COVID-19 information for patients and families

To help protect our people, patients and communities, we are screening everyone who enters our main hospital buildings. Some of our entrances may be closed or have reduced access.

Please check our COVID-19 information page for more updates before coming to our sites.

Birthweight curves for newborns according to maternal ancestry

Canadian data suggests that infants born to parents of East Asian and South Asian ancestry may be of lower birth weight than those of White European decent. Using traditional newborn birthweight curves, some Canadian newborns of East Asian and South Asian ancestry may be misclassified as small for gestational age birthweight (SGA), while they are actually normal in birthweight if compared to other East Asian and South Asian infants <Ray JG, Jiang D, Sgro M, Shah R, Singh G, Mamdani MM. Thresholds for small for gestational age among newborns of East Asian and South Asian ancestry. J Obstet Gynaecol Can 2009; 31:322-30>.

We developed contemporary population-based birth weight percentile charts for male and female live born infants specific to seven maternal world regions of birth, including Canada . We included liveborn infants of Canadian-born (n = 486,599), Europe and Western Nations (n = 58,505), Africa/Caribbean (n = 37,382), North Africa/Middle East (n = 25,650), Latin America (n = 26,042) Southeast Asia/Pacific (n = 61,819) and South Asia (n = 70,691) <Ray JG, Sgro M, Mamdani MM, Glazier RH, Bocking A, Hilliard R, Urquia ML. Birth weight curves tailored to maternal World region. J Obstet Gynaecol Can 2012;34:159-71>.

The smoothed birthweight percentile curves can be accessed here by clicking on any of the following PDF links:



Joel G. Ray,
Michael Sgro, MD
Richard H Glazier, MD MSc
Alan Bocking, MD
Robert Hilliard. MD
Muhammad M. Mamdani, PharmD , MA , MPH
Marcelo L. Urquia, PhD

University of Toronto, Toronto, Ontario