Professor Fergal Malone:

I was making my comments today in the context of foetal health and foetal abnormalities, because that is what we deal with at the Rotunda Hospital and in the maternity hospitals. As I pointed out in my paper, viability based on gestational age is just one aspect of viability. One could have a baby with severe growth restriction at 25 weeks who is 300 g and has no prospect of survival, yet one could have a 23-week foetus who is 600 g and has a prospect of survival. One could have a 25-week foetus with a very severe heart defect that has no prospect of survival if that foetus was born, yet a 23-week foetus that is completely healthy might have a chance of survival. To focus our definition of viability on some arbitrary gestational age week is just one piece of the equation. It is not possible to define viability in the total context of health. That is why one needs all the other pieces of information. The doctor together with the patient are the best placed to make that decision.