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Pregnancy complications may be more common in immigrants from certain regions

Toronto, April 24, 2014

Dr. Marcelo Urquia
Dr. Marcelo Urquia

Pregnant immigrants from Sub-Saharan Africa, Latin America and Caribbean islands may require increased monitoring during pregnancy, according to new research from St. Michael’s Hospital.

The study, published today in the British Journal of Obstetrics and Gynaecology, assessed the differences in pre-eclampsia and eclampsia rates among immigrants and native-born women in six high-immigration countries – Australia (Victoria), Canada (Ontario), Denmark, Sweden, Spain (Catalonia and Valencia) and the United States (California, New Jersey and New York City).

Researchers found that Sub-Saharan Africans have consistently higher risk of pre-eclampsia and eclampsia compared to immigrants from other world regions or non-immigrant women from the six countries studied. In some, but not all, of the six countries Latin Americans and Caribbean islanders were also shown to be at higher risk.

“Obstetricians and midwives should consider pregnancies for immigrants from these regions as high risk,” said Dr. Marcelo Urquia, lead author and an epidemiologist at the Centre for Research on Inner City Health of St. Michael’s Hospital. “They need enhanced surveillance and culturally sensitive care.”

Pre-eclampsia is most common in first-time pregnancies. It affects two to seven per cent of women who have never given birth. Mothers with pre-eclampsia can experience several complications, including high blood pressure and high amounts of protein in the urine. Pre-eclampsia can cause premature birth and stunt fetus growth in the womb.

If undiagnosed, pre-eclampsia can lead to eclampsia – a serious condition that puts mothers and children at higher risk. Mothers can suffer long-term cardiovascular health issues. Eclampsia can lead to lost pregnancies and even cause long-term adult health problems in the babies. “There's no cure for pre-eclampsia – which does disappear when the baby is born,” said Dr. Urquia, who is also an adjunct scientist at the Institute for Clinical Evaluative Sciences. “But when caught early, it's easier to manage. That’s why it’s so important to identify these high-risk groups.”

While it’s not known why some immigrant groups had higher rates than others, even in their home countries Sub-Saharan Africans exhibit the highest rates of pre-eclampsia and eclampsia worldwide. It’s possible that immigrants may carry higher susceptibility even after arriving in their new country.

Using each country’s most recently available birthing data, researchers analyzed more than nine million births – more than a third of which were to immigrant women. Immigrants were divided into regions of origin:

  • Latin America and the Caribbean islands
  • Middle East
  • Western Europe
  • Eastern Europe
  • East Asia
  • Southeast Asia
  • North Africa
  • Sub-Saharan Africa

Not all immigrants groups had increased rates of pre-eclampsia or eclampsia, however. Immigrant women from regions of the world such as East Asia, Southeast Asia, North Africa and the Middle East seem to be at lower risk of developing pre-eclampsia than native-born women and Eastern Europe women are at lower odds of developing eclampsia.

“It’s also important to note that differences exist even within these regional groupings,” said Dr. Urquia. “In Ontario, for example, Caribbean and Central American women had greater risk than South Americans – who had similar rates to Canadian-born women.”

Pre-eclampsia rates in
the six high-immigration
countries studied
World region that each woman was born in Eclampsia rates in
the six high-immigration
countries studied
1 Born in receiving country 1
0.72 Western Europe 0.76
0.71 Eastern Europe 0.46
1.08 Latin America & Caribbean 1.18
0.69 South Asia 0.81
0.60 East-Southeast Asia 0.61
0.62 North Africa & Middle East 0.81
1.25 Sub-Saharan Africa 1.60

Western European immigrants acted as a control group for the study -- a population that had endured the immigrant experience but ethnically most resembles those born in the native countries.

“We need to look more at factors affecting immigrant health,” said Dr. Urquia. “Future research should continue to look at global evidence.” The study was partially funded by a Canadian Institutes of Health Research grant.

About St. Michael's Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

Media contacts

For more information, or to arrange an interview with Dr. Urquia, contact:

Leslie Shepherd
Manager, Media Strategy
416-864-6094
shepherdl@smh.ca

Geoff Koehler
Adviser, Media Relations
416-864-6060 ext. 6537
koehlerg@smh.ca