A prospective study of gestation and birthweight in Aboriginal pregnancies in far north Queensland

Abstract

This study aimed to determine the cause(s) of the increased incidence of low birthweight birth in Aboriginal pregnancies. The study prospectively examined a cohort of Aboriginal women presenting for antenatal care before 20 weeks gestation (ultrasound proven) and a reference cohort of Caucasian women in four remote North Queensland communities served by the Far North Regional Obstetric and Gynaecological Service (FROGS) and the antenatal clinic at Cairns Base Hospital. Women with no known medical factors affecting fetal growth or gestation were recruited. Of the 102 Aboriginal and 101 Caucasian women recruited, 96 Aboriginal and 96 Caucasian women completed the study, providing groups of sufficient size to allow statistical assessment at 80% power and 95% significance. Outcomes measured were gestation at delivery, planned or spontaneous birth, neonatal anthropometric measurements and Dubowitz score. The phenotypic and demographic characteristics of the women, their pregnancies, and their babies were also compared to understand the major associations with low birthweight birth in the Aboriginal women. Apart from Aboriginal ethnicity, excessive alcohol use in pregnancy, low maternal body mass index (BMI), and low maternal age had significant negative correlations with birthweight, and excessive tobacco use in pregnancy and high maternal gravidity showed strong similar trends. Culturally appropriate programs need to be funded and developed to reduce the incidence of low birthweight Aboriginal birth, rather than medical programs primarily aimed at the reduction of the incidence of preterm labour.