Why Are Cascade Birth Interventions Rising?

Abstract

The increasing use of birth interventions has prompted global policy and research focus. This study attempts to enhance our understanding of why this increase is occurring. Using a population-based dataset of over 1.3 million births in New South Wales, Australia (2004–2018), we identified a growing prevalence of a “cascade” of interventions, including labour induction, epidural analgesia and either instrumental or caesarean delivery. We found that this rise has been concentrated in low-risk nulliparous women, a group that had no clinical indication or preference for intervention at labour onset. To understand this trend, we investigated the roles of maternal characteristics, hospital selection and institutional practice styles. Here, we show considerable variation in the use of a cascade of interventions at the hospital level, and that these hospital-level practice styles—and not compositional changes in the characteristics of women giving birth, nor their hospital choices—account for much of the increase in the use of cascade interventions over time. These findings highlight the importance of institutional factors in shaping clinical care, and suggest new directions for policy and research.