Serious preeclampsia among different immigrant groups

Objective — Research conducted outside Canada suggests that preeclampsia (PET) may be more common among certain ethnic groups. A limitation to prior studies is that they did not distinguish between immigrant and non-immigrant women; they also included women with mild PET arising near term, the clinical importance of which is debatable. The researchers created the term "serious PET" to describe a diagnosis of severe PET, eclampsia, or any degree of PET with concomitant preterm delivery, fetal death, or maternal hospitalization of seven days or more, and evaluated its risk in association with world region of origin among recent immigrants to Ontario.

Methods — Using the federal Landed Immigrant Data System database (LIDS), the researchers completed a population-based study of 118 849 women who immigrated to Ontario between 1985 and 2000. The LIDS was linked to the Canadian Institute for Health Information's Discharge Abstracts Database, thereby capturing all hospitalizations with subsequent delivery in Ontario between April 1, 2002, and March 31, 2009. Rates for serious PET were determined according to maternal world region of birth, and odds ratios were adjusted for maternal age, number of live births, multifetal pregnancy, diabetes mellitus status, level of formal education, place of residence, neighbourhood income quintile, duration of residence in Canada, and fiscal year of delivery.

Results — Immigrant women from the Caribbean (6.8 per 1000; OR 3.34; 95% CI 2.25 to 4.96), Sub-Saharan Africa (6.8 per 1000; OR 3.14; 95% CI 2.04 to 4.83) and Hispanic America (5.9 per 1000; OR 3.11; 95% CI 1.97 to 4.88) were at highest risk of serious PET relative to immigrant women from industrialized nations. The ORs were either unchanged or higher when restricted to women without a prior live birth.

Conclusion — The researchers identified immigrant groups at higher risk of serious PET, whose consequences would presumably include greater financial costs for hospital care and a negative impact on maternal and newborn well-being.