Introduction: The prevalence of hypertensive disorders of pregnancy (HDP) as related to social determinants has not been previously described in Métis populations. Social context is important to guide interventions. In collaboration with the Métis Nation of Alberta, we evaluated the prevalence of HDP along socioeconomic (SES) gradients among Métis and non-Métis women in Alberta.
Methods: We conducted a population-based retrospective cohort study of singleton live births in Alberta between 2006-2016. A Métis cohort was identified from the Métis Nation of Alberta Identification Registry. The Alberta Perinatal Health Program provided perinatal variables. We used area-level Material and Social Deprivation components (MAT and SOC, respectively) from the Pampalon Index (an SES measure) derived from census data (2006), and linked to the postal code at delivery. HDP included chronic hypertension (CH), gestational hypertension (GH), preeclampsia, and preeclampsia superimposed on chronic hypertension (PES). We estimated concentration indexes (CIdx) with 95% confidence intervals (95%CI) to assess HDP inequalities across the MAT and SOC gradients. The CIdx indicates the proportion of cases accumulating by SES (it ranges from-1 to 1). A negative value indicates that the health outcome is concentrated in individuals of lower SES.
Results: A total of 7,910 Métis and 471,522 non-Métis births were evaluated. Prevalence of HDP in Métis and non-Métis were: CH: 0.5% and 0.3%; GH: 3.8% and 4%; preeclampsia: 1.3% and 1.1%; PES: 0.13% and 0.08%. Preeclampsia showed a negative CIdx of -0.05 (95%CI: -0.06, -0.03) for the MAT; and -0.03 for the SOC (95%CI: -0.05, -0.01) with no statistical difference between Métis and non-Métis populations (p-value > 0.05). Equal distributions of the remaining HDP across the SOC and MAT gradients were observed.
Conclusion: The prevalence of HDP was similar in Métis and non-Métis groups. Inequalities in preeclampsia towards the lower socioeconomic strata equally impacted the two groups analyzed.
Kelsey Bradburn– Director of Child and Family Services, Métis Nation of Alberta
Radha Chari– Professor, Department of Obstetrics & Gynecology. Division of Maternal-Fetal Medicine. University of Alberta
Ashton James– Senior Manager, Metis Nation of Alberta
Omolara Sanni– Postdoctoral Fellow, University of Alberta
Maria Ospina– Assistant Professor, University of Alberta