Biotext

When is an embryo not an embryo?

A few years ago, I worked on a government inquiry into human embryo and stem cell research. The final report (referred to in the media as the ‘Lockhart Report’ after the chair of the committee, ex-federal court judge, the Hon John Lockhart) was tabled in parliament and was the subject of intense debate.

During the public consultation, I started to think about what image the term ‘embryo’ conjured up for different people, especially in the context of human embryo research. To the scientists and policy makers working in this field, the discussion centred around a fertilised human egg from around the time of the first cell division (ie two cells), through the subsequent few divisions to form a small ball of cells, or blastula. This is the time when IVF embryos are frozen and when scientists can extract embryonic stem cells. However, I suspected that to many members of the public, ‘embryo’ meant a much more developed fetus like those depicted in pregnancy books. I wondered what results you would get if you asked 100 or so people in the street to draw what they thought a human embryo looked like.

Last year at the Institute of Professional Editors national conference I got a chance to test this idea on a group of about 30 of my fellow editors. I asked them to draw the earliest stage of human development that could be called an embryo. Most people drew a typical early fetus, one or two drew a small ball of cells and only one person correctly drew two cells. Interestingly, if I had simply asked them to draw an embryo they would all have been right because the term ‘embryo’ covers the period from the first cell division to eight weeks of development. But the issue for me is that if we are all thinking of something different when we are having a conversation about an embryo then is it hardly surprising that we sometimes appear to be talking at cross purposes. And this is a shame because biology has some good terms for the different stages of embryonic development (zygote, blastula, gastrula, fetus) but these terms have been subsumed within the catch-all term ‘embryo’ and are now difficult to reintroduce without an appearance of changing the ethical goalposts — which is certainly not the intention of this blog! As with many of our topics in this blog, there is more to say … another time.