Biopsychosocial factors influencing the occurrence and recurrence of preterm singleton births among Australian women: A prospective cohort study

Introduction: In Australia, 8.6% of all births are premature, and this figure has relativelyincreased by 10% in the past decade. A range of biological, psychological, and socialfactors have previously been identified as predictors of preterm birth using cross sectionaldata; however, this lacks ascertainment of a cause-and-effect relationship.This study harnessed the power of longitudinal cohort data by investigating pretermbirth among women prospectively followed for 19 years using a comprehensiveframework that examines biological, psychological, and social factors concurrently.

Methods: Data from 5,292 women (11,256 newborns) who reported singleton birthsbetween 1996 and 2015 in the Australian Longitudinal Study on Women's Health wereincluded.

Results: The prevalence of preterm birth was 8.5% for first-births and 5.9% for allbirths.The recurrent preterm birth rate was 9.5% . Risk factors for first preterm birthswere chronic hypertension (OR 2.34; 95% CI: 1.67-3.27), gestational hypertension (OR2.87; 95% CI: 2.22-3.72), gestational diabetes (OR 1.66; 95% CI: 1.14-2.41),menarche before 12 years (OR 1.36; 95% CI: 1.02-1.82) and history of miscarriage(OR 1.35; 95% CI: 1.01-1.79). Risk factors for all preterm births were a history ofpreterm birth (OR 2.33; 95% CI: 1.46-3.70), menarche before 12 years (OR 1.33; 95%CI: 1.00-1.77), not being partnered (OR 1.31; 95% CI: 1.02-1.69), chronic hypertension(OR 2.02; 95% CI: 1.45-2.82), gestational hypertension (OR 3.22; 95% CI: 2.43-4.25),gestational diabetes (OR 1.67; 95% CI: 1.16-2.41), and asthma (OR 1.40; 95% CI:1.14-1.72). Premature birth was less likely for second or later births (OR 0.44; 95% CI:0.36-0.55) compared to first births. Premature birth was also less likely for women whocompleted a university degree compared to women with a high school certificate (OR0.73; 95% CI: 0.57-0.94).

Conclusion: Further development of multi-sectoral policies for chronic diseaseprevention and reducing social inequalities is required to prevent preterm birth inAustralia.