Outcomes for maternity trends have posted mix results across the board, according to new statistics released by the Australian Institute of Health and Welfare (AIHW).

The National Core Maternity Indicators report includes data collected between 2004 and 2009 across 10 key indicators, including rates of caesarean section, induction of labour, birth weight and rates of premature birth.

The report will be used as a baseline for measuring the effects of changes to maternity services across the country following the introduction of the 2012-15 National Maternity Services Plan in 2010.

"Some good news is that we have seen a higher proportion of women (80%) attending antenatal care during the first trimester, and a drop in the proportion of babies born weighing less than 2,750 grams at or after 40 weeks," said Professor Elizabeth Sullivan from the AIHW's National Perinatal Epidemiology and Statistics Unit.

"The proportion of babies born weighing less than 2,750 grams at or after 40 weeks  fell from 2.1% to 1.8% between 2004 and 2009 and was recorded in most settings.

"This is important, as it indicates that very few exceptionally small babies are being missed during antenatal screening for poor fetal growth."

Falls were also recorded in rates of episiotomy (a surgical cut into the woman's perineum) among women having their first baby and giving birth vaginally.

Between 2004 and 2009, rates of episiotomy dropped from 16.2% to 15.1% for women giving birth without instruments.

"Rates of smoking in pregnancy in Australia also dropped-from 16.7% to 14.5% between 2004 and 2009,' Professor Sullivan said.

"Although smoking rates dropped overall, significant differences among sociodemographic groups continue, with 36% of women living in Very remote areas reporting smoking in pregnancy compared with 13% in Major cities."

Among Indigenous women, about 51% reported smoking during pregnancy in 2004-2009.

"While we have seen positive improvements in a number of indicators, there are some areas for possible further attention," Professor Sullivan said.

"For example induction, caesarean section and instrumental vaginal birth rates increased over the period among most groups of women, while normal vaginal birth rates decreased proportionately.

"The proportion of babies with a low Apgar score has increased. Apgar scores are a measure of a baby's adaptation to the environment immediately after birth. The proportion of births with scores of less than 7 at 5 minutes rose from 0.9% to 1.1% between 2004 and 2009."

The full report can be found here