About 1 woman in 8 will need to have an instrumental delivery,
using either forceps or a ventouse suction cup to help to deliver
the baby's head. The commonest reasons for this are because there
are worries about the baby's heart rate or because it is taking a
long time for the baby to be pushed out (more common where an
epidural has been used for pain relief).
The aim is to mimic a natural birth with the minimum risk to mum
and baby. Sometimes it is safest to conduct these deliveries in the
obstetric theatre rather than in a delivery room. Often, the doctor
will need to perform an episiotomy in order to deliver the baby's
head if the baby is born using forceps or ventouse. You can
read more about instrumental delivery here.