It is not just a mother's ethnic background that influences a child's birthweight, the same is true for a father, says a study.
Babies, who are considered to be small or large just before birth can trigger medical interventions such as caesarean 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 baby's weight compares to others of the same age - assume that the parents are of western European descent, said Joel Ray from St. Michael's Hospital in Canada, who studied birthweights among different ethnic groups.
That means many babies of an East or South Asian mother may be classified as underweight, when in fact they are "normal" for their ethnic groups.
The same is true when the father is of Asian descent, the study showed.
The study was based on an examination of 6,92,301 births recorded with vital statistics in Ontario in Canada between 2002 and 2009.
The findings appeared in the Journal of Epidemiology and Community Health.
