Poster Presentation ESA-SRB Conference 2015

Maternal Obesity negatively impacts on fetal kidney development, maternal health and birth outcomes in an Indigenous Australian cohort (#316)

Kirsty G Pringle 1 2 , Eugenie R Lumbers 1 2 , Loretta Weatherall 3 4 , Clare Collins 5 , Roger Smith 2 , Kym Rae 3 4
  1. School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, New South Wales, Australia
  2. Mothers and Babies Research Centre, Hunter Medical Research Institute, New Lambton, New South Wales, Australia
  3. Gomeroi gaaynggal Centre, The University of Newcastle, Tamworth, New South Wales, Australia
  4. University of Newcastle Department of Rural Health, The University of Newcastle, Tamworth, New South Wales, Australia
  5. Priority Research Centre in Physical Activity and Nutrition , The University of Newcastle, Callaghan, New South Wales, Australia

Background: Chronic disease in Indigenous populations around the globe is prolific. There is a worldwide epidemic of obesity, a leading cause of chronic disease. The impact of obesity on pregnancy outcome is poorly understood as are the effects of maternal obesity on fetal organ development.

Methods: We studied a cohort of Indigenous pregnant women.  Maternal height, weight, BMI, and %body fat were measured as well as fetal size and fetal kidney volumes; the latter using ultrasound. Maternal health and birth outcomes were recorded.

Results: The median maternal weight and BMI of the cohort was 85.34kg (range: 45-148kg) and 30.74kg/m2 (15-52 kg/m2), and %body fat was 43.65% (17-63%). Maternal BMI was positively associated with birth weight (rho=0.32; p=0.005) but not with length of gestation. Both maternal BMI and %body fat were negatively associated with the infant’s combined kidney volume/ fetal weight (rho=-0.357, p=0.016 and rho=-0.406, p=0.014). 6.2% of the cohort developed gestational diabetes (GDM) and delivered earlier (p=0.002). These babies had a median birthweight centile that was significantly greater than that of babies whose mothers did not have GDM (p=0.031). GDM women had higher urinary protein/creatinine and albumin/creatinine (p=0.047 and p=0.024). There was no effect of maternal GDM on fetal kidney size.

Kidney volume is a surrogate measure of nephron number. The inverse correlation between kidney size and measures of maternal obesity implies that these babies are at risk of developing chronic renal disease. The mechanisms responsible for this association between kidney size and maternal obesity are unknown but the data highlight the need to reduce obesity in this population.