Cohort Profile: The Australian Aboriginal Birth Cohort (ABC) study

Indigenous Australians fare worse than other Australians on almost every measure of physical and mental health. Compared with non-Indigenous Australians, Indigenous people are more likely to have chronic disease such as obesity, diabetes, kidney disease, heart disease and circulatory problems, occurring at an earlier age, leading to premature mortality and influencing the lower life expectancies in Indigenous people being on average 10 years less than those of non-Indigenous people. Babies born to Indigenous women weigh on average almost 200 g less than those born to non-Indigenous women and are twice as likely to be low birthweight (LBW) (< 2500 g). In 1987, the Indigenous LBW rate (13%) in the Northern Territory (NT) was approximately double that of nonIndigenous births. Casual observation suggested that there were high numbers of fetal growth-restricted babies (FGR) delivered to Indigenous women, but difficulties in obtaining reliable gestational ages (GA) and conducting long-term follow-up meant the prevalence and outcomes of these Indigenous FGR babies were unknown. These factors led to the commencement of a prospective Aboriginal Birth Cohort study (ABC) to study the antecedents, prevalence and 10-year outcomes of FGR. Subsequent reports in the late 1980s, linking LBW/FGR to chronic adult diseases, led to the study being extended to a life course study. The study’s aim is to investigate the hypothesis that the high rates of chronic non-communicable diseases seen in this population were the result of processes that began in utero and continued after birth (Developmental Origins of Health and Disease hypothesis).