Z-score differences based on cross-sectional growth charts do not reflect the growth rate of very low birth weight infants - Fig 2

2A: Plotting of growth charts and calculation of z-scores, distribution (black line) of birth weights for a cohort of newborns with a gestational age of 28 and 34 weeks; 2B: Characteristics of growth charts: skewness of percentile distributions (top) and weight gain velocity for major percentiles (bottom).