Hypertensive disorders of pregnancy among women of migrant origin in Finland: A population-based study

Introduction Hypertensive disorders of pregnancy are a leading cause of maternal and perinatal mortality and morbidity worldwide. We studied the prevalence of hypertensive disorders of pregnancy among women of migrant origin in Finland. Material and Methods This study used data from the nationwide Medical Birth Register. Information on the most recent singleton birth of women who delivered between 2004 and 2014 (n = 382 233) was included. Women were classified into nine regional categories based on the country of origin. Women of Finnish origin were the reference group. Generalized linear models adjusted for maternal age, socioeconomic position, smoking in pregnancy, parity, pre-pregnancy body mass index, preexisting diabetes and delivery year were used to study the association between region/country of origin and hypertensive disorders of pregnancy. Results Among the study population, almost 8% were of migrant origin. The prevalence of hypertensive disorders of pregnancy varied from 1.3% (women of East Asian origin) to 4.2% (women of Sub-Saharan African origin), compared with 4.6% in the Finnish origin reference group. Compared with women of Finnish origin, the risk for any hypertensive disorders of pregnancy after adjustment for confounders was lower for women of migrant origin, with an exception for women of Sub-Saharan African origin. When analyzing gestational hypertension and preeclampsia outcomes separately, Sub-Saharan African origin women had a lower risk for gestational hypertension (risk ratio [RR] 0.41, 95% confidence interval [CI] 0.30-0.56) but a higher risk for preeclampsia (RR 1.77, 95% CI 1.44-2.17) than women of Finnish origin. Conclusions In general, women of migrant origin in Finland had a lower risk for any hypertensive disorders of pregnancy and gestational hypertension. The risk for preeclampsia was higher among women of Sub-Saharan African origin and may warrant special attention.