A father's ethnic background and the place where parents live can influence a child's birth-weight, a new study has found.
Previous research by Dr Joel Ray of St Michael's Hospital has shown that a mother's ethnic background can influence birth-weights, and his team's new study shows the same is true for a father.
Birth-weight is one of the essential yardsticks used to measure a baby's progress in its first days and weeks after birth.
Current birth-weight curves - graphs used to plot how one baby's weight compares to others of the same age - assume that the parents are of Western European descent.
That means many babies of an East Asian or South Asian mother may be classified as underweight, when in fact they are "normal" for their ethnic groups. The new study shows the same is true when the father is of Asian descent.
Researchers led by Ray have developed the first "newborn weight curves" for specific ethnic groups across Canada, but using only the mother's ethnicity.
Ray's new research paper shows that babies born to a foreign-born mother and a foreign-born father weigh about six per cent less than those whose both parents were born in Canada.
Ray also looked at whether birth-weights were affected by where the parents lived.
When immigrant parents live in neighbourhoods with a high concentration of people from their same ethnic background, their babies weigh less than those of Canadian-born parents. This is particularly true for male babies, he said.
Ray's study was based on an examination of 692,301 births recorded with Vital Statistics in Ontario between 2002 and 2009.
The research was published in the Journal of Epidemiology and Community Health.
