Caesarean section is the delivery of the baby by a surgical incision through the abdominal wall and the wall of the uterus. It is usually performed by opening the lower part of the uterus - called lower uterine segment Caesarean section - using an incision that goes from side to side rather than one that passes from top-to-bottom of the uterus (called a classical Caesarean section) since this is thought to provide better healing and less chance of rupture of the uterus during subsequent pregnancy and labour. Caesarean section is performed for such conditions as placenta praevia (described in this section) mal presentation (also described in this section), prolapsed cord (where the umbilical cord is delivered through the cervix ahead of the baby. Since if the baby were delivered by vagina it would cut off its own blood supply, it is essential to deliver by Caesarean section) or any condition where there is signs of increasing foetal distress in a delayed labour. Fear of the delivery of a child who develops birth damage as a result of oxygen starvation during delivery, and subsequent litigation, have led to increased use of Caesarean section as a means of delivery in some places.