Part 1: 14 days or 28 – What should be the standard for lab-grown human embryos?

FOr four decades, scientists around the world have imposed a delay in laboratory research on human embryos 14 days after fertilization. This is known as the 14-day rule. This examination is done outside the uterus in petri dishes, test tubes, or by examining early cells under a microscope.

This is part one of the second part series. Read Part Two on Wednesday, September 28.

Until recently, research after 14 days was only a theoretical issue, as scientists didn’t have the tools to keep experimental embryos alive much longer. But this has changed. technology It is now available to extend the fetus’s survival in the laboratory. As a result, a fierce debate arose about whether to expand the allowed search window to 28 days.

Human embryo growing in the laboratory for 12 days, showing cells that will form the embryo itself (purple). Credit: Antonia Weberling, Billy Weatherby, Carlos Gantner, Magdalena Zernica Goetz

An increasing number of proponents claim that the extra two weeks will bring significant scientific benefits. sHuman embryos at this stage of development are studied It can provide important information, such as why the miscarriage occurred and Why birth defects and Genetically derived malignancies occur. It can increase a better understanding of how primitive tissues and early organs develop, including the nervous system (which appears only after the second or third week after fertilization). Human embryos are also important to stem cell research, as researchers develop cell-based therapies to treat human diseases.

“[I]It is now safe and timely to make a change in policy and broaden the base without fear of any ‘moral and regulatory’ slippery slope Sophia McCauley, an influential bioethicist and member of the British Pharmaceutical Society, wrote in Journal of Medical Ethics in 2021.

But not everyone agrees. Philosopher Anna Smagdor, a bioethicist at the University of Oslo, is challenging the push to extend the 14-day rule. The arguments she and other critics make are social and philosophical, not biological or research oriented. Nobody gets hurt by the current standard, she says, and so there’s no reason to change it.

Either position – keeping or extending the 14-day deadline – raises fundamental scientific and ethical questions about experimenting with embryos: on what basis should we decide and who should make the decision?

Different laws around the world

With clinicians, scientists, and ethicists promoting different analytical frameworks, agendas, and viewpoints, science is at an impasse. The main problem is that there is no agreed, objective way to guide countries in assessing whether or not to revise the existing standard. (The same issue bothers us about similar issues arising from new technologies, such as allowing human genetic engineering or human cloning for reproductive purposes.)

Last year, the British-based International Society for Stem Cell Research (ISSCR), widely considered the official voice of the stem cell community, announce It no longer supports the prevailing international standard for 14 days.


Previously revised in 2016, the ISSCR standard has long provided an assessment model for what the biomedical community agrees on, and which projects are prohibited. He recommended that “national academies of sciences, academic societies, funders and regulators” around the world engage the public in conversations about scientific topics and issues and whether the two-week limit should be extended depending on research goals.

The guidelines have always carried extraordinary weight globally. In the United States, there is no federal law regulating research on embryos (as is also the case in the IVF industry, which is often unregulated). However, in a non-binding opinion issued in 1979, the Department of Health, Education and Welfare’s Ethics Advisory Board endorsed a voluntary 14-day rule.

similarly, Canada, China, India, Japan and Spain allow up to 14 days of trial, although their positions are established by law. Other countries are taking more extreme positions, for and against.

On one extreme of the policy spectrum, Austria, Germany, Italy, Russia and Turkey prohibit research on human embryos. The The Oviedo Convention (Bioethics) From the Council of Europe with 35 signatories, 29 of which have ratified, completely opposed to embryology research. The Netherlands, while not a signatory, currently agrees, although it is in the process of revising its law, to Dutch Embryology Law.

On the other end of the policy spectrum, Brazil and France have not set time limits. This may be a harbinger of research tourism, as scholars may be looking for countries with relaxed legal restrictions.

The debate is fiercest in the UK, where the ISSCR is based. Embryo research (along with IVF procedures and practices) is governed by the Human Fertility Act, which was first enacted in 1990. The 14-day standard has been comprehensively revised. 2017 Nuffield Council Report on Bioethics. Now, some British scholars and ethicists are calling for the HFA to be modified and watered down. John Appleby he is Lecturer in Medical Ethics at Lancaster University:

We now know more about embryology than we did more than 30 years ago when the law came into effect. It now makes moral and scientific sense to extend the permissible window for embryo research to 28 days (ie the “28-day rule”). Thus, maintaining the status quo of the 14-day rule is by no means an ethically neutral option.

Should policy makers seek guidance from philosophers, ethicists, lawyers, scientists, or the public?

In the UK and some European countries, government relies on philosophers and lawyers to formulate policy – Ma Sheila Jasanoff, Harvard University Professor of Law and Society, called “formal bioethics”. (Something similar happens in the United States with regard to health insurance decisions, although the issues are more mundane and revolve around politics and economics rather than bioethics).

But the way scholars base their recommendations is nothing but an organized, standardized, authoritative, or even widely accepted method in the philosophical community, argued the late Mary Warnock, the British philosopher of morals, education, and reason.

Mary Warnock at her home in Wiltshire, England, 2003. Credit: Neil Turner/New York Times

Warnock is bKnown for chairing the 1984 commission whose report formed the basis of the British Human Fertilization and Embryology Law (1990 as amended). She spent decades exploringWhere do you draw the lineArguing that the public “has a right to know, and even control” professional practices.

But do you know what? And what tools will the public use to evaluate researchers, let alone “control”?

In a sense, the 14-day rule that she and her committee passed – which also forms the basis of the HFA’s latest decision on the issue – was based on something akin to “gut ethics”. Warnock herself admitted that she could not reconcile the different views of the panelists when she first revealed her recommendation, and invited the public to speak:

[M]Aimen philosophers … he could not shake off the belief that morality is a set of often incompatible and subjective opinions and premises. [Some said] “Look at the benefits” and [others] … at the other end, [some] “I don’t care what the benefits are: I feel it’s wrong…” he said.

Jasanov agreed with Warnock. She also wants “community” (the common people) to take control of the investigation. But if scientists and ethicists have such differences, one wonders how the public will deal with this issue.

Barbara Pfeiffer Belor, Master of Laws (Private Health). Professor of Law and Bioethics in the International Bioethics Program at the University of Porto and Research Professor of Scientific Statecraft at the Institute for Global Policy in Washington, DC.

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