Prolonged pregnancy is associated with increased perinatal
morbidity and mortality1
. The risk increases from the
expected date of confinement (40 weeks of gestation) such
that placental insufficiency and postmaturity (greater than
42 weeks of gestation) are associated with an exponential
increase in the risk of perinatal death2
. Delivery beyond
42 weeks is associated with a fourfold increase in death
in utero, as well as a threefold increase in neonatal death
compared with delivery at term3
. In addition to mortality,
there is an increased risk of meconium aspiration syndrome,
neonatal seizures and long term handicap4
. In
1995, at the John Radcliffe Hospital, 1.1% of neonates
who were delivered after their estimated date of delivery
(EDD) experienced a serious adverse outcome (perinatal
death, birth asphyxia or meconium aspiration).