One size doesn't fit all: Ethnic birth weight chart better for infant care

A new study, recently published online by the American Journal of Obstetrics and Gynecology, shows ethnicity-specific birth weight charts are better at identifying newborns who are small for gestational age (SGA), a classification associated with hypothermia, hypoglycemia, infection and admission to the neonatal intensive care unit.

"When we expect Chinese, South Asian and Caucasian babies to be the same size at birth, we risk misclassifying small but healthy Chinese and South Asian babies as small for gestational age," says the study's lead author Gillian Hanley, a post-doctoral fellow with UBC's School of Population and Public Health (SPPH) and the Child & Family Research Institute (CFRI).

Hanley and Patricia Janssen, an SPPH professor and CFRI scientist, examined data from more than 100,000 newborns in Washington state against two birth-weight standards: a population-based birth weight chart used by most hospitals and one that accounted for the ethnicity of the newborns, developed by Janssen in 2007.

Developing and implementing ethnicity-based standards can help better direct attention to those babies who need it the most.

"We found a considerable number of babies classified as small for gestational age by the conventional birth weight chart were actually healthy babies," says Hanley. "This leads to parental anxiety, unnecessary testing and increased health care costs."

"Developing and implementing ethnicity-based standards can help better direct attention to those babies who need it the most," Hanley adds.