New South Wales population-based birthweight percentile charts.

OBJECTIVE: To derive newborn percentile charts using NSW population and hospital-based data. METHODOLOGY: Birthweight data for liveborn singleton infants were obtained from the New South Wales Midwives Data Collection (MDC) from 1990 to 1994 inclusive (n = 422139). Data were also collected from King George V Hospital (KGV) for liveborn singleton infants less than 35 weeks of gestation for 1982-89 inclusive, and for all gestations for 1990-95 inclusive (n = 30610). Birthweight percentiles were derived using the MDC data separately for males and females. Head circumference (n = 29090) and birth length percentiles (n = 26973) were derived from the KGV data. RESULTS: The charts derived from MDC data had generally higher percentiles than previously published charts. These represent the largest Australian population-based study published to date. CONCLUSIONS: Periodic review of newborn growth charts is recommended because of changing ethnic and socio-economic factors.