Reduced prevalence of small-for-gestational-age and preterm birth for women of low socioeconomic position: a population-based cohort study comparing antenatal midwifery and physician models of care

Objective Our aim was to investigate if antenatal midwifery care was associated with lower odds of small-for-gestational-age (SGA) birth, preterm birth (PTB) or low birth weight (LBW) compared with general practitioner (GP) or obstetrician (OB) models of care for women of low socioeconomic position. Setting This population-level, retrospective cohort study used province-wide maternity, medical billing and demographic data from British Columbia, Canada. Participants Our study included 57？872 pregnant women, with low socioeconomic position, who: were residents of British Columbia, Canada, carried a singleton fetus, had low to moderate medical/obstetric risk, delivered between 2005 and 2012 and received medical insurance premium assistance. Primary and secondary outcome measures We report rates, adjusted ORs (aOR), and 95% CIs for the primary outcome, SGA birth (