Stem cell terminology: practical, theological and ethical implications.

• Author: Shanner, Laura
• Position: Canada

Abstract

Stem cell policy discussions frequently confuse embryonic and fetal sources of stem cells, and label untested, non-reproductive cloning as "therapeutic." Such misnomers distract attention from significant practical and ethical implications: accelerated research agendas tend to be supported at the expense of physical risks to women, theological implications in a multi-faith community, informed consent for participation in research, and treatment decisions altered by unrealistic expectations.

When public discourse lags behind scientific developments, errors commonly become entrenched in ethics and policy development. Lessons that we have learned in previous contexts are also frequently lost in the excitement over new breakthroughs. In the stem cell debate, common errors include confusing technology regarding types and sources of stem cells, and types and purposes of cloning. These seemingly minor errors of terminology nevertheless may have significant ethical force: explicitly clear definitions for RGTs (reproductive and genetic technologies) are essential to promote policies that are neither overly restrictive nor unintentionally broad, and to avoid entrenching unchallenged assumptions or vested interests. Failure to employ appropriate terminology may encourage unintended injury to women, mask legitimate points of debate in a pluralistic society, undermine fully informed consent for participants in research trials, and inappropriately influence treatment decisions for individuals seeking remedy f or their illnesses.

1. Sources of Stem Cells

   The U.S. National Bioethics Advisory Commission, (1) the Canadian Institutes of Health Research, (2) and others have employed the acronyms "ES," for embryo stem cells, and "EG" for "embryo" germ cells, which actually come from aborted fetuses. Referring to both sources as "embryos" is mistaken biologically, but also masks health implications for women and may disguise a variety of theological concerns in a multicultural community.

   In the blastocyst stage at five to seven days of embryonic development, an inner cell mass has diverged from the precursor to the placenta; cells from the inner cell mass may still give rise to any body tissue, and are therefore highly attractive for stem cell cultures. However, the embryo is destroyed when the inner cell mass is isolated to generate a stem cell line. Such cells are appropriately referred to as "embryo stem" or ES cells.

   So-called "EG" cells are the primordial germ cells (precursors to ova or sperm) retrieved from an aborted fetus aged approximately nine to 13 weeks. The distinction between embryos and fetuses occurs at nine weeks of development, when all rudimentary organs and body structures are present. When fetal germ cells are called "embryo" germ cells, a fundamental biological misunderstanding becomes entrenched. Instead, they should be called fetal stem (FS) cells or fetal germ (FG) cells. The distinction of embryos and fetuses is ethically important for two reasons.

   I.a. Implications for Women's Health

   Embryo or fetal tissue research of any form must always be considered a women's health issue, because embryos and fetuses can only be accessed following invasive procedures in women's (but not men's) bodies. Embryo and fetal tissue research must also, therefore, be considered in light of anti-discrimination protections between women and men. Bill C13 (3) rightly notes the differential impact of RGTs on women in s. 2(c), which states:

   2. The Parliament of Canada recognizes and declares that

   (c) while all persons are affected by these technologies, women more than men are directly and significantly affected by their application;

   The implications for women's health - as infertility patients, ovum donors or abortion patients - differ significantly with the type of cells and the developmental age of the source. In vitro embryos are located outside a woman's body, following the retrieval of ova from her body, while fetuses are located inside the womb until after an abortion.

   We must ensure that a woman's own fertility treatments have been completed optimally before we approach her to donate ova or embryos for research purposes; financial incentives and the desire to be a "good patient" may compromise patient consent and the therapeutic relationship. (4) Healthy women donating ova specifically for research must be protected from the risks of ovarian hyperstimulation...