If you want a smaller baby, and you’re a woman of Western European ancestry, should you marry a man of East Asian or South Asian ancestry? Actually, according to a new study, it works more like what’s happening to babies birthweight in the country in which you live now. The new study finds that a father’s ethnic background influences his baby’s birthweight. But birthweights also are affected by where parents live, not only by the father’s ethnic origins. The research work is, “Influence of paternal and maternal ethnicity and ethnic enclaves on newborn weight,” published online June 29, 2014 in Journal of Epidemiology and Community Health.
Previous research by Dr. Joel Ray of St. Michael’s Hospital has shown that a mother’s ethnic background can influence birthweights, and his team’s new study shows the same is true for a father. Dr. Ray, a physician and researcher at the hospital’s Li Ka Shing Knowledge Institute, has studied birthweights among different ethnic groups because babies who are considered to be small or large just before birth can trigger medical interventions such as Cesarean deliveries. Birthweight is also one of the essential yardsticks used to measure a baby’s progress in its first days and weeks after birth.
Current birthweight 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. But in interracial marriages, knowing how ethnic backgrounds impact birthweights is particularly important in Canada, given the growing number of mixed race families.
Researchers led by Dr. Joel Ray, have developed the first “newborn weight curves” for specific ethnic groups across Canada, but using only the mother’s ethnicity. Dr. Ray’s new 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.
Babies of a Canadian-born mother and foreign-born father weigh quite a bit less than those of two Canadian-born parents, but babies of a Canadian-born father and a foreign-born mother weigh somewhere in between
So is it race, ethnic group, or simply what is the country in which the baby is born, regardless of the ancestor’s place of birth of each parent? Dr. Ray also looked at whether birthweights were affected by where the parents lived. When immigrant parents live in neighborhoods 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, according to the June 29, 2014 news release, “Father’s ethnic background influences birthweight, study finds.”
Dr. Ray’s study was based on an examination of 692,301 births recorded with Vital Statistics in Ontario between 2002 and 2009. This study received funding from the Canadian Institutes of Health Research and the SickKids Foundation. Looks like a father’s ethnic background can influence a child’s birthweight, according to the new study.