WA is still Australia's caesarean capital with rates edging up as more women give birth in private hospitals compared with expectant mothers in other States.
An Australian Institute of Health and Welfare report on maternity trends found the national caesarean rate reached 32.3 per cent in 2011, with WA recording the highest rate of 33.9 per cent.
The figures were even higher in the State's first-time mothers, with 35.2 per cent having a surgical birth. It mirrors a trend of more WA women giving birth in private rather than public hospitals, with a rate of 40.9 per cent compared with the national average of 29 per cent, and a shift towards older motherhood.
Nationally, the average age of women having a baby is 28.3 years, while the proportion of teenage mothers has hit a low of 3.7 per cent.
AIHW spokeswoman Elizabeth Sullivan said caesarean rates rose as mothers got older.
"In 2011, caesarean section rates ranged from 18 per cent in teenage mothers to 49 per cent for mothers aged 40 and over," Professor Sullivan said.
Perth midwife and childbirth educator Pip Wynn Owen blamed some doctors and hospitals for promoting caesareans "as the norm".
"Many women are not getting to antenatal classes and are relying on their doctor for advice about giving birth, and even those who go to classes at private hospitals are not having their fears about a normal birth addressed," she said.
"So many women end up going along with a caesarean out of fear."
But Australian Medical Association WA vice-president Michael Gannon said though caesarean rates were higher in private hospitals, there was a range of contributing factors, particularly the fact that more women over the age of 35 were first-time mothers.
"We're seeing more older mothers and many are having smaller families, perhaps only one or two children, so they are less likely to want to go through a difficult labour," Dr Gannon said.
"In addition, more mothers are obese, have underlying medical problems or have conceived through IVF, and these increase the risk of complications such as diabetes and high blood pressure."