Birth weight percentiles by gestational age in Canada.

Abstract

The large data base assembled for this analysis provides current, stable birth weight-gestational age percentiles for classifying newborns from a developed country as small, appropriate, or large for gestational age. Compared with birth weight distributions from the 1970s, these current norms are heavier for full-term infants and the interdecile range for preterm infants is narrower. We recommend that birth weight norms be updated every 5-10 years.