Scientists at Oxford University's department of paediatrics studied over 400 babies who were suffering from a severe form of bronchiolitis.

BBC: Gene key to baby chest infection

Professor John Wyatt, of the London's University College Hospital's department of paediatrics and child health, said one of the issues was that the debate was extremely "polarised" with some seeing it as a black or white issue.

BBC: NEWS | Health | Doctors grapple with abortion debate