Saturday, 1 October 2016

3 Parent Babies: A Brave New World?

The world's first baby has been born using the '3 parent' technique! A team led by John Zhang helped a baby boy, now five months old, be the first to be born using the new technique that incorporates DNA from three people.

The first baby born with this technique was born in Mexico to parents who had previously suffered four miscarriages, as well as having two children that later died. All of these were caused by a genetic mutation in the mother's mitochondria.

As part of my university 'Bioethics' module last year, we covered this controversial topic. There are many ethical and moral implications to consider when discussing 3-parent babies. For this blog post, I'm going to cover some of the main ethical arguments. 

Before this, let's explore exactly what this technique entails. The term '3-parent babies' itself sounds daunting and like a science fiction film title, but it doesn't truly explain how the technique works. Another term to use is 'Mitochondrial Replacement Therapy' (or MRT). This is essentially a form of IVF in which the baby's mitochondrial DNA comes from a third party. During reproduction, DNA in the mother's mitochondria is passed on to the child. However, if women have mitochondrial diseases this is also passed on. 

Source: The Telegraph
This is where MRT comes in. MRT transfers healthy mitochondrial DNA from a third party (the 'third parent') into the mother's egg, through one of two processes. Once this occurs, the now healthy egg can be fertilised, and pregnancy can continue as normal. This mean that the child born will not experience the mitochondrial disease that would have otherwise been passed down from the mother. This is used in cases when the mother carries genetic mitochondrial diseases, or when other IVF techniques don't work. 

Some argue that this procedure is unethical, citing that approval of this technique is the start of a slippery slope towards designer babies. Personally I disagree - this technique is highly regulated, and has only been approved after extensive public debate and consultation. Also, our views on what is acceptable do change over time, and sometimes this can be for the better! For example, when the first 'test tube' baby was born in the 1970s, many were horrified by the procedure. Now this practice is commonplace. Professor John Harris, bioethicist, philosopher, author (and lecturer at my university), provided my favourite quote on this argument - that the extremity of a slippery slope depends only on our "choice of footwear". In other words, tight regulations and management ('a sensible pair of shoes') can ensure we do not slide down the slippery slope. 

Another ethical argument against 3-parent babies is that the risks and consequences are potentially unknown. The procedure is relatively new and has not extensively been tested in humans. As a result, some argued that something unforeseen could go wrong - and as the technique works on mitochondrial DNA, this would then be passed on to future generations. To combat this, Dr John Appleby suggested two conditions that should be in place; that the technique must be applied to only male children, and the child born must be informed. Using the technique only on male children would ensure any problems were not passed on (as the problem would lie in the mitochondrial DNA, which as I explained above is only passed on to new generations through the mother). My own defence to that argument would be that at some point all procedures are new and perceived as risky. The first organ transplant could have gone horribly wrong and killed those involved, but now is a successful procedure that saves lives. I would also argue that there are already so many risks to natural conception (STDs, random mutations etc), so why should we deny those with mitochondrial diseases their right to have children?  

John Zhang with the baby born using this technique. Source: New Hope Fertility Center
There are clearly many ethical implications to approval of this technique and they all need thorough consideration. The technique is legal here in the UK, as of October last year, but it is prohibited in the US, China and many other countries. 

What do you think of this new technique? Will this become the norm? Or do you think it's unethical and be banned? I'd love to know your thoughts in the comments below!

If you're interested to find out more, click here to read what the New Scientist has to say!


  1. I think it's fantastic. As you say it's an important technique for those affected with mitochondrial disease (a friend of mine works in research on these). I feel it's no different than selecting embryos without defect through IVF...

    1. I agree! Over time I'm sure it will be viewed in the same way. Thanks for your comment!

  2. This is interesting! is this a mix of surrogacy and IVF?

    1. Thanks for your comment. You're right in that this technique is related to IVF, as the eggs are fertilised and then implanted back into the mother. However, the mother then carries the fertilised egg throughout pregnancy, so it is unlike surrogacy. Hope that explains it a little more clearly!