Report on Maternal Deaths in Australia 1994-1996
Highlights
The 1994-96 Report on Maternal Deaths in Australia is the eleventh in a series of triennial reports on maternal deaths dating back to 1964. This is an important series of reports that act as a sentinel for obstetric care and safe motherhood experience. The report is based on maternal mortality data across all States and Territories combined, and the AIHW and NHMRC recognise that these data are of variable quality. In an effort to improve ascertainment of maternal deaths, this particular report is based upon three data sources: States and Territories Confidential Death Enquiries, National Hospital Morbidity Database and the AIHW National Mortality Database. Nevertheless, in some cases maternal mortality data may be incomplete. Proper interpretation of these data and valid comparison with maternal mortality data from previous periods are therefore not possible in these circumstances. Improved standardisation of these data will be the aim in future reports.
There were 102 deaths reported to the Advisory Committee (Appendix 1), of which 100 deaths (46 direct, 20 indirect and 34 incidental) satisfied the definition of maternal deaths during pregnancy and the puerperium. This represented an increase of 19.0% in the number of deaths compared with the 1991-93 triennium. Of the 100 deaths, 46 were directly related to pregnancy. This represents an increase from the 27 deaths recorded in the previous triennium and reverses the trend of declining direct maternal deaths seen over the previous 15 years (54, 42, 32, 37, 27, 46). The reason for this increase is not clear and requires further investigation. The leading principal causes of direct maternal deaths remained pulmonary embolism (8), amniotic fluid embolism (8) and pre-eclampsia (7).
The Committee views with concern the increase in the number of maternal deaths, especially the number of direct deaths, the category of deaths resulting from obstetric complications of the pregnant state. The data are difficult to interpret as one-off rises or declines in the number of deaths are not conclusive; and it cannot be determined if the results indicate the beginning of a new trend or are just a normal statistical fluctuation of a very rare event, a maternal death. Both the 1991-93 and 1994-96 triennial figures may be aberrant and their significance will not be clear until the 1997-1999 and probably 2000-2002 figures are available. Therefore, it is critical that there be close monitoring of maternal deaths in the future to determine if there is a real increase and that all maternal deaths be investigated and scrutinised to determine if there are any modifiable or preventable factors.
Improved ascertainment has contributed to the increase in the total number of maternal deaths and partially explains the rise in direct deaths, as does the changing risk profile of women becoming pregnant. Many women are delaying childbirth, while an increasing number of women with complex medical problems are also having children. However, the contribution of other factors to maternal mortality, such as different models of delivery of obstetric care and the organisation of that care, requires further investigation.
The number of indirect deaths was similar to that reported in the last triennium (20 in 1994-96; 21 in 1991-93). The overall maternal mortality ratio was 13.0 per 100,000 confinements and was the highest reported since 1984. The maternal mortality ratios for direct and indirect deaths were 6.0 and 2.6 per 100,000 confinements respectively. These figures compare favourably with those of 6.1 and 6.1 per 100,000 confinements for direct and indirect deaths respectively, published in the Report on Confidential Enquiries into Maternal Deaths in the United Kingdom for the triennium 1994-96. In Australia in the 1994-96 triennium, the incidental maternal mortality ratio was 4.4 per 100,000 confinements, a ratio that has not fallen over the past seven triennia. However, the number of direct deaths has risen during the 1994-1996 triennium to once again outnumber incidental deaths. The maternal mortality ratio for direct deaths over the 1994-1996 triennium is the highest it has been since 1981.
It is important to note that the risk of maternal death during pregnancy and the puerperium remains small, being 1 in 7,675 confinements in the 1994-96 triennium. Improved general health status and reproductive patterns, together with access to appropriate general and specialised health care has greatly reduced the incidence of maternal mortality in the last century. The incidence of preventable deaths related to avoidable patient and medical factors is now very low. However, the Committee views with concern the increase in the proportion of direct maternal deaths in which avoidable factors were considered to be possibly or certainly present, from 7 (26%) of 27 deaths in 1991-93 to 22 (48%) of the 46 deaths in 1994-96 where avoidability was considered. These data are variable in quality, and it is hoped in future reports assessment of maternal deaths will be standardised. The Committee has produced a standardised maternal death reporting form to be used in future reporting of deaths which should facilitate this objective and minimise the risk of under-reporting the details of avoidability. The adoption of this form by State and Territory Maternal Mortality Committees for the 1997-99 report will support systematic consideration and documentation of avoidable factors for all maternal deaths and enhance expert clinical surveillance.
However, despite overall general improvements, it is important to note that life-threatening complications still occur, often unpredictably. Seeking to avoid loss of women's lives in childbearing, and minimising damage to their health, remain issues of critical importance for obstetric and midwifery practice in Australia. Against this background, the higher maternal mortality rate among Indigenous childbearing women should be of continuing concern to the Australian community, and demands attention as a priority from all relevant agencies.
It is hoped that this report will assist in the development of improved practice in obstetric care and provide information to obstetric care practitioners to improve the quality and safety of health care during pregnancy and the puerperium. The scope of national examination of the health of childbearing women should now be extended to include morbidity associated with pregnancy and childbirth.
Professor William Walters
Chairperson
Advisory Committee on Maternal Mortality and Morbidity