Prepartum and intrapartum caesarean section rates at Mater Mothers' Hospital Brisbane 1997-2005

To document the rise in prepartum and intrapartum caesarean section and the demographic and medical factors contributing to the rise. Data from 52 423 deliveries between January 1997 to May 2005 were analysed for yearly change in caesarean section rates and multiple demographic and medical factors. The prepartum caesarean section rate increased by 1.6% per year and the intrapartum caesarean section rate by 0.8% per year. There was no increase in the overall prevalence of obesity, short stature, advanced maternal age, medical complications or previous caesarean section. There were significant increases in nulliparity, private care, induction of labour and the use of electronic monitoring, but these were insufficient to explain the magnitude of the rise. The increase in prepartum and intrapartum caesarean section displayed was not fully explained by medical and demographic changes in the population.