Differences in obstetric care among nulliparous First Nations and non-First Nations women in British Columbia, Canada.

Background: Canada's Aboriginal population faces significantly higher rates of stillbirth and neonatal and postnatal death than those seen in the general population. The objective of this study was to compare indicators of obstetric care quality and use of obstetric interventions between First Nations and non-First Nations mothers in British Columbia, Canada.

Methods: We linked obstetrical medical records with the First Nations Client File for all nulliparous women who delivered single infants in British Columbia from 1999 to 2011. Using logistic regression models, we examined differences in the proportion of women who received services aligned with best practice guidelines, as well as the overall use of obstetric interventions among First Nations mothers compared with the general population, controlling for geographic barriers (distance to hospital) and other relevant confounders.

Results: During the study period, 215,993 single births occurred in nulliparous women in British Columbia, 9152 of which were to members of our First Nations cohort. First Nations mothers were less likely to have early ultrasonography (adjusted risk difference = 10.2 fewer women per 100 deliveries [95% confidence interval {CI} -11.3 to -9.3]), to have at least 4 antenatal care visits (3.6 fewer women per 100 deliveries [95% CI -4.6 to -2.6]), and to undergo labour induction after prolonged (> 24 hours) prelabour rupture of membranes (-5.9 [95% CI -11.8 to 0.1]) or at post-dates gestation (-10.6 [95% CI -13.8 to -7.5]). Obstetric interventions including epidural, labour induction, instrumental delivery and cesarean delivery were used less often in First Nations mothers.

Interpretation: We identified differences in the obstetric care received by First Nations mothers compared with the general population. Such differences warrant further investigation, given increases in perinatal mortality that are consistently shown and that may be a downstream consequence of differences in care.