Anne W. Read

Association between breast feeding and asthma in 6 year old children: findings of a prospective birth cohort study

Abstract Objectives: To investigate the association between the duration of exclusive breast feeding and the development of asthma related outcomes in children at age 6 years. Design: Prospective cohort study. Setting: Western Australia. Subjects: 2187 children ascertained through antenatal clinics at the major tertiary obstetric hospital in Perth and followed to age 6 years. Main outcome measures: Unconditional logistic regression to model the association between duration of exclusive breast feeding and outcomes related to asthma or atopy at 6 years of age, allowing for several important confounders: sex, gestational age, smoking in the household, and early childcare. Results: After adjustment for confounders, the introduction of milk other than breast milk before 4 months of age was a significant risk factor for all asthma and atopy related outcomes in children aged 6 years: asthma diagnosed by a doctor (odds ratio 1.25, 95% confidence interval 1.02 to 1.52); wheeze three or more times since 1 year of age (1.41, 1.14 to 1.76); wheeze in the past year (1.31, 1.05 to 1.64); sleep disturbance due to wheeze within the past year (1.42, 1.07 to 1.89); age when doctor diagnosed asthma (hazard ratio 1.22, 1.03 to 1.43); age at first wheeze (1.36, 1.17 to 1.59); and positive skin prick test reaction to at least one common aeroallergen (1.30, 1.04 to 1.61). Conclusion: A significant reduction in the risk of childhood asthma at age 6 years occurs if exclusive breast feeding is continued for at least the 4 months after birth. These findings are important for our understanding of the cause of childhood asthma and suggest that public health interventions to optimise breast feeding may help to reduce the community burden of childhood asthma and its associated traits. Key messages Asthma is the leading cause of admission to hospital in Australian children and its prevalence is increasing Whether breast feeding protects against asthma or atopy, or both, is controversial Asthma is a complex disease, and the relative risks between breast feeding and asthma or atopy are unlikely to be large; this suggests the need for investigation in a large prospective birth cohort with timely assessment of atopic outcomes and all relevant exposures Exclusive breast feeding for at least 4 months is associated with a significant reduction in the risk of asthma and atopy at age 6 years and with a significant delay in the age at onset of wheezing and asthma being diagnosed by a doctor Public health interventions to promote an increased duration of exclusive breast feeding may help to reduce the morbidity and prevalence of childhood asthma and atop

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.

Infant care practices in a metropolitan Aboriginal population

Objective: To describe sleeping position, room and bed‐sharing, tobacco smoke exposure and infant feeding for a sample of Australian Aboriginal infants from a metropolitan area.

Cesarean section and operative vaginal delivery in low-risk primiparous women, Western Australia.

OBJECTIVES. A major component of the increasing trend in cesarean sections in Western Australia is the rise in emergency cesarean sections in primiparous women. The aim of this study was to identify independent risk factors (particularly those known early in pregnancy) associated with operative delivery in low-risk primiparous women. METHODS. Retrospective multivariate logistic regression analyses of antenatal and perinatal data were conducted for all low-risk primiparous women entering labor spontaneously and giving birth in Western Australia in 1987 (n = 3641). RESULTS. Of the subjects, 58% had a spontaneous vaginal delivery, 8% had an emergency cesarean section, and 34% had an operative vaginal delivery. The significant independent risk factors for emergency cesarean section were older maternal age, shorter maternal height, heavier infant birthweight, and long labor. The risk factors for operative vaginal delivery were older maternal age, shorter maternal height, heavier infant birthweight, epidural an...

Genitourinary tract infections in pregnancy and low birth weight: case-control study in Australian aboriginal women.

OBJECTIVE--To investigate the association between genital and urinary tract infections in pregnant Aboriginal women and low birth weight. DESIGN--Retrospective case-control study controlling for potential confounding variables. SETTING--Western Australia from 1985 to 1987. SUBJECTS--All Aboriginal women (n = 269) who had given birth to singleton infants weighing 2250 g or less (cases), and 269 randomly selected Aboriginal women who had given birth to singleton infants weighing 3000 g or more (controls). MAIN OUTCOME MEASURES--Proportions of women in case and control groups who had had genital and urinary tract infections; odds ratios for low birth weight when genitourinary tract infection was present; population attributable fraction of low birth weight to genitourinary tract infection. RESULTS--At the time of delivery 51% of women in the case group (109/215) had genitourinary tract infections compared with 13% of controls (35/266). After controlling for potential confounding variables the odds ratio for giving birth to infants weighing 2250 g or less when genitourinary tract infection was present was 4.0 (95% confidence interval 2.3 to 7.0). The proportion of infants with low birth weight attributable to genitourinary tract infection in the whole population of Aboriginal women was 32% (95% confidence interval 17% to 49%). CONCLUSIONS--There was a strong association between low birth weight and the presence of genitourinary tract infections in Aboriginal women both during pregnancy and at the time of delivery. A community intervention trial of screening and treatment of genitourinary infections in this population is recommended.

Sudden infant death syndrome in Aboriginal and non-Aboriginal infants

This study, based on routinely recorded data, was designed to compare the epidemiology of sudden infant death syndrome (SIDS) in Aboriginal and non‐Aboriginal infants in Western Australia (WA). All cases of SIDS occurring in infants born in WA from 1980 to 1988 were included in the study. There were 66 Aboriginal (6.1 per 1000 live births) and 337 non‐Aboriginal (1.7 per 1000 live births) infants who died from SIDS. It was found that there was a significant linear increase in the Aboriginal SIDS rate over the study period while the non‐Aboriginal rate remained relatively constant. For non‐Aboriginal infants, there was an elevated risk of SIDS for young maternal age, single marital status and male gender but this was not found for Aboriginal infants. There was a significant difference in the age at death distribution for the two populations. Low birthweight and preterm birth were risk factors for both Aboriginal and non‐Aboriginal infants. There may be differences in the aetiology and/or classification of SIDS between the two populations.

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.

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.

Hospital admissions before the age of 2 years in Western Australia.

A linked data file of birth records and hospital admissions was used to investigate inpatient hospital morbidity before 2 years of age for all non-Aboriginal and Aboriginal children born in Western Australia in 1986. Of the non-Aboriginal children, 31.8% were admitted to hospital at least once before the age of 2 years, with an overall admission rate of 526/1000 live births; the corresponding figures for Aboriginal children were 68.7% and 2797. The mean number of days in hospital for each non-Aboriginal child admitted was 7.4, and 26.5 for Aboriginal children. Of the total cohort, 21% of non-Aboriginal and 20% of Aboriginal children were admitted only once, and 4% of non-Aboriginal and 36% of Aboriginal children were admitted at least three times; 23% of non-Aboriginal and 24% of Aboriginal children were admitted for only one major disease category, and 1% of non-Aboriginal and 16% of Aboriginal children were in at least four categories. The highest admission rates and highest percentages of the cohort admitted were for gastrointestinal and respiratory diseases and social admissions. These results illustrate the importance for both descriptive and analytical research of relating admissions to hospital for the total population to the individual child, and of using clinically relevant disease classifications.

A case‐control study of intrapartum stillbirths

Objective To determine antenatal and intrapartum risk factors for intrapartum stillbirths in a total population.