A: They don't need to be exactly the same, but the measurements should correspond closely. You'd expect a baby in the 60th percentile for height to be near the 60th for weight as well, for example -- and you wouldn't want your baby's percentile for weight to significantly exceed her height, which could indicate that he's becoming overweight. The new growth charts have an index that gauges whether an infant's weight correlates desirably with his height.
Originally published in the June 2001 issue of Parents magazine. Updated 2009.