Lord Justice Balcombe ruled that those faced with such decisions should conduct a balancing exercise, the outcome of which depended on the individual factors of the case.
The judge allowed an appeal by a 16 year old mother against a High Court decision that face to face contact with her 15 month old son should be ended.
The mother is in care and the subject of a secure accommodation order. The court had been told there had been incidents in which the boy had been at risk because of his mother's inability to control herself.
But he said the mother, who had assaulted children's home staff where she was staying, been found in possession of drugs and said to have been involved in prostitution, had also made a suicide attempt. There was concern she could make further attempts to injure herself if prevented from seeing her son.
The judge said the question of contact between mother and son related to the upbringing of each of them and ion each case the Children Act 1989 required that their welfare should be the paramount consideration of the courts.
In facing what appeared to be the impossibility of giving paramount consideration to two parties, a balancing act had to be carried out.
Lord Justice Balcombe said: 'You start with an evenly balanced pair of scales. Of course, when you start to put into the scales the matters relevant to each child the result may come down in favour of the one rather than the other, but that is a balancing exercise which the court is well used to conducting in cases concerning children'.
The court ruled it could be positively beneficial for the mother to have contact with her son and, provided it was properly monitored, should not in the short term be detrimental for the boy. The judge said the situation would have to be reassessed when a suitable long term foster home was found for the boy.