Recorded pregnancy histories of the mothers of singletons and the mothers of twins: a longitudinal comparison.

A population-based record linkage case cohort of 239,995 births, to 119,214 women, born in Western Australia from 1980 to 2001 inclusive, was used to measure the recording of selected indicators of maternal health (current and prior) during pregnancy. We compared records of women with singleton pregnancies with that in twin pregnancies Mothers of first- and second-born singletons (n = 117,647) were compared with women with a first-born singleton followed by twins (n = 1,567). Binary indicators were used to calculate population prevalence of medical conditions, pregnancy complications and birth outcomes. Infant outcomes included stillbirth, low birthweight, preterm birth and birth defects. Women with twins were significantly older and taller, with similar rates of medical conditions and pregnancy complications during first singleton pregnancies compared with women with two consecutive singletons. However, during their second pregnancy, women with twins had significantly higher rates of essential hypertension, pre-eclampsia, threatened abortion, premature rupture of the membranes and ante partum hemorrhage with abruption than women with singletons. For both groups, maternal conditions in the first pregnancy were underreported in the second pregnancy, including diabetes, epilepsy, asthma, chronic renal dysfunction and essential hypertension. At the second birth, twins were 3 times more likely to be stillborn, 17 times more likely to be low birthweight and 4 times more likely to be delivered preterm compared with singletons. This research demonstrates the importance for epidemiologists and others, of having access to a complete maternal medical history for analyses of risks associated with maternal, infant and childhood morbidity.

Modern and traditional diets for Noongar infants.

AIM: Describe breast- and bottle-feeding patterns and the introduction of solid feeds and sugar containing drinks to the dietary intake of a cohort of urban Aboriginal infants in the first year of life. METHODS: Two hundred and seventy-four infants were recruited to a cohort study and information about infant nutrition was collected from their mothers during face to face interviews when the infants were aged 6-12 weeks, 7-8 months and 12 months old. RESULTS: 88.3% of mothers initiated breast-feeding, but only 43.8% of infants were exclusively breast-fed at 6-12 weeks. By 12 months of age 69.8% of babies had received fruit juice in their bottles, 59.8% received cordial. 64.5% of infants were given water in their bottles. The majority of infants had received 'fast foods' by 12 months of age with 56.2% had been given coca cola, 68% lemonade and 78% fried chips. CONCLUSIONS: This study highlights areas in which nutrition health promotion can be targeted to prevent common childhood health problems including promoting and supporting mothers to sustain breast-feeding and opportunities to reduce the sugar and fat intake among infants.

Bibbulung Gnarneep ('solid kid'): causal pathways to poor birth outcomes in an urban Aboriginal birth cohort.

AIM: To explore the causal pathways leading to poor birth outcomes among a cohort of Aboriginal infants. METHODS: A cross-sectional study was conducted. Data were collected via face-to-face interviews conducted 6-12 weeks post partum and links to the WA Midwives' Notification System. Two hundred and seventy-three Aboriginal infants and their families from Perth, Western Australia were recruited in the mid to late 1990s. RESULTS: Poor birth outcome was defined as low birth weight and/or preterm birth. Criteria for poor birth outcome were met by 12.3% of the cohort. A history of maternal hypertension, vaginal bleeding and consumption of excess spirits in pregnancy were independent predictors of poor birth outcome. Mother being raised on a mission, maternal education, smoking during pregnancy and being exposed to passive smoke during pregnancy were also important risk factors. CONCLUSIONS: Results indicate that maternal social exposures, maternal ill-health before the index pregnancy and maternal ill-health during the index pregnancy are all important contributors to poor birth outcomes for urban Aboriginal infants. While the causes of poor birth outcomes are complex, the current study highlights several areas where preventive measures may be useful.

Sudden infant death syndrome and unascertainable deaths: trends and disparities among Aboriginal and non-Aboriginal infants born in Western Australia from 1980 to 2001 inclusive.

AIM: To analyse patterns and trends in mortality from unknown causes (sudden infant death syndrome and unascertainable deaths) for all Aboriginal and non-Aboriginal infants born in Western Australia, 1980-2001. METHODS: Using total population linked data, we reviewed all post-mortem reports, including death scene investigations and final causes of death as ascertained by the coroner. Neonatal, post-neonatal and infant mortality rates attributed to unknown causes were calculated and the latter were analysed according to maternal age, geographical location, gestational age, sex and birthweight. Relative risks (95% confidence interval) for Aboriginal infants (compared with non-Aboriginal) were calculated. RESULTS: The proportion of deaths considered to be of unascertainable cause has significantly increased in recent years. In contrast to the non-Aboriginal population, there has been no significant decrease in deaths in the Aboriginal population and the overall relative risk for Aboriginal infants for the most recent years studied was 7.9 (95% confidence interval 5.1-12.2). The relative risk was significantly increased for most categories analysed. CONCLUSION: Reviewing post-mortem reports enabled identification of changes in the classification of deaths due to unknown causes. This provided a more accurate picture of the patterns and long-term trends of such deaths so that programmes can be developed to specifically target those groups most at risk. Adequately funded and evaluated education campaigns aimed at reducing the risk of sudden infant death syndrome among Aboriginal infants are required, as well as sustaining the current efforts that have been so successful for non-Aboriginal infants.

Patterns, trends, and increasing disparities in mortality for Aboriginal and non-Aboriginal infants born in Western Australia, 1980-2001: population database study.

BACKGROUND: Since there are known disparities between Aboriginal and non-Aboriginal populations in Australia, trends in infant mortality rates can be used to assess the effectiveness of programmes designed to improve the health of Aboriginal populations. We have examined mortality rates in these populations in Western Australia. METHODS: We used the most comprehensive and valid total population data available for an Australian state to determine all-cause and cause-specific mortality for Aboriginal and non-Aboriginal infants born in Western Australia from 1980 to 2001. FINDINGS: Overall, infant mortality rates fell in both populations, but less so in Aboriginal (from 25.0 in 1980-84 to 16.1 in 1998-2001) than in non-Aboriginal infants (from 8.4 in 1980-84 to 3.7 in 1998-2001) such that disparities between the two groups increased for all major causes of infant death. The relative risk for Aboriginal compared with non-Aboriginal infants rose from 3.0 (95% CI 2.5-3.6) to 4.4 (3.5-5.5), and there were significantly more potentially preventable deaths, such as those caused by infections (5.9 per 1000 livebirths vs 0.7 per 1000 livebirths, RR 8.5, 95% CI 7.1-10.2). Additionally, for Aboriginal infants, postneonatal mortality rates were higher than neonatal mortality rates (11.2 per 1000 livebirths vs 9.7 per 1000 livebirths), trend analyses showed that previous reductions in deaths due to preterm birth (4.3 per 1000 livebirths--1.4 per 1000 livebirths from 1980-97) were not sustained in the most recent years studied (3.5 per 1000 livebirths), and rates of sudden infant death syndrome did not fall significantly (4.9 per 1000 livebirths vs 4.7 per 1000 livebirths). INTERPRETATION: These increasing disparities between Aboriginal and non-Aboriginal infants, especially in remote areas, demand immediate action in partnership with Aboriginal communities, focusing on both access to primary health care and better living conditions. Implementation and assessment of policies to reduce the continuing social and economic disadvantage faced by Aboriginal families are vital.

Experience of respiratory and allergic illness in children attending childcare.

OBJECTIVES: To describe previous illness for children attending two types of formal childcare (130 family daycare homes and 11 child daycare centres). DESIGN: A questionnaire was completed by the parents of 846 children, which provided information about previous illness and associated factors. The questionnaire was conducted in Perth, Western Australia. RESULTS: Of all children, 39% had experienced otitis media, 11% glue ear and 26% allergies; 18% had been diagnosed with asthma; 10% had been admitted to hospital with respiratory illness, and 9% had experienced more than six respiratory conditions in the previous year. Attending centre daycare compared with family daycare was more likely to be associated with some of the previous illness outcomes (more than six respiratory illnesses in the past year, asthma, otitis media and glue ear) but, for all children, the major predisposing factors associated with these illnesses were a family history of atopy or bronchitis. CONCLUSIONS: Children with a history of respiratory illness or otitis media are more likely to be attending centre than family daycare, but family history of respiratory illness is an important risk factor for all children in childcare.

Population based ascertainment of twins and their siblings, born in Western Australia 1980 to 1992, through the construction and validation of a maternally linked database of siblings.

This paper describes the creation of a unique maternal identifier for use in the investigation of perinatal, postneonatal and child outcomes in relation to maternal characteristics. All Midwives' records of Western Australian (WA) births were routinely linked to registrations of births and deaths for infants born from 1980 to 1992 inclusive, then linked to WA hospital discharge data and to registries of birth defects and cerebral palsy to create a longitudinal health record for each infant. However, since each birth to a woman was recorded as a separate event, there was no way to identify siblings. Probabilistic record linkage, based on information about the mother, was used for this task. Logical inconsistencies within the data were used to test the validity of the linkages between birth records attributed to each mother. Information about the mother from other epidemiological studies and data abstracted from hospital case notes was also used to validate sibships. Linkage of the records of 310,255 births in WA during that period resulted in the formation of 181,133 sibships of one or more children. Pooling the results of all of the validation methods gave an error of 0.9%. Linkage identified 3678 sibships containing multiple births, and 305 sets of maternal twins. Ascertainment of twins and their siblings for an ongoing twin register, the WA Twin Child Health (WATCH) study, was a natural consequence of this process.