Maternal, care provider, and institutional-level risk factors for early term elective repeat cesarean delivery: a population-based cohort study.

To identify maternal, care provider, and institutional-level risk factors for early term (37-38 weeks) elective repeat cesarean delivery in a population-based cohort. Retrospective cohort study of women in the British Columbia (BC) Perinatal Data Registry, BC, Canada, 2008-2011, with an elective repeat cesarean delivery at term. Absolute percent differences (risk differences) in early term delivery rates were calculated according to maternal characteristics, type of care provider, calendar time (day of the week, time of year), and annual institutional obstetrical volume. Of the 7,687 elective repeat cesareans at term in BC, 55 % occurred before 39 + 0 weeks. Early term delivery was significantly more common with multiple previous cesareans [8.2 percentage points (95 % CI 5.5, 10.9) for 2 previous cesareans, 11.3 (95 % CI 5.1, 17.4) for 3 or more previous cesareans], obesity [6.7 percentage points (95 % CI 1.6, 11.7)], and a hospital obstetrical volume <2,500 deliveries per year. Type of care provider and calendar time were not significant risk factors for early term delivery. Early term elective repeat cesarean was common across a wide range of maternal, care provider, and institutional characteristics, suggesting that most obstetrical care settings would benefit from quality-improvement programs to reduce elective repeat cesarean deliveries before 39 weeks. A better understanding of the risks and benefits of early term delivery among obese women and women with multiple previous cesareans is needed given the higher rates of early term delivery observed in these women.