Weight, length, head and chest circumference at birth in Phoenix, Arizona.

Standard percentile curves are presented for weight, length, head circumference and chest circumference at birth for a population of 27,963 singleton infants born between the gestational ages of 26 and 42 weeks at a large, private hospital in Phoenix, Arizona. At term, all four growth parameters were significantly greater in male than in female infants. These parameters were significantly reduced in infants born to mothers who smoked and increased in infants born to mothers with diabetes. Percentiles in all parameters were higher than in those of previous studies, suggesting that continued use of growth curves based on older data may result in misclassification of infants with respect to appropriateness of growth-for-gestational age.