Grant: CIHR Fellowship

The rate of cesarean delivery (CD) in Canada has increased from 17.6% in 1995 to 27.9% in 2015. High rates of CD are potentially responsible for unnecessary utilization of health resources as well as maternal and neonatal harm. The reasons for the increase in CD rates are multifactorial and not well understood. Recent data suggests that CD rates below 20% are possible, safe, and compatible with optimal health outcomes for mothers and their newborns. For instance, Sweden has had a stable, relatively low CD rate for years (16.4% in 2003 and 17.4% in 2015), along with low rates of maternal and perinatal adverse outcomes. However, direct comparisons of CD rates between populations tends to be compromised by differences in obstetric profiles and risk factors for adverse perinatal outcomes. Furthermore, there is an implied presumption that any increase in CD rates represents an adverse change which needs to be remedied. The alternative perspective on this issue is that any increase in CD rates needs to be set against potential improvements in maternal, fetal and infant health. Increases in CD rates that occur concomitantly with declines in maternal, fetal and infant adverse outcomes may potentially justify higher CD rates. Therefore, this research aims to use retrospective cohort studies with data from Canada and Sweden to 1) identify subpopulations of women responsible for the variation in CD rates between Canada and Sweden, 2) contrast these populations using analyses that incorporate important between-country differences in risk factors for CD, such as maternal age, pre-pregnancy body-mass-index and weight gain in pregnancy, and 3) evaluate differences in CD rates in Canada and Sweden within the context of maternal, fetal and infant morbidity and mortality. These issues have yet to be addressed in the extant literature and hence represent critical knowledge gaps for women, clinicians, public health policy-makers, and related stakeholders.