‘Excess’ Embryos for Human Pluripotent Stem Cell Research

Pamela White argues that ‘excess’ embryos potentially available for human pluripotent stem cell research should not be described as ‘unwanted’.

In September 2013, the Panel on Research Ethics released proposed revisions to the 2nd edition of the Tri-Council Policy Statement: Ethics Conduct for Research Involving Humans (TCPS2). The public consultation ended January 15, 2014.

Among the proposed revisions is the planned integration of the CIHR Updated Guidelines for Human Pluripotent Stem Cell Research into the TCPS2.The planned integration is a welcome revision, long advocated by prominent Canadian scholars. The draft text, however, carries over a problem with the original CIHR guidelines. Embryos no longer needed for personal reproductive use are wrongly described as ‘unwanted’ embryos. This wording needs to change.

pinkembryoEmbryo cryopreservation is now standard medical practice as in vitro fertilization (IVF) frequently produces embryos in excess of the immediate reproductive needs of the individuals or couples for whom they were created. In Canada, the Assisted Human Reproduction Act (Section 8 Consent) Regulations require that patients be informed of the possibility that excess embryos may be created, prior to the commencement of their fertility treatment. It is estimated that about 1/3 of Canadian IVF patients cryopreserve and store excess embryos.

Embryo cryopreservation benefits patients by providing a reassuring genetic insurance policy. Yet for many it also produces an unanticipated ethical conundrum: What should be done with cryopreserved embryos no longer required for personal reproductive use? A growing body of literature suggests that decisions about the disposition of cryopreserved embryos are stressful and potentially problematic for many individuals and couples.

In Canada, prior to the creation of human embryos, individuals and couples consent to the disposition of possible future excess embryos. Options include reproductive use by a third party, improving assisted reproduction procedures, and providing instruction in assisted reproduction procedures. After embryos are created, an additional option is available, which is donation for “a specific research project, the goal of which is stated in the consent”. The research option clearly includes research to derive human embryonic stem cell lines.

A problem with the guidelines for pluripotent stem cell research that are to be integrated into the TCPS2 is the ongoing description of ‘excess’ as ‘unwanted’ embryos. ‘Unwanted’ is an inaccurate characterisation of these embryos.

Interestingly, the French language version of the proposed human pluripotent stem cell research guidelines does not use this inappropriate descriptor. In French, excess embryos are described as supernumerary (surnuméraire), not ‘unwanted’. To say the least, the English and French versions of the CIHR guidelines should be equivalent. In this instance, equivalence would best be achieved by common use of the descriptor supernumerary – a more neutral term than the value-laden term ‘unwanted’.

The proposed stem cell research guidelines should also reflect the wording and phraseology used by couples and individuals who actually have to decide about the donation of cryopreserved embryos no longer needed for their own fertility treatment. A review of the terms used by persons interviewed as part of a CIHR-funded study on patients’ views about the donation of eggs and embryos for scientific and clinical researchsheds light on how those who have had to make decisions about the retention and disposition of cryopreserved embryos described the embryos no longer needed for their reproductive use.

Below is the opening question asked of study participants:

1. At what time during your fertility treatment were the options for embryos that were no longer wanted for reproductive use discussed with you?

1. À quel moment au cours de vos traitements de fertilité a-t-on discuté avec vous des options pour les embryons dont vous n’aviez plus besoin à des fins de reproduction?

Despite the fact that the question (in English) makes reference to “embryos no longer wanted for reproductive use” none of the study participants referred to their stored embryos as ‘unwanted.’ They described their embryos as: excess, leftover, surplus, spare, extra, (supplémentaire, surnuméraire), not used, (pas utilisé), and not needed, (plus besoin). Indeed, only one study participant ever characterized embryos as unwanted, and the reference was rhetorical: “It is not like you drop the embryos off at the clinic for unwanted embryos.”

People don’t think of their embryos as ‘unwanted’; just no longer needed for their own reproductive use. The Canadian guidelines for research involving pluripotent stem cells should reflect this difference and replace the term ‘unwanted’ with ‘supernumerary’.


Pamela M. White is a Specialist Associate Lecturer, Kent Law School, University of Kent.


  1. […] 'Excess' Embryos for Human Pluripotent Stem Cell Research … […]

  2. […] 'Excess' Embryos for Human Pluripotent Stem Cell Research … […]

  3. […] 'Excess' Embryos for Human Pluripotent Stem Cell Research … […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: