Designer babies and IVF: dispelling the sci-fi myths

05 Jan 2016

‘Designer babies’ have been the stuff of science fiction for decades, without ever getting close to becoming reality. In recent years however, with new scientific developments, techniques and amended laws, some have reignited the debate surrounding ‘designer babies’. But are we in fact any closer to a world of pre-designed babies or do these remain a thing of sci-fi legend?

Are ‘designer babies’ already a reality?

Some commentators would argue that not only are designer babies possible, they are already a reality. They point to the use of techniques such as pre-implantation genetic screening (PGS) and pre-implantation genetic diagnosis (PGD) as evidence of this. These methods are used to screen embryos for specific conditions (such as cystic fibrosis and Huntington’s disease), as well as to check that they have the correct number of chromosomes. PGD can also be used to identify embryos to become saviour siblings for sick children needing transplants. 

Some believe that this is a form of eugenics in itself, as children are selected to exist or not on the basis of their genes. However, In the UK, this process is limited to selection of embryos on the basis on aneuploidy or disease status. PGD is most often used to avoid debilitating genetic disease, and PGS is usually used to find normal embryos. In both circumstances, the aim is not to edit or to produce so-called ‘superior’ human beings; it is merely to best ensure a healthy, normal baby.

In some countries, such as the US, PGD is also permitted for non-medical uses such as gender selection. In these instances the social and ethical problems are more apparent, and this kind of selection has the potential to lead to severe gender imbalance.  However, gender selection is illegal in the UK and CREATE does not support it.

A recent scientific advancement was the ‘3-person baby’ technique. This allows women with mitochondrial disease to receive mitochondrial donation from another woman.  The donor mitochondria are introduced into the embryo to replace the faulty mitochondria of the mother, meaning that the resulting baby harbours DNA from 3 separate people, though the amount of genetic material from the donor is miniscule. The law changed to allow this technique in February in the United Kingdom. Its proponents argue that mitochondrial DNA does not contain any characteristic-defining DNA, and that introducing donor mitochondria is likely only to reduce suffering. At the moment this technology is available only to carriers of mitochondrial disease, so in this sense, the ethical principle underlying the use of mitochondrial transfer is similar to that justifying the use of PGD.

The future of ‘designer babies’

Technology surrounding embryo alteration and selection is improving all the time, throwing up ethical and legal questions. Many people fear that the rapid scientific progression will lead to a ‘Gattaca-style’ world in which babies’ physical and personality traits are selected before birth. Gene-editing technology has increased in precision recently, and the development of the CRISPR-Cas9 gene-editing tool means that specific genes can be pinpointed and replaced. One major difference between CRISPR-Cas9 and other gene-editing tools is that CRISPR-Cas9 causes changes to the germline, so any changes are passed on to future generations, which is of great concern to many.

However, the laws surrounding this kind of science are extremely strict, and before any kind of selection on the basis of non-medical genetics could occur, the law would have to be changed considerably. At the moment, selection of embryos is only permitted on medical grounds and editing of the human genome is strictly prohibited.  Following the development of the CRISPR-Cas9 tool, scientists called for a halt on its development and use until the ethics and legalities behind the technology were fully established. Scientists themselves are therefore very aware of how important it is to tread carefully where human DNA is concerned.

Another factor which limits the use of gene technology is that the human genome is incredibly complex and it is not easy to find which genes are responsible for which traits. Scientists have been looking for the genetic origins of a variety of traits for years and have never been able to find them. This is partly because most physical and personality traits are coded for by multiple genes in different parts of the genome, and it is very difficult to pinpoint each of these many genes. Even if these genes were found and altered, it is unlikely that this would make much of a difference to humanity overall, as there are so many other factors involved in making a person who they are, such as epigenetics (the interactions between genes) and the environment. 

These legal and scientific obstacles combined mean that a world of ‘designer babies’ is far from becoming a reality. Although there is some embryo selection in place already, realistically this is strictly limited to specific medical cases, and no changes are made that could affect the germline.  For the time being therefore, this technology is used for the benefit of individuals rather than for the alteration of the human race.  


By Anna Byrne-Smith