JANICE PEARSE, a nurse in Baltimore, Md., recalls her long
quest to become pregnant using in vitro fertilization.e
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," she said.
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 done in fertility clinics - is it
ethical to experiment on an embryo in the lab? Or just throw it
These are among the 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
But like any science involved with creating or manipulating
human life, studying the human embryo has become the focus of an
intense international debate and has raised numerous ethical
What 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 embryos
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?
What kinds of research are appropriate?
Last year, the National Institutes of Health asked a panel of
outside experts to wrestle with these questions. Today, its members
are scheduled to release guidelines for federally funded embryo
research. The report will undergo further scrutiny within the
National Institutes of Health and be the subject of a public
meeting in December. Harold Varmus, who heads the institutes, will
then make the final decision on what areas of research are
acceptable for federal funding, and which guidelines should govern
Although the panel is expected to endorse human embryo
research, it probably will propose certain limitations.
The panel is expected to sanction the idea of pre-implantation
diagnosis, for example, so parents concerned about genetic risks
can choose in vitro fertilization 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
The panel also is likely to oppose cloning, or "twinning,"
experiments, and research that combines human and animal tissue.
But the panel may 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
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 professor Roger A. …