Fig. 5: Growth velocity of weight trajectories by sex and gestational age group from 40 to 360 weeks postmenstrual age, compared with that of the standard population.

Weight growth velocity curves from term-equivalent age to 6 years, stratified by gestational age (GA) group and sex. The x-axis shows postmenstrual age in weeks (40 weeks postmenstrual age corresponds to term-equivalent age), and the y-axis shows weight growth velocity (kg/year). a, b, and c show boys born at GA 22–24, 25–27, and 28–31 weeks, respectively; d, e, and f show girls in the same GA groups. Solid lines (boys) and dashed lines (girls) represent the model-estimated mean weight growth velocity, and shaded areas indicate the 95% confidence intervals.