BIRTH under water may sometimes compromise the safety of the newborn infant, argues Professor James Walker, of St James's University Hospital, Leeds. Water births, he says in the British Journal of Obstetrics and Gynaecology, are not 'natural': primitive tribes do not practise the technique and neither do any of the primates.

After birth a baby only has a limited amount of time to reach the surface and breath, he says. A difficult delivery could increase the risks to the child.