Loretta Weatherall

A cohort of Indigenous Australian women and their children through pregnancy and beyond: the Gomeroi gaaynggal study.

Indigenous Australians have high rates of chronic diseases, the causes of which are complex and include social and environmental determinants. Early experiences in utero may also predispose to later-life disease development. The Gomeroi gaaynggal study was established to explore intrauterine origins of renal disease, diabetes and growth in order to inform the development of health programmes for Indigenous Australian women and children. Pregnant women are recruited from antenatal clinics in Tamworth, Newcastle and Walgett, New South Wales, Australia, by Indigenous research assistants. Measures are collected at three time points in pregnancy and from women and their children at up to eight time points in the childs first 5 years. Measures of fetal renal development and function include ultrasound and biochemical biomarkers. Dietary intake, infant feeding and anthropometric measurements are collected. Standardized procedures and validated tools are used where available. Since 2010 the study has recruited over 230 women, and retained 66 postpartum. Recruitment is ongoing, and Gomeroi gaaynggal is currently the largest Indigenous pregnancy-through-early-childhood cohort internationally. Baseline median gestational age was 39.1 weeks (31.5-43.2, n=110), median birth weight was 3180 g (910-5430 g, n=110). Over one third (39.3%) of infants were admitted to special care or neonatal nursery. Nearly half of mothers (47.5%) reported tobacco smoking during pregnancy. Results of the study will contribute to knowledge about origins of chronic disease in Indigenous Australians and nutrition and growth of women and their offspring during pregnancy and postpartum. Study strengths include employment and capacity-building of Indigenous staff and the complementary ArtsHealth programme.

Effects of Maternal Inflammation and Exposure to Cigarette Smoke on Birth Weight and Delivery of Preterm Babies in a Cohort of Indigenous Australian Women

Sudden infant death syndrome (SIDS), neonatal deaths, and deaths from infection are higher among Indigenous Australians. This study aimed to determine the effects of inflammatory responses and exposure to cigarette smoke, two important factors associated with sudden death in infancy, on preterm birth, and birth weight in a cohort of Indigenous mothers. Indigenous Australian women (n = 131) were recruited as part of a longitudinal study while attending antenatal care clinics during pregnancy; blood samples were collected up to three times in pregnancy. Serum cotinine, indicating exposure to cigarette smoke, was detected in 50.4% of mothers. Compared with non-Indigenous women, the cohort had 10 times the prevalence of antibodies to Helicobacter pylori (33 vs. 3%). Levels of immunoglobulin G, antibodies to H. pylori, and C-reactive protein (CRP) were all inversely correlated with gestational age (P < 0.05). CRP levels were positively associated with maternal body mass index (BMI; ρ = 0.449, P = 0.001). The effects of cigarette smoke (cotinine) and inflammation (CRP) were assessed in relation to risk factors for SIDS: gestational age at delivery and birth weight. Serum cotinine levels were negatively associated with birth weight (ρ = −0.37, P < 0.001), this correlation held true for both male (ρ = −0.39, P = 0.002) and female (ρ = −0.30, P = 0.017) infants. Cotinine was negatively associated with gestational age at delivery (ρ = −0.199, P = 0.023). When assessed by fetal sex, this was significant only for males (ρ = −0.327, P = 0.011). CRP was negatively associated with gestational age at delivery for female infants (ρ = −0.46, P < 0.001). In contrast, maternal BMI was significantly correlated with birth weight. These data highlight the importance of putting programs in place to reduce cigarette smoke exposure in pregnancy and to treat women with chronic infections such as H. pylori to improve pregnancy outcomes and decrease risk factors for sudden death in infancy.

Dietary intakes and anthropometric measures of Indigenous Australian women and their infants in the Gomeroi gaaynggal cohort.

Indigenous Australians continue to experience disparities in chronic diseases, many of which have nutrition-related trajectories. Optimal nutrition throughout the lifespan is protective for a number of adverse health outcomes, however little is known about current dietary intakes and related anthropometric outcomes of Indigenous women and their infants. Research is required to identify nutrition issues to target for health promotion activities. The Gomeroi gaaynggal programme is an ongoing, prospective cohort of pregnant Indigenous Australian women and their children. A cross-sectional examination of postnatal dietary intakes and anthropometric outcomes of mothers and children are reported. To date, 73 mother-child dyads have participated postpartum. Breastfeeding initiation was 85.9% and median (interquartile range) duration of any breastfeeding was 1.4 (0.5-4.0) months. Infants were introduced to solid foods at 5.0 months (4.0-6.0) and cows milk at 12.0 (10.0-13.0) months. At 12 months postpartum, 66.7% of women were overweight or obese, 63.7% at 2 years. Compared with recommendations, reported median maternal nutrient intakes from 24-h recall were low in fibre, folate, iodine, calcium, potassium and vitamin D and high in proportions of energy from total and saturated fat. Limitations of this study include a small sample size and incomplete data for the cohort at each time point. Preliminary data from this ongoing cohort of Indigenous Australian women and children suggest that women may need support to optimize nutrient intakes and to attain a healthy body weight for themselves and their children.

The Gomeroi Gaaynggal Cohort: A Preliminary Study of the Maternal Determinants of Pregnancy Outcomes in Indigenous Australian Women

The life expectancy of Indigenous Australians is amongst the lowest of any population group within developed nations and chronic diseases collectively account for over 80% of the gap in life expectancy between Indigenous and non-Indigenous Australians. The Gomeroi gaaynggal cohort is a prospective, longitudinal maternal-infant cohort established to examine the origins of chronic disease in Indigenous Australians. This study aimed to determine the major antenatal factors associated with adverse birth outcomes (preterm delivery, low birth weight) and other pregnancyrelated complications (gestational diabetes and hypertensive disorders of pregnancy) in Indigenous Australian women. Pregnant women who identified as Indigenous Australians or pregnant non-Indigenous women giving birth to an Indigenous infant were eligible to participate in the cohort (n=227). Physical measurements and biological sample collection (including blood and urine) were undertaken up to 3 times in pregnancy. Median weight and BMI of the cohort was 80.7 kg and 30.3 kg/m2 at enrolment (median 23 weeks gestation). 43% reported smoking cigarettes during pregnancy. Of the 158 women in whom pregnancy outcomes were known, 43% had an uncomplicated pregnancy, 13.9% delivered preterm, 14.6% delivered a small-for-gestational age infant, 10% developed a hypertensive disorder of pregnancy, and 6.3% developed gestational diabetes. In addition, many women showed evidence of underlying renal dysfunction (proteinuria or albuminuria). The ratio of male to female offspring in this cohort was 1.38. Eightyseven percent of preterm infants were male, as were 83.3% of babies from women with gestational hypertension. This skewed sex distribution was far higher than for those who had a healthy pregnancy outcome (59%). This study demonstrates that key factors including maternal obesity, exposure to cigarette smoke and underlying renal impairment, influence pregnancy outcome. Preliminary findings from this study also suggest that more male babies are born early and from complicated pregnancies in this Indigenous cohort.

Post‐traumatic stress disorder symptoms in pregnant Australian Indigenous women residing in rural and remote New South Wales: A cross‐sectional descriptive study

Pregnancy can be a stressful time for many women. There is ample evidence of numerous physical and mental health inequities for Indigenous Australians. For those Indigenous women who are pregnant, it is established that there is a higher incidence of poor physical perinatal outcomes when compared with non‐Indigenous Australians. However, little evidence exists that examines stressful events and post‐traumatic stress disorder (PTSD) symptoms in pregnant women who are members of this community.

Urinary angiotensinogen excretion in Australian Indigenous and non-Indigenous pregnant women

The intrarenal renin-angiotensin system (iRAS) is implicated in the pathogenesis of hypertension, chronic kidney disease and diabetic nephropathy. Urinary angiotensinogen (uAGT) levels reflect the activity of the iRAS and are altered in women with preeclampsia. Since Indigenous Australians suffer high rates and early onset of renal disease, we hypothesised that Indigenous Australian pregnant women, like non-Indigenous women with pregnancy complications, would have altered uAGT levels. The excretion of RAS proteins was measured in non-Indigenous and Indigenous Australian women with uncomplicated or complicated pregnancies (preeclampsia, diabetes/gestational diabetes, proteinuria/albuminuria, hypertension, small/large for gestational age, preterm birth), and in non-pregnant non-Indigenous women. Non-Indigenous pregnant women with uncomplicated pregnancies, had higher uAGT/creatinine levels than non-Indigenous non-pregnant women (P < 0.01), and levels increased as pregnancy progressed (P < 0.001). In non-Indigenous pregnant women with pregnancy complications, uAGT/creatinine was suppressed in the third trimester (P < 0.01). In Indigenous pregnant women with uncomplicated pregnancies, there was no change in uAGT/creatinine with gestational age and uAGT/creatinine was lower in the 2nd and 3rd trimesters than in non-Indigenous pregnant women with uncomplicated pregnancies (P < 0.03, P < 0.007, respectively). The uAGT/creatinine ratios of Indigenous women with uncomplicated or complicated pregnancies were the same. A decrease in uAGT/creatinine with advancing gestational age was associated with increased urinary albumin/creatinine, as is seen in preeclampsia, but it was not specific for this disorder. The reduced uAGT/creatinine in Indigenous pregnant women may reflect subclinical renal dysfunction which limits the ability of the kidney to maintain sodium balance and could indicate an increased risk of pregnancy complications and/or future renal disease.

Characterizing gestational weight gain in a cohort of Indigenous Australian women

OBJECTIVE to determine the adequacy of gestational weight gain for a cohort of Indigenous Australian women and investigate whether it is associated with pre-pregnancy body mass index. DESIGN analysis of observational data collected from a longitudinal cohort study that follows Indigenous Australian women through pregnancy. SETTING women recruited through antenatal clinics in regional and remote towns in NSW, Australia to the Gomeroi gaaynggal program. PARTICIPANTS 110 pregnant women who either identified as being an Indigenous Australian or as carrying an Indigenous child. MEASUREMENTS AND FINDINGS measurements included weight and height, self-reported pre-pregnancy weight and smoking status, parity and health conditions that may contribute to gestational weight gain, such as hypertensive or diabetic disorders. Compared to the 2009 Institute of Medicine recommendations for gestational weight gain and based on prepregnancy body mass index, the rate of adequate gestational weight gain in this cohort was very low (15%). 32% of women had inadequate weight gain and 54% had excessive weight gain. The highest rate of excessive gestational weight gain was found in overweight women (74%), with rates of 48% and 50% found in healthy and obese (all classes) categories, respectively. Parity (coefficient 4.5, p<0.01) and hypertension (coefficient 4.8, p = 0.04) were found to be significantly associated with gestational weight gain in mixed model linear regression. CONCLUSIONS few women gained adequate gestational weight gain in this study. Culturally acceptable ways of addressing this issue are needed for this group of women, as inadequate and excessive rates of gestational weight gain have health implications for women and their offspring. IMPLICATIONS FOR PRACTICE a systematic approach to addressing gestational weight gain within antenatal care is required, including asking about diet and exercise, for all women identifying as Indigenous Australian.

Assessment of Fetal Kidney Growth and Birth Weight in an Indigenous Australian Cohort

Introduction: Indigenous Australians experience higher rates of renal disease and hypertension than non-Indigenous Australians. Low birth weight is recognized as a contributing factor in chronic disease and has been shown to increase the risk of renal failure in adulthood. A smaller kidney volume with fewer nephrons places an individual at risk of hypertension and renal failure. Indigenous Australians have fewer nephrons than non-Indigenous Australians. In this study, intrauterine fetal and kidney growth were evaluated in 174 Indigenous Australian babies throughout gestation in order to record and evaluate fetal growth and kidney size, within a population that is at high risk for chronic illness. Methods: Pregnant women that identified as Indigenous, or non-Indigenous women that were pregnant with a partner who identified as an Indigenous Australian were eligible to participate. Maternal history, smoking status, blood and urine samples and fetal ultrasounds were collected throughout pregnancy. Fetal kidney measurements were collected using ultrasound. Statistical analysis was performed using the Stata 14.1 software package. Results: 15.2% of babies were born prematurely. 44% of the mothers reported smoking in pregnancy. The median birth weight of this cohort was 3,240 g. Male fetuses had higher kidney to body weight ratios than female fetuses (P = 0.02). The birth weights of term neonates whose mothers smoked during pregnancy were lower (327 g, P < 0.001) than the birth weights of term babies from non-smoking mothers. The kidney volumes of babies whose mothers smoked were also smaller (P = 0.02), but were in proportion to body weight. Conclusion: In this cohort of Indigenous women smoking was associated with both increased number of preterm births and with a reduction in birth weights, even of term infants. Since kidney volume is a surrogate measure of nephron number and nephrogenesis is complete at birth, babies whose mothers smoked during pregnancy must have fewer nephrons than those from non-smoking mothers. Previous studies have shown that glomerular filtration rate is not related to birth weight, thus infants with smaller kidney volumes are hyperfiltering from birth and therefore are likely to be more susceptible to early onset renal disease in later life.

Reference intervals for non-fasting CVD lipids and inflammation markers in pregnant Indigenous Australian women

Indigenous Australians experience high rates of cardiovascular disease (CVD). The origins of CVD may commence during pregnancy, yet few serum reference values for CVD biomarkers exist specific to the pregnancy period. The Gomeroi gaaynggal research project is a program that undertakes research and provides some health services to pregnant Indigenous women. Three hundred and ninety-nine non-fasting samples provided by the study participants (206 pregnancies and 175 women) have been used to construct reference intervals for CVD biomarkers during this critical time. A pragmatic design was used, in that women were not excluded for the presence of chronic or acute health states. Percentile bands for non-linear relationships were constructed according to the methods of Wright and Royston (2008), using the xriml package in StataIC 13.1. Serum cholesterol, triglycerides, cystatin-C and alkaline phosphatase increased as gestational age progressed, with little change seen in high-sensitivity C-Reactive Protein and γ glutamyl transferase. Values provided in the reference intervals are consistent with findings from other research projects. These reference intervals will form a basis with which future CVD biomarkers for pregnant Indigenous Australian women can be compared.

Relationships in Indigenous Health Practice

Improving health outcomes for Indigenous people of Australia has become a key priority for health services and organisations since the launch of the Close the Gap campaign in 2006. In an effort to reduce the early origins of chronic disease, researchers from the University of Newcastle commenced a study in 2007 to understand health issues that affected pregnancy outcomes for Aboriginal women.