Babies Born to Immigrant Mothers in Canada at Lower Risk for Cerebral Palsy

A recent study found that babies born to mothers who immigrated to Ontario from other countries are at a significantly lower risk for cerebral palsy (CP) than those of Canadian-born mothers, according to findings published in the journal PLOS One.

"Predicting who is at highest risk of having a child with CP remains an international priority," said lead author Dr. Joel Ray, a physician and researcher at St. Michael's Hospital in Toronto, in a news release. 

Ray notes that his research shows that mothers who migrated from the Caribbean and East Asia were at the lowest risk for this debilitating motor disability that typically appears by the age of four. Any cases of CP with underlying injury to the brain, on the other hand, are thought to occur before birth, resulting in damage to motor neurons that can affect coordination, muscle strength and overall balance.

For his research, Ray examined data from the Institute for Clinical Evaluative Sciences on all single births in Ontario from 2002 to 2008. Each child was assessed up until the age of 4, coming from a total sample of 744,058 live single births. 

From this sample, 1,346 cases of CP were found. For immigrants, there were 1.45 cases of CP for every 1,000 births; that's a 23 percent lower risk than for non-immigrant counterparts at 1.92 CP diagnoses per 1,000 births.

However, not all immigrant mothers had the same health advantage. Findings also revealed that immigrants living in high-income areas were not at a lower risk of CP than their non-immigrant counterparts. Dr. Ray said this may be because wealthier immigrants who have lived in Canada for longer periods of time lose the "healthy immigrant effect," where immigrants are generally healthier than those born in Canada.

However, he said he believes the key to reducing overall CP risk is a better understanding of the underlying factors that may predispose some to the health issue.Though prenatal injury can increase the risk, there is still a great deal unknown about what causes the health problem.