Putting a premature baby clinging to life in an oxygen box on a ventilator if her condition gets worse would not be in her best interests, the High Court has been told.
A paediatrician known as Dr H said 17- month- old Charlotte Wyatt's condition had improved since the court ruled in October that she should not receive any " aggressive" treatment, even if necessary to prolong her life.
But, Dr H said, she could not envisage a situation where such treatment would be the right course of action.
Back in October doctors won the legal right not to resuscitate Charlotte after arguing that she was braindamaged and "had no feelings other than continuing pain".
Charlotte weighed just 1lb and measured only five inches when she was born three months premature at St Mary's Hospital, Portsmouth, in October 2003, and has serious brain, lung and kidney damage.
Now the High Court, sitting in Cardiff, is due to hear evidence from experts saying she can now see, hear, smile and enjoy being cuddled.
Asked about putting Charlotte on ventilation, Dr H said: "I feel that it wouldn't be in her best interests; with the severity of her chronic lung disease, an acute respiratory infection is what would be fatal to her. To ventilate would only postpone it."
Charlotte's condition had improved since the New Year, she said.
"Her general condition improved, she was more settled, spending more time awake but not in distress, and not requiring as much sedation.
" She does make facial movements but I have never seen her smile, and I have held her, and talked to her and engaged with her but I've never seen her smile.
"She kicks her legs but she kicks her legs because she can't do anything else I feel, not because she is experiencing any emotion." David Wolfe, representing Charlotte's parents Darren and Debbie Wyatt, who are originally from Birmingham, put to her that it was "quite a dramatic change, isn't it, from the situation described unanimously by the medical profession in the autumn ?"
Dr H replied: "Yes. Really the only factor is that she is no longer in distress all the time and needing sedation."
But she said Charlotte " remains a baby with a number of chronic medical problems". Her brain had not grown since October, the court was told.
Peter Jackson, representing Portsmouth Hospitals NHS Trust, said: "It would be a complete distortion of this very difficult and anxious situation to see that those who in this instance do not believe that further aggressive treatment is in Charlotte's best interests somehow lack commitment to her. This is not a case about who cares more for Charlotte."
Darren Wyatt, aged 33, and Debbie, aged 23, who now live in Buckland, Portsmouth, sat at the back of the court while the evidence was heard.
Giving evidence via a video-link, another medical expert, known as Dr A, said it was "truly remarkable" that Charlotte had not succumbed to a respiratory infection.
The case continues.