The health of Australia's mothers and babies

During the last two decades, all States and Territories have developed perinatal data systems that provide valuable information on maternal risk factors and complications and the outcomes of mothers and infants. This information, collected by midwives and medical practitioners, is increasingly being used for research and policy development and discussion about issues relating to pregnancy and childbirth. The 1992 report on Australian mothers and babies drew attention to births to teenage mothers, mothers born overseas and Australian Aboriginals and Torres Strait Islanders, and to factors associated with caesarean births.³

Teenage births. Births to teenage mothers in Australia, of just over 20 per 1000 in the early 1990s, were well below the peak of 55.5 per 1000 in 1971.⁴ However, these figures give an incomplete picture of teenage pregnancy because only South Australia and the Northern Territory have population-based data about induced abortions. Analysing trends in birthrates fails to indicate the total extent of teenage pregnancy. In 1992, 14 396 teenage mothers gave birth in Australia: 4115 were aged under 18 years (2503 were aged 17; 1133 were aged 16; 357 were aged 15; and 122 were under 15 years). The South Australian data showed that for every 100 births to teenage mothers, there were 82 induced abortions.⁵ Extrapolating from these data, the estimate of teenage pregnancies nationally in 1992 was in excess of 26 000. Based on these annual figures, about one in five teenagers will become pregnant at some stage between the ages of 15 and 19 years, and one in 10 will give birth.

Women born overseas. Of all the women who gave birth in Australia in 1992, more than one in five (22.7%) were born overseas, and 6.3% of all mothers were born in Asia. Of those born in Asia, 3605 women (1.4% of all births) were from Vietnam, 2660 (1%) from the Philippines, 1881 (0.7%) from China, 1365 (0.5%) from Malaysia, 1164 (0.5%) from India and 1046 (0.4%) from Hong Kong. Perinatal outcome did not seem to differ greatly from that of infants of Australian-born mothers,⁶ but further research is needed to determine the effects of maternal risk factors on outcomes such as birthweight and perinatal mortality.

The recent substantial increase in births to Asian-born mothers, notably Vietnamese and Chinese women, places extra demands on health services to ensure that their special needs are met, particularly in Sydney and Melbourne, where disproportionate numbers of people from non-English-speaking backgrounds live. These women often have vastly different cultural beliefs and practices associated with pregnancy and childbirth. Bicultural health workers are increasingly being recognised as having an important role in establishing support networks for these women, familiarising them with the Australian health system, and assisting them in overcoming language and attitudinal barriers.

Australian Aboriginals and Torres Strait Islanders. Many aspects of caring for overseas-born women are also pertinent to health services for Australian Aboriginals and Torres Strait Islanders. In 1991, 7027 Aboriginal and Torres Strait Islander women gave birth, and 7257 did so in 1992, accounting for 2.9% of all mothers in both years. Many of these women travel long distances from remote communities to hospitals in larger centres, and thus frequently give birth in an unfamiliar environment. In 1992, one in four births in this group were to teenage mothers and almost one in three of these teenagers had had at least one other child.

The average birthweight (3150 g) of babies born to Aboriginal Australians and Torres Strait Islanders was 206 g less than that of all Australian babies, and the proportion of babies that were of low birthweight (< 2500 g) was 12.9%, more than double the rate of 6.3% for all births.

Caesarean births. The seemingly inexorable rise in deliveries by caesarean section in Australia continues unabated, with a peak at 18.3% of total deliveries in 1992. South Australia (22.1%) and Queensland (20.9%) consistently have the highest caesarean rates and Tasmania (16.1%) usually the lowest. The caesarean rate of 22.4% for women with private health insurance was more than 40% higher than the rate of 15.8% for women without insurance (partly attributable to more older women in the insured group). Caesarean rates for women with insurance having their first baby increased with maternal age, from 21.9% at 25-29 years to 28.1% at 30-34 years, 37.4% at 35-39 years, and 47.4% at 40-44 years. High caesarean rates were also associated with multiple births (39.2% for twins and 85.3% for triplets, compared with 18% for singleton births), with breech presentation in singleton births (73.8%), and with very low birthweight babies (53.8% for singleton babies weighing 1000-1499 g).

Relatively simple measures, such as more detailed recording of the indications for caesarean section and obtaining an opinion from another obstetrician about whether operative intervention is indicated, have proved effective in reducing caesarean rates.⁷The Royal Australian College of Obstetricians and Gynaecologists should address the issue of high caesarean rates in Australia by requiring regular audits of hospitals and medical practitioners.

The quality and usefulness of information about perinatal health can be enhanced in several ways. Firstly, it should be recognised that analysis of trends in teenage pregnancy and the formulation of preventive strategies require data about induced abortions as well as data about births. Secondly, by linking registrations of perinatal and infant deaths to information for all births from the perinatal data systems in every State and Territory, the association between maternal risk factors and outcomes can be better evaluated.^8,9 Thirdly, while the patterns of risk factors, type of care and outcomes are remarkably consistent from year to year, shortening the interval between the year of birth and the publication of State and national reports is an important goal.

Paul A L Lancaster

Director, Australian Institute of Health and
Welfare National Perinatal Statistics Unit, University of Sydney, NSW

1. National Health and Medical Research Council. Report on maternal deaths in Australia 1988-90. Canberra: AGPS, 1993.
2. Australian Bureau of Statistics. Perinatal deaths, Australia 1993. Canberra: ABS, 1994. (Catalogue No. 3304.0.)
3. Lancaster P, Huang J, Pedisich E. Australia's mothers and babies 1992. Sydney: AIHW National Perinatal Statistics Unit, 1995.
4. Australian Bureau of Statistics. Births, Australia 1993. Canberra: ABS, 1994. (Catalogue No. 3301.0.)
5. Chan A, Scott J, McCaul K, Keane R. Pregnancy outcome in South Australia 1992. Adelaide: South Australian Health Commission, 1993.
6. Guevara V, Taylor L. The health of mothers born in non-English-speaking countries and their babies, NSW 1990-1993. New South Wales Public Health Bull 1995; 6 Suppl S2: 1-52.
7. Myers SA, Gleicher N. A successful program to lower cesarean section rates. N Engl J Med 1988; 319: 1511-1516.
8. Perinatal Data Collection Unit. The Consultative Council on Obstetric and Paediatric Mortality and Morbidity. Births in Victoria 1983-1992. Melbourne: Department of Health and Community Services, 1994.
9. Gee V. Perinatal statistics in Western Australia. Tenth annual report of the Western Australian Midwives Notification System, 1992. Perth: Health Department of Western Australia, 1993.