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Ethnicity increases risk of preeclampsia


Certain immigrant women in Ontario are at higher risk of developing serious preeclampsia (very high blood pressure, more extreme proteinuria or a seizure during pregnancy) than their Ontario-born counterparts. Researchers at Institute for Clinical Evaluative Sciences (ICES) and St. Michael’s Hospital found women from Hispanic American or Sub-Saharan African countries had a 3.1 times higher risk of serious preeclampsia, and those from the Caribbean had a 3.3 times higher risk than women born in industrialized nations.

Preeclampsia is marked by the development of high blood pressure and protein in the urine after the 20th week (late second or third trimester) of pregnancy.

In this study, researchers defined "serious preeclampsia" by those clinically important aspects of preeclampsia, namely, severe preeclampsia (a very high blood pressure or more extreme proteinuria or a seizure), or any degree of preeclampsia with either preterm delivery, fetal death or a maternal hospital stay of seven days or more.

“We identified immigrant groups at higher risk of serious preeclampsia, whose consequences are, presumably, greater financial costs for hospital care and a negative impact on maternal and newborn well-being,” say Drs. Joel Ray and Marcelo Urquia of the Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital and ICES researchers.

The population-based study of 118,849 women who immigrated to Ontario between 1985 and 2000 with subsequent delivery between 2002 and 2009 found:

  • Women from industrialized nations have a rate of serious preeclampsia of 1.9 per 1,000 women.
  • Women from Hispanic American or Sub-Saharan African countries had a 3.1 times higher risk of serious preeclampsia, after adjusting for age, parity, a multifetal pregnancy, diabetes mellitus, level of education, place of residence, income quintile, duration of residence in Canada and fiscal year of delivery.
  • Women from the Caribbean had a 3.3 times higher adjusted risk (a rate of about 6.8 per 1,000 women).

“The world region where immigrant women are born can be used to further aid in the identification of those at greatest risk for serious preeclampsia, in whom aspirin prophylaxis after 12 weeks gestation might be considered,” says Ray, “in addition to greater maternal and fetal surveillance.”

The study “Serious Preeclampsia Among Different Immigrant Groups," is in the April, 2012 of JOGC.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

St. Michael’s Hospital provides compassionate care to all who enter its doors. The Hospital also provides outstanding medical education to future healthcare professionals in more than 23 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, and care of the homeless are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing Knowledge Institute, research at St. Michael’s Hospital is recognized and put into practice around the world. Founded in 1892, the Hospital is fully affiliated with the University of Toronto.



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