This study was approved by the Ethics Committee
of Maharaj Nakhon Ratchasima Hospital. The data
were collected from pregnant women who delivered at
Maharaj Nakhon Ratchasima Hospital from the 1st of
September to the 31st of December 2009, excluding
twin pregnancies, infants with transverse, oblique lie
and pregnant women not delivered in the 24 hours from
admission to the hospital.