Variation in and factors associated with timing of low risk, pre-labour repeat caesarean sections in NSW, 2008-2011

Abstract

In April 2007, the New South Wales (NSW) Ministry of Health released an evidence-based policy directive requiring that ‘where there are no compelling medical indications, elective or pre-labour caesarean section does not occur prior to 39 completed week’s gestation’. This study describes variation in and factors associated with hospital rates of early (37-38 weeks gestation), low risk pre-labour repeat caesarean section at term. Linked birth and hospital data for low-risk, pre-labour repeat caesarean sections in NSW in 2008-2011 were analysed using multi-level regression modelling. Rates were adjusted for casemix and hospital factors. In 2008-2011, there were 15,163 pre-labour repeat caesarean sections among low risk women in NSW. Overall, 34.7% of low risk pre-labour repeat caesarean sections occurred before 39 weeks gestation. Casemix and hospital factor adjusted NSW public hospital rates of early (37-38 weeks gestation), low risk, pre-labour repeat caesarean section at term varied widely (16.3%-67.5%). Smoking, private health care, assisted reproductive technology, higher parity, a non-caesarean uterine scar and delivering in a hospital with CPAP facilities were associated with higher odds of early delivery. Hospitals with higher rates of low risk deliveries and higher propensity for vaginal birth after caesarean rates had lower odds of early delivery. The findings suggest poor uptake of the policy for pre-labour caesarean from 39 weeks. Large between-hospital variation persisted following adjustment, suggesting that non-medical factors are related to timing of low risk, pre-labour caesarean section. Further strategies are needed to enhance adherence to evidence-based policy.