non-Aboriginal Births Research Articles

557Outcomes of Indigenous multifetal and singleton pregnancies: complications, medical care, birth experience and infant health

Abstract Background Perinatal outcomes for singleton pregnancies are poorer, on average, for Aboriginal people than non-Aboriginal people, but little is known about Aboriginal multifetal pregnancies. Yet multifetal pregnancies and births are often more complicated and have poorer outcomes than singleton pregnancies. We describe the pregnancies, births and outcomes for Aboriginal twins born in Western Australia (WA) and New South Wales (NSW) with comparisons to Aboriginal singletons (WA and NSW) and non-Aboriginal births (NSW). Methods Whole-population birth and hospital records were linked for births during 2000-2013 (WA) and 2002-2008 (NSW). Descriptive statistics are reported for demographics, maternal health, pregnancy complications, births and infant outcomes. Results Pregnancy complications were more common among mothers of Aboriginal twins than Aboriginal singletons (e.g. 17% of mothers of WA twins had hypertension/pre-eclampsia/eclampsia vs 8% for singletons) but similar to mothers of NSW non-Aboriginal twins. Most Aboriginal twins were born in principal referral, women’s or large public hospitals. The hospitals were often far from the mother’s home (e.g. 31% of mothers of WA Aboriginal twins gave birth at hospitals located >3 hours by road from their home). Outcomes were worse for Aboriginal liveborn twins than Aboriginal singletons and non-Aboriginal twins (e.g. 58% of NSW Aboriginal twins were preterm versus 9% of Aboriginal singletons and 49% non-Aboriginal twins). Conclusions Mothers of Aboriginal twins faced significant challenges during the pregnancy, birth and the postnatal period in hospital. Key messages In addition to accessible specialist medical care, these mothers may need extra practical and psychosocial support throughout their journey.

Pregnancy and birth characteristics of Aboriginal twins in two Australian states: a data linkage study

IntroductionPerinatal outcomes for singleton pregnancies are poorer, on average, for Aboriginal people than non-Aboriginal people, but little is known about Aboriginal multifetal pregnancies. Yet multifetal pregnancies and births are often more complicated and have poorer outcomes than singleton pregnancies. We describe the pregnancies, births and perinatal outcomes for Aboriginal twins born in Western Australia (WA) and New South Wales (NSW) with comparisons to Aboriginal singletons in both states and to non-Aboriginal births in NSW.Materials and methodsWhole-population birth records and birth and death registrations were linked for all births during 2000–2013 (WA) and 2002–2008 (NSW). Hospital records and the WA Register of Developmental Anomalies - Cerebral Palsy were linked for all WA births and hospital records for a subset of NSW births. Descriptive statistics are reported for maternal and child demographics, maternal health, pregnancy complications, births and perinatal outcomes.ResultsThirty-four thousand one hundred twenty-seven WA Aboriginal, 32,352 NSW Aboriginal and 601,233 NSW non-Aboriginal births were included. Pregnancy complications were more common among mothers of Aboriginal twins than Aboriginal singletons (e.g. 17% of mothers of WA twins had hypertension/pre-eclampsia/eclampsia vs 8% of mothers of singletons) but similar to mothers of NSW non-Aboriginal twins. Most Aboriginal twins were born in a principal referral, women’s or large public hospital. The hospitals were often far from the mother’s home (e.g. 31% of mothers of WA Aboriginal twins gave birth at hospitals located more than 3 h by road from their home). Outcomes were worse for Aboriginal liveborn twins than Aboriginal singletons and non-Aboriginal twins (e.g. 58% of NSW Aboriginal twins were preterm compared to 9% of Aboriginal singletons and 49% non-Aboriginal twins).ConclusionsMothers of Aboriginal twins faced significant challenges during the pregnancy, birth and the postnatal period in hospital and, in addition to accessible specialist medical care, these mothers may need extra practical and psychosocial support throughout their journey.

Birth prevalence of congenital heart defects in Western Australia, 1990-2016.

To describe the birth prevalence and characteristics of congenital heart defects in a geographically defined Australian population. This descriptive, population-based study examined congenital heart defects in live births, stillbirths and pregnancy terminations ascertained by the Western Australian Register of Developmental Anomalies, 1990-2016. Birth prevalence (per 1000 births) was stratified by severity, known cause, maternal and birth characteristics, and primary diagnosis; and prevalence ratios were calculated for Aboriginal versus non-Aboriginal births. Temporal trends in prevalence, diagnosis age and infant mortality were examined. For births 1990-2010 (allowing 6 years for complete case ascertainment by 2016), 6419 cases were identified; prevalence was 11.5 per 1000 births (95% confidence interval (CI), 11.2-11.8). Severe defects were ascertained in 2.5 per 1000 births (95% CI 2.4-2.7). Most cases were liveborn (5842, 91.0%), and 28.9% had other birth defects. Prevalence was slightly higher in Aboriginal births (prevalence ratio 1.1; 95% CI 1.0-1.2); and the infant mortality rate more than doubled (13.4% vs. 5.8%, P< 0.001). Prenatal diagnosis increased over time but, in remote areas, was significantly lower for Aboriginal versus non-Aboriginal cases (3.1% vs. 9.3%; P= 0.008). A cause was identified in 920 cases (14.3%), more often for severe defects (347, 24.4%); 63% of known causes were rare diseases. Congenital heart defects associated with fetal alcohol spectrum disorder were much more common in Aboriginal births (prevalence ratio 82; 95% CI 28-239). Earlier detection of congenital heart defects and improved survival has occurred over time, although discrepancies between ethnic groups and regions warrant further investigation and strategic action.

Disparities in severe neonatal morbidity and mortality between Aboriginal and non-Aboriginal births in Western Australia: a decomposition analysis

BackgroundThe health disadvantages faced by Australian Aboriginal peoples are evidenced in early life, although few studies have focused on the reasons for population-level inequalities in more severe adverse outcomes. This...

Disparities between Aboriginal and non-Aboriginal perinatal mortality rates in Western Australia from 1980 to 2015.

Perinatal mortality rates are typically higher in Aboriginal than non-Aboriginal populations of Australia. This study aimed to examine the pattern of stillbirth and neonatal mortality rate disparities over time in Western Australia, including an evaluation of these disparities across gestational age groupings. All singleton births (≥20weeks gestation) in Western Australia between 1980 and 2015 were included. Linked data were obtained from core population health datasets of Western Australia. Stillbirth and neonatal mortality rates and percentage changes in the rates over time were calculated by Aboriginal status and gestational age categories. From 1980 to 2015, data were available for 930926 births (925715 livebirths, 5211 stillbirths and 2476 neonatal deaths). Over the study period, there was a substantial reduction in both the Aboriginal (19.6%) and non-Aboriginal (32.3%) stillbirth rates. These reductions were evident in most gestational age categories among non-Aboriginal births and in Aboriginal term births. Concomitantly, neonatal mortality rates decreased in all gestational age windows for both populations, ranging from 32.1% to 77.5%. The overall stillbirth and neonatal mortality rate differences between Aboriginal and non-Aboriginal birth decreased by 0.6 per 1000 births and 3.9 per 1000 livebirths, respectively, although the rate ratios (RR 2.51, 95% CI 2.14, 2.94) and (RR 2.94, 95% CI 2.24, 3.85), respectively reflect a persistent excess of Aboriginal perinatal mortality across the study period. Despite steady improvements in perinatal mortality rates in Western Australia over 3½ decades, the gap between Aboriginal and non-Aboriginal rates remains unchanged in relative terms. There is a continuing, pressing need to address modifiable risk factors for preventable early mortality in Aboriginal populations.

Prevalence of microcephaly in an Australian population-based birth defects register, 1980-2015.

To describe the prevalence and characteristics of microcephaly in a geographically defined Australian population. Descriptive epidemiological study of microcephaly cases ascertained by the Western Australian Register of Developmental Anomalies, 1980-2015, defining microcephaly as an occipito-frontal head circumference below the third percentile or more than two standard deviations below the mean sex- and age-appropriate distribution curve. Microcephaly prevalence (per 10 000 births) was calculated for cases with known and unknown causes, and by demographic characteristics. Temporal trends were analysed, and prevalence ratios (PRs) and 95% CIs calculated for Aboriginal and non-Aboriginal births. For births during 1980-2009 (ie, with at least 6 years' follow-up and therefore complete case ascertainment), 416 cases were identified, a prevalence of 5.5 per 10 000 births (95% CI, 4.95-6.02), or 1 in 1830 births. There was no significant temporal trend in prevalence (P = 0.23). Most cases were in live-born children (389, 93.5%), and other major birth defects were diagnosed in 335 of the affected children (80%). Prevalence was higher in Aboriginal births (PR, 4.5; 95% CI, 3.55-5.73). A cause of microcephaly was identified in 186 cases (45% of cases), and more often for Aboriginal (64 cases, 70%) than non-Aboriginal births (122 cases, 38%). The most frequent known cause of microcephaly in Aboriginal births was fetal alcohol spectrum disorder (FASD; 11 per 10 000 births); monogenic (0.68 per 10 000) and chromosomal conditions (0.59 per 10 000 births) were the most common causes in non-Aboriginal births. These data provide a baseline for prospective surveillance of microcephaly. We identified a high proportion of cases without known cause, highlighting the need for clinicians to carefully investigate all possibilities, including emerging infections. FASD is an important cause of microcephaly in the Aboriginal population.

Macrosomia, Perinatal and Infant Mortality in Cree Communities in Quebec, 1996-2010.

BackgroundCree births in Quebec are characterized by the highest reported prevalence of macrosomia (~35%) in the world. It is unclear whether Cree births are at greater elevated risk of perinatal and infant mortality than other First Nations relative to non-Aboriginal births in Quebec, and if macrosomia may be related.MethodsThis was a population-based retrospective birth cohort study using the linked birth-infant death database for singleton births to mothers from Cree (n = 5,340), other First Nations (n = 10,810) and non-Aboriginal (n = 229,960) communities in Quebec, 1996–2010. Community type was ascertained by residential postal code and municipality name. The primary outcomes were perinatal and infant mortality.ResultsMacrosomia (birth weight for gestational age >90th percentile) was substantially more frequent in Cree (38.0%) and other First Nations (21.9%) vs non-Aboriginal (9.4%) communities. Comparing Cree and other First Nations vs non-Aboriginal communities, perinatal mortality rates were 1.52 (95% confidence intervals 1.17, 1.98) and 1.34 (1.10, 1.64) times higher, and infant mortality rates 2.27 (1.71, 3.02) and 1.49 (1.16, 1.91) times higher, respectively. The risk elevations in perinatal and infant death in Cree communities attenuated after adjusting for maternal characteristics (age, education, marital status, parity), but became greater after further adjustment for birth weight (small, appropriate, or large for gestational age).ConclusionsCree communities had greater risk elevations in perinatal and infant mortality than other First Nations relative to non-Aboriginal communities in Quebec. High prevalence of macrosomia did not explain the elevated risk of perinatal and infant mortality in Cree communities.

Obstetric and Perinatal Morbidity in Northern Tasmanian Aboriginal Population: A Retrospective Cohort Study.

Aboriginal and Torres Strait Islander women are at increased risk of maternal morbidity and mortality as compared to non-Aboriginals. Similarly, aboriginal babies are at increased risk of low birth weight and infant mortality. To investigate the independent association of aboriginality with Tasmanian maternal and neonatal morbidity. A retrospective analysis of all the births (gestation more than 20 weeks) from June 2013 to May 2014 was conducted at the Launceston General Hospital, Tasmania. The study compared 66 Aboriginal (4.2% of the total births) to 1477 non-aboriginal births for maternal and neonatal morbidity. Comparisons were made using logistic regression. The outcome measures were maternal and neonatal morbidity. Significantly higher number of aboriginal women (49% vs 19%; OR 4.15 90%CI 2.52- 6.85) smoked and used illicit drugs (15% vs 2%; OR 9.24; 95%CI 4.28-19.96) than the non-aboriginal women (both p<0.001). Maternal morbidity was not significantly different between aboriginal compared to non-aboriginal women (OR 0.64; 95%CI 0.36-1.14; p=0.13; adjusted OR 1.00; 95%CI 0.52-1.93; p=0.99). Factors positively associated with maternal morbidity included: age (OR 1.28; 95%CI 1.13-1.46; p<0.01) and BMI (OR 1.50; 95%CI 1.33-1.70; p<0.01). The unadjusted OR of neonatal morbidity for aboriginality was 1.98 (95%CI 1.17-3.34; p=0.01) and adjusted was 1.45 (95%CI 0.77-2.72; p=0.25). Factors positively associated with neonatal morbidity included smoking (OR 2.24; 95%CI 1.59-3.14; p<0.01), illicit drug use 95%CI 1.49-(OR 3.26; 95%CI 1.49-7.13; p <0.01), hypertension (OR 2.49; 95%CI 1.61-3.84; p<0.01) and diabetes (OR 1.92; 95%CI 1.33-2.78; p<0.01). The composite Aboriginal maternal morbidity does not differ, however the increased rates of smoking and illicit drug use are largely responsible for neonatal morbidity. Along with strengthening strategies to decrease medical comorbidities in aboriginals, we recommend intensifying smoking and illicit drug cessation programs.

Disparities and Trends in Birth Outcomes, Perinatal and Infant Mortality in Aboriginal vs. Non-Aboriginal Populations: A Population-Based Study in Quebec, Canada 1996-2010.

BackgroundAboriginal populations are at substantially higher risks of adverse birth outcomes, perinatal and infant mortality than their non-Aboriginal counterparts even in developed countries including Australia, U.S. and Canada. There is a lack of data on recent trends in Canada.MethodsWe conducted a population-based retrospective cohort study (n = 254,410) using the linked vital events registry databases for singleton births in Quebec 1996–2010. Aboriginal (First Nations, Inuit) births were identified by mother tongue, place of residence and Indian Registration System membership. Outcomes included preterm birth, small-for-gestational-age, large-for-gestational-age, low birth weight, high birth weight, stillbirth, neonatal death, postneonatal death, perinatal death and infant death.ResultsPerinatal and infant mortality rates were 1.47 and 1.80 times higher in First Nations (10.1 and 7.3 per 1000, respectively), and 2.37 and 4.46 times higher in Inuit (16.3 and 18.1 per 1000, respectively) relative to non-Aboriginal (6.9 and 4.1 per 1000, respectively) births (all p<0.001). Compared to non-Aboriginal births, preterm birth rates were persistently (1.7–1.8 times) higher in Inuit, large-for-gestational-age birth rates were persistently (2.7–3.0 times) higher in First Nations births over the study period. Between 1996–2000 and 2006–2010, as compared to non-Aboriginal infants, the relative risk disparities increased for infant mortality (from 4.10 to 5.19 times) in Inuit, and for postneonatal mortality in Inuit (from 6.97 to 12.33 times) or First Nations (from 3.76 to 4.25 times) infants. Adjusting for maternal characteristics (age, marital status, parity, education and rural vs. urban residence) attenuated the risk differences, but significantly elevated risks remained in both Inuit and First Nations births for the risks of perinatal mortality (1.70 and 1.28 times, respectively), infant mortality (3.66 and 1.47 times, respectively) and postneonatal mortality (6.01 and 2.28 times, respectively) in Inuit and First Nations infants (all p<0.001).ConclusionsAboriginal vs. non-Aboriginal disparities in adverse birth outcomes, perinatal and infant mortality are persistent or worsening over the recent decade in Quebec, strongly suggesting the needs for interventions to improve perinatal and infant health in Aboriginal populations, and for monitoring the trends in other regions in Canada.

Diverging Trends in Gastroenteritis Hospitalizations During 2 Decades in Western Australian Aboriginal and Non-Aboriginal Children

Gastroenteritis is a major cause of pediatric morbidity. We describe temporal, spatial and seasonal trends in age-specific gastroenteritis hospitalizations among Aboriginal and non-Aboriginal Australian children during 2 decades, providing a baseline to evaluate the impact of a rotavirus vaccine program begun in 2007. We conducted a population-based, data linkage study of Aboriginal and non-Aboriginal births in Western Australia, 1983 to 2006, and analyzed gastroenteritis-coded hospitalizations before age 15 years in the cohort of 596,465 births. Hospitalization rates in Aboriginal and non-Aboriginal children and between geographical regions were compared between 1983 to 1994 and 1995 to 2006. Gastroenteritis rates were highest in children 6-11 months of age (Aboriginal: 259.3/1000/annum; non-Aboriginal: 22.7/1000/annum). Rates declined in Aboriginal children between 1983 to 1994 and 1995 to 2006, particularly in those 12-17 months of age (309/1000 to 179/1000). Rates in non-Aboriginal children<5 years increased 10-40%. The disparity for gastroenteritis rates between Aboriginal and non-Aboriginal children<5 years declined from being 15.4 times higher to 7.6 times higher in those aged 12-17 months and from 8.4 to 4.4 in those aged 2-4 years. Rates were highest in rural and remote regions, and diverging temporal trends were seen in different geographical regions. Seasonality varied between Aboriginal and non-Aboriginal children and climatic zones. This is the largest study of gastroenteritis hospitalization trends in children. We found diverging trends of gastroenteritis hospitalization rates in Aboriginal and non-Aboriginal children. Although rates have declined in Aboriginal children, disparity between Aboriginal and non-Aboriginal children continues. Our findings highlight the need to consider age, ethnicity, seasonality and climate when evaluating rotavirus vaccine programs.

Rates of stillbirth by gestational age and cause in Inuit and First Nations populations in Quebec

Inuit and First Nations populations have higher rates of stillbirth than non-Aboriginal populations in Canada do, but little is known about the timing and cause of stillbirth in Aboriginal populations. We compared gestational age- and cause-specific stillbirth rates in Inuit and First Nations populations with the rates in the non-Aboriginal population in Quebec. Data included singleton stillbirths and live births at 24 or more gestational weeks among Quebec residents from 1981 to 2009. We calculated odds ratios (ORs), rate differences and 95% confidence intervals (CIs) for the retrospective cohort of Inuit and First Nations births relative to non-Aboriginal births using fetuses at risk (i.e., ongoing pregnancies) as denominators and adjusting for maternal characteristics. The main outcomes were stillbirth by gestational age (24-27, 28-36, ≥ 37 wk) and cause of death. Rates of stillbirth per 1000 births were greater among Inuit (6.8) and First Nations (5.7) than among non-Aboriginal (3.6) residents. Relative to the non-Aboriginal population, the risk of stillbirth was greater at term (≥ 37 wk) than before term for both Inuit (OR 3.1, 95% CI 1.9 to 4.8) and First Nations (OR 2.6, 95% CI 2.1 to 3.3) populations. Causes most strongly associated with stillbirth were poor fetal growth, placental disorders and congenital anomalies among the Inuit, and hypertension and diabetes among the First Nations residents. Stillbirth rates in Aboriginal populations were particularly high at term gestation. Poor fetal growth, placental disorders and congenital anomalies were important causes of stillbirth among the Inuit, and diabetic and hypertensive complications were important causes in the First Nations population. Prevention may require improvements in pregnancy and obstetric care.

Alcohol‐use disorders during and within one year of pregnancy: a population‐based cohort study 1985–2006

To examine alcohol-use disorders in pregnant women and the extent of under-reporting. Population-based cohort study. Western Australia. Women with a birth recorded on the Western Australian Midwives Notification System (1985-2006). Mothers with an International Classification of Diseases 9/10 alcohol-related diagnosis, indicating heavy alcohol consumption, recorded on population-based health datasets (non-Aboriginal n=5,839; Aboriginal n=2,583) were identified through the Western Australian data-linkage system. This 'exposed' cohort was frequency matched (on maternal age, year of birth of offspring, Aboriginal status) with comparison mothers without an alcohol-related diagnosis (non-Aboriginal n=33,979; Aboriginal n=8,005). Trends in maternal alcohol diagnoses in relation to pregnancy for non-Aboriginal and Aboriginal women. The proportion of children diagnosed with fetal alcohol syndrome (FAS) who had a mother with an alcohol diagnosis recorded during pregnancy. The proportion of Aboriginal mothers in Western Australia with an alcohol diagnosis (23.1%) is ten times greater than for non-Aboriginal mothers (2.3%). There has been a six-fold increase in the percentage of non-Aboriginal births with a maternal alcohol diagnosis recorded during pregnancy and a 100-fold increase for Aboriginal births. Around 70% of the mothers of children diagnosed with FAS did not have an alcohol diagnosis recorded during pregnancy and 18% of the mothers had no record of an alcohol diagnosis. Maternal alcohol exposure during pregnancy is significantly under-ascertained. Given the severe risks to the fetus from heavy prenatal alcohol exposure, assessment and recording of alcohol use should be routinely undertaken in maternity and other health settings.

Can linked emergency department data help assess the out-of-hospital burden of acute lower respiratory infections? A population-based cohort study

BackgroundThere is a lack of data on the out-of-hospital burden of acute lower respiratory infections (ALRI) in developed countries. Administrative datasets from emergency departments (ED) may assist in addressing this.MethodsWe undertook a retrospective population-based study of ED presentations for respiratory-related reasons linked to birth data from 245,249 singleton live births in Western Australia. ED presentation rates <9 years of age were calculated for different diagnoses and predictors of ED presentation <5 years were assessed by multiple logistic regression.ResultsED data from metropolitan WA, representing 178,810 births were available for analysis. From 35,136 presentations, 18,582 (52.9%) had an International Classification of Diseases (ICD) code for ALRI and 434 had a symptom code directly relating to an ALRI ICD code. A further 9600 presentations had a non-specific diagnosis. From the combined 19,016 ALRI presentations, the highest rates were in non-Aboriginal children aged 6–11 months (81.1/1000 child-years) and Aboriginal children aged 1–5 months (314.8/1000). Croup and bronchiolitis accounted for the majority of ALRI ED presentations. Of Aboriginal births, 14.2% presented at least once to ED before age 5 years compared to 6.5% of non-Aboriginal births. Male sex and maternal age <20 years for Aboriginal children and 20–29 years for non-Aboriginal children were the strongest predictors of presentation to ED with ALRI.ConclusionsED data can give an insight into the out-of-hospital burden of ALRI. Presentation rates to ED for ALRI were high, but are minimum estimates due to current limitations of the ED datasets. Recommendations for improvement of these data are provided. Despite these limitations, ALRI, in particular bronchiolitis and croup are important causes of presentation to paediatric EDs.

Heavy prenatal alcohol exposure and increased risk of stillbirth

To investigate the association between heavy prenatal alcohol exposure and stillbirth. Data linkage cohort study. Western Australia (WA). The exposed cohort included mothers with an alcohol-related diagnosis (International Classification of Diseases, ninth/tenth revisions) recorded in health data sets and all their offspring born in WA (1983-2007). Mothers without an alcohol-related diagnosis and their offspring comprised the comparison cohort. Exposed and comparison mothers were identified through the WA Data Linkage System. Odds ratios for stillbirth at 20+ weeks of gestation were estimated by logistic regression, stratified by Aboriginal status. The proportion of stillbirths at 20+ weeks of gestation is presented per 1000 births, as well as adjusted odds ratios (aOR) and 95% confidence intervals (95% CI), and population-attributable fractions. Increased odds of stillbirth were observed for mothers with an alcohol-related diagnosis at any stage of their life for both non-Aboriginal (aOR 1.36; 95% CI 1.05-1.76) and Aboriginal (aOR 1.33; 95% CI 1.08-1.64) births. When an alcohol diagnosis was recorded during pregnancy, increased odds were observed for non-Aboriginal births (aOR 2.24; 95% CI 1.09-4.60), with the highest odds of Aboriginal stillbirth occurring when an alcohol diagnosis was recorded within 1 year postpregnancy (aOR 2.88; 95% CI 1.75-4.73). The population-attributable fractions indicate that 0.8% of non-Aboriginal and 7.9% of Aboriginal stillbirths are the result of heavy alcohol consumption. Prevention of heavy maternal alcohol use has the potential to reduce stillbirths. The lack of an association between exposure during pregnancy and Aboriginal stillbirth in this study needs further investigation.

Aboriginal teenage pregnancies compared with non‐Aboriginal in South Australia 1995–1999

To compare pregnancy characteristics and outcomes between Aboriginal and non-Aboriginal teenagers. DESIGN, SETTING AND POPULATION: A retrospective cohort study using the perinatal data collection for South Australian births in 1995-1999: 449 Aboriginal and 4,625 non-Aboriginal teenagers. Comparison of socio-demographic and clinical characteristics, using relative risks. Rates of pregnancy, smoking during pregnancy, induction, delivery method, preterm and small-for-gestational-age births and perinatal mortality Aboriginal teenagers have a pregnancy rate more than twice as high as non-Aboriginal, but a smaller proportion of pregnancies are terminated. They have pregnancies earlier, are more likely to be single, to smoke during pregnancy, to have few antenatal visits, to give birth in a country hospital and to have infections and anaemia. They have lower induction and analgesia rates, but a higher caesarean section rate. Their babies are more likely to be small-for-gestational-age and preterm, to have a congenital abnormality, to require special and intensive nursery care and stay longer in hospital. While their perinatal mortality rate has halved since a decade ago, their neonatal death rate is still twice that of non-Aboriginal births. Aboriginal teenagers need special attention. Support in particular is needed for Aboriginal health workers in preconceptional counselling and health promotion programs that build the capacity of the community, eg concerning proper nutrition during pregnancy, smoking cessation, breastfeeding, SIDS prevention, support for early and regular attendance for antenatal care in friendly and culturally appropriate environments. Outreach services and sexual health services for young Aboriginal people also need expansion.

The contribution of maternal smoking to preterm birth, small for gestational age and low birthweight among Aboriginal and non-Aboriginal births in South Australia.

To determine the contribution of maternal smoking to preterm birth (< 37 weeks' gestation), small for gestational age (SGA, birthweight < 10th percentile for gestational age) and low birthweight (< 2500 g) among Aboriginal and non-Aboriginal births in South Australia. Retrospective cohort analysis of population-based perinatal data. The State of South Australia, population 1.5 million. 36059 women (of whom 851 were Aboriginal women) who had singleton births in 1998-1999. Relative risks and population-attributable risks of preterm birth, SGA and low birthweight from smoking in the second half of pregnancy, by age and Aboriginality. Aboriginal women had a higher rate of smoking in pregnancy than non-Aboriginal women (57.8% v 24.0% at the first antenatal visit) and high rates for all age groups, while the rates decreased with age among non-Aboriginal women. Heavy smoking increased with age, and Aboriginal women were heavier smokers. Women who smoked had elevated relative risks of preterm birth (1.64), SGA (2.28) and low birthweight (2.52), and all these showed a dose-response relationship. Among Aboriginal (versus non-Aboriginal) births, population-attributable risks were significantly higher for SGA (48% v 21%, and 59% for births to Aboriginal teenagers), low birthweight (35% v 23%) and preterm birth (20% v 11%). Health promotion programs, with a focus on smoking cessation and reducing uptake of smoking, need to be implemented in an appropriate cultural context, especially among young Aboriginal women. Such a program is being developed in South Australia.