Birth Weight Significantly Affects Infant Mortality in Native Peoples

High birth weight in First Nations (North American Indian) babies are linked to a higher risk of post-neonatal death (infant deaths that occur from 4 weeks to 1 year of age, according to a study published in Canadian Medical Association Journal.

High birth weight or infant macrosomia is defined as a child being born above the 90th percentile relative to a fetal growth standard. Maternal obesity, impaired glucose tolerance and gestational diabetes can all contribute to infant macrosomia and these risks affect a greater proportion of Aboriginal populations.

This study was conducted to determine if the high incidence of macrosomia is a risk factor for perinatal and post-neonatal death among First Nations in Quebec. It compared 5193 births to First Nations mothers versus 633,424 births to French mother tongue women from 1991 to 2000 in Quebec.

"We found that macrosomia was not associated with increased risk of perinatal death among births to First Nations women, although its [macrosomia's] prevalence was three times higher than among births to women whose mother tongue women is French," writes Dr. Zhong-Cheng Luo, of the University of Montreal's Department of Obstetrics and Gynecology and Sainte-Justine University Hospital Centre in Montreal, Quebec with coauthors. "Unexpectedly, macrosomia was associated with a much greater risk of postneonatal death (8.3 times as high) among infants of First Nations versus French mother tongue women."

The authors conclude that parents and caregivers should be watchful for the potential high risk of postneonatal death among infants with macrosomia from First Nations women. Further research is needed into determining cause and effective prevention programs must be developed.

In a related commentary, Katherine Dray-Donald, Dietetics and Human Nutrition, McGill University, writes, "despite these intriguing results concerning possible protective effects of large-for-gestational-age on infant mortality, the factors leading women to have large-for-gestational-age infants are serious for their health; pregravid obesity, weight gain during pregnancy and gestational diabetes. High birthweights in infants pose their own risks in relation to obesity as well. Good nutrition and healthy weight gains in pregnancy, food security for all, and encouraging breastfeeding and many other factors are needed to close the health disparities between infants of First Nations families and those of other Canadians."