Caesarean rates have soared as high as 57 per cent in some WA hospitals, as women having babies get older and have more medical issues.
The latest breakdown of maternity figures shows that one in five women who gave birth in 2011 were 35 or older, compared with less than 5 per cent of mothers that age 30 years ago.
The WA Health Department's Mothers and Babies report reflects a continuing shift in demographics of women having babies - with more likely to have a caesarean, be aged over 34 and have pre-existing medical conditions and complications in pregnancy. The rate of elective caesareans has trebled in the past 30 years, and half of all births now involve caesareans or the use of instruments such as forceps.
While the rate of caesareans at the State's main public maternity hospital, King Edward Memorial, has remained unchanged at 35 per cent in recent years, rates have risen at several private hospitals, with St John of God Hospital Murdoch recording the highest at 57.1 per cent in 2011 - up from 55.8 per cent in 2010.
Doctors' groups, including the Australian Medical Association, have defended the use of caesareans, saying the high rate reflects more women at some hospitals being at higher risk because of factors such as age and weight.
But a survey of 165 GPs, published in Medical Forum, showed half of female doctors and one-third of male doctors did not believe the caesarean rate was appropriately linked to medical complications.
Childbirth educator Pip Wynn Owen said though obstetricians argued women were older and more obese and risk- averse, she believed the fear of litigation played a role.