example, so parents worried about genetic risks can choose IVF and learn in advance whether an embryo carries an inherited disease. But the panel is expected to deem it unacceptable to use such a technique only to determine sex.

The panel also is likely to oppose cloning, or “twinning,” experiments, and research that uses human-animal combinations. It may, however, conclude that parthenogenesis--a process that uses chemicals or electrical current to stimulate the development of an egg in the absence of sperm--may be valuable in understanding egg development. These so-called parthenotes die several days after they are generated, and do not develop into real embryos.

Regardless of the panel’s recommendations, they almost certainly will be controversial.

Expressing the view of many scientists who are among the chief advocates of the research is Roger A. Pedersen, professor of radiology, anatomy and obstetrics, gynecology and reproductive sciences at UC San Francisco.

Pedersen contends that “a deeper understanding of the biological events of early human development will ultimately have profound implications for virtually all major areas of human health.”

But opponents, arguing with equal passion, maintain that tampering with human life is morally unjustified, regardless of the ultimate medical benefits.

It is “spooky and Frankenstein-esque,” says Rep. Robert K. Dornan (R-Garden Grove), who is leading a congressional effort to derail federal funding for such research. He charges that the NIH “will give rise to a new cottage industry in spare baby parts for its macabre experiments.”

The debate is similar in some respects to one over the use of fetal tissue in medical research. Opponents argued that tissue obtained through abortion, which they deem the destruction of human life, should not be used toward the advancement of medicine, no matter how promising. Upon taking office, President Clinton lifted a ban on federal funding for such research that had been in place since the Ronald Reagan Administration.

The current controversy, however, differs in one vital aspect: A major argument put forth by opponents of fetal research was that it would encourage more women to undergo abortions, which is not an issue here.

Furthermore, the discussion of human embryo research concerns only the study of the embryo outside the uterus, that is, one that is produced in a laboratory by mixing sperm and egg. Such research is conducted on very early embryos, usually those less than one week old--and certainly no later than 14 days. That is the point at which the so-called “primitive streak” appears.

The “primitive streak” is an advancing line of cells that determines the embryo’s head-tail, right-left orientation, and indicates the beginning of the development of individual organs. It is regarded as the transition to a more sophisticated level of development.

Aside from the question of when human life actually begins, many scientists do not regard an embryo as a fetus until it is at least eight weeks old.

In this country, most research involving human embryos has been an adjunct to the clinical practice of in-vitro fertilization and other techniques for helping infertile couples become parents. Most other embryo research has involved the use of animals.

But scientists believe that an increasing emphasis on human embryo research can enhance success rates for reproduction procedures. At present, fewer than one-fourth of the women who undergo in-vitro fertilization will give birth to a child, and then usually only after repeated cycles of treatment.

Beyond reproduction, many in the field also believe that human embryo research can provide new opportunities for understanding the mechanisms of cancer--by studying the ways cells divide--and genetic disorders.

New insights into genetics, for example, could prove critically important both in basic knowledge about how genes work and in determining, before an embryo is implanted into a woman’s uterus, whether it carried a serious genetic disorder. Thus informed, couples could decide whether or not to implant the embryo.

Another potential benefit of human embryo research is as a source of cell lines. Certain cells in the early embryo are stem cells, meaning they have the potential to become any kind of body cell.

This phenomenon raises the possibility that they could be grown and maintained indefinitely in culture in the lab, or even allowed to develop into more specialized types of cells--such as blood, muscle and nervous system cells--which could be used in numerous therapies, such as bone marrow transplantation, repair of spinal cord injuries or skin replacement for burn victims.

Despite these potential clinical applications, the field evokes numerous troubling questions. If parents decide, for example, against implanting a defective embryo for genetic reasons, couldn’t a couple decide against implantation on the basis of sex, which also could be determined in advance?

And what are the boundaries of such research?

Last year, for example, researchers at George Washington University Medical Center here caused an uproar in scientific and ethical circles after they announced that they had experimentally cloned human embryos--that is, divided them into identical twins or triplets. The announcement marked the first time such a feat had been accomplished.

The experiment raised the specter that, since human embryos could be frozen and used later, parents could have a child and then, several years later, have that child’s identical twin. Critics also raised the most extreme example of such work--that parents could have an identical twin years later to serve as an organ donor for the older child.

The angry response caused the researchers to announce they would abandon any further attempts at cloning embryos.

One of the most pressing overall questions is whether embryos should be created solely for the purpose of research.

“I don’t think an embryo is the moral equivalent of a person--but having said that, I do think the human embryo is deserving of some special ethical status,” says Arthur Caplan, director of the center for bioethics at the University of Pennsylvania.

“I don’t think we should treat it as if it were a rock, or an insect, or a leaf,” he adds. “I don’t think you should make them for research. I’m real uncomfortable with that--I wouldn’t create something just to do research on it and destroy it.”

However, he believes that research should be conducted--but only on embryos that already exist, such as those in frozen storage or destined to be discarded. “You’ve got a lot of embryos around that no one wants,” Caplan says. “That is the place to do the research.”

Current regulation of the field is a patchwork of statutes, according to Andrea Bonnicksen, a political science professor at Northern Illinois University who has done research on the subject. Several countries and 10 U.S. states have laws that monitor human embryo research, she says.

California has no such regulations. Louisiana has the most restrictive statute, providing that “no in-vitro fertilized human ovum will be farmed or cultured solely for research purposes or any other purposes.”

Norway explicitly forbids any human embryo research, other than allowing that fertilized eggs be utilized only for implantation in women, and imposes fines and imprisonment on violators. Other countries, such as Germany, Austria, Switzerland, France and Denmark, strictly regulate the research but do not prohibit it altogether.

Britain, Spain and Sweden have more permissive regulations. Britain, where the first “test tube” baby was conceived in 1978, licenses clinics practicing IVF, and each research proposal involving human embryos must be approved by a national-level body.

The U.S. guidelines, when final, will apply only to human embryo research projects that seek federal money and will not affect whatever work is being done privately.

Nevertheless, “public funding could bring such research into a realm where it would receive peer review and be subject to consistent regulation,” says ethicist Lisa Sowle Cahill, professor of theology at Boston College. “This is an important consideration in view of the fact that this research is likely to continue, no matter what future policies are established for government funding.”