title: Pre-pregnancy predictors of hypertension in pregnancy among Aboriginal and Torres Strait Islander women in north Queensland, Australia; a prospective cohort study.
abstract: BACKGROUND
  Compared to other Australian women, Indigenous women are frequently at greater risk for hypertensive disorders of pregnancy. We examined pre-pregnancy factors that may predict hypertension in pregnancy in a cohort of Aboriginal and Torres Strait Islander women in north Queensland.
  
  
  METHODS
  Data on a cohort of 1009 Indigenous women of childbearing age (15-44 years) who participated in a 1998-2000 health screening program in north Queensland were combined with 1998-2008 Queensland hospitalisations data using probabilistic data linkage. Data on the women in the cohort who were hospitalised for birth (n = 220) were further combined with Queensland perinatal data which identified those diagnosed with hypertension in pregnancy.
  
  
  RESULTS
  Of 220 women who gave birth, 22 had hypertension in the pregnancy after their health check. The mean age of women with and without hypertension was similar (23.7 years and 23.9 years respectively) however Aboriginal women were more affected compared to Torres Strait Islanders. Pre-pregnancy adiposity and elevated blood pressure at the health screening program were predictors of a pregnancy affected by hypertension. After adjusting for age and ethnicity, each 1 cm increase in waist circumference showed a 4% increased risk for hypertension in pregnancy (PR 1.04; 95% CI; 1.02-1.06); each 1 point increase in BMI showed a 9% adjusted increase in risk (1.09; 1.04-1.14). For each 1 mmHg increase in baseline systolic blood pressure there was an age and ethnicity adjusted 6% increase in risk and each 1 mmHg increase in diastolic blood pressure showed a 7% increase in risk (1.06; 1.03-1.09 and 1.07; 1.03-1.11 respectively). Among those free of diabetes at baseline, the presence of the metabolic syndrome (International Diabetes Federation criteria) predicted over a three-fold increase in age-ethnicity-adjusted risk (3.5; 1.50-8.17).
  
  
  CONCLUSIONS
  Pre-pregnancy adiposity and features of the metabolic syndrome among these young Aboriginal and Torres Strait Islander women track strongly to increased risk of hypertension in pregnancy with associated risks to the health of babies.
authors: School of Health Sciences, Division of Health Sciences, University of South Australia, City East Campus North Terrace (P5-21), GPO Box 2471, Adelaide, SA 5001, Australia. Sandra.Campbell@postgrads.unisa.edu.au
authors: Sandra K
authors: SK
authors: Campbell
authors: John
authors: J
authors: Lynch
authors: Adrian
authors: A
authors: Esterman
authors: Robyn
authors: R
authors: McDermott
mesh_terms: D050154:Adiposity / Q000208:ethnology*; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D006973:Hypertension / Q000208:ethnology*; D016742:Preconception Care; D011237:Predictive Value of Tests; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000208:ethnology*; D011446:Prospective Studies; D011793:Queensland / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D055815:Young Adult; D000095283:Australian Aboriginal and Torres Strait Islander Peoples