Fig. 3: The growth rates of the weight acceleration and the stable weight gain phases.

In the top row (panels a, d), weight growth estimates at the 50^th percentile for all gestational age groups between 23 and 30 weeks are plotted together for comparison. The dashed line represents the 50^th percentile line of the 2013 Fenton weight reference chart. In the middle row (panels b, e), estimates of weight growth rates in gram/kg/day for the 50^th percentile of all gestational age groups between 23 and 30 weeks are plotted together for comparison. The horizontal dashed line denotes average weight gain of 16.5 gram/kg/day and 16.7 gram/kg/day for male and female, respectively, during the weight acceleration phase. In the bottom row (panels c, f), estimates of weight growth rates in gram/day for the 50^th percentile of all gestational age groups between 23 and 30 weeks are plotted together for comparison. The horizontal dashed line denotes average weight gain of 31.3 gram/day and 29.8 gram/day for male and female, respectively, in the stable weight gain phase. Numbers shown are mean ± sd of daily weight gain from all gestational age groups combined. The vertical line indicates 34 weeks postmenstrual age. For all panels, the color codes from dark to light denote the gestational age groups from 23 to 30 weeks. The blue gradients are for male, and the red gradients are for female infants. Plots for the 3^rd, 10^th, 25^th, 50^th, 75^th, 90^th, and 97^th percentiles are available in Supplemental Figure S19-S25. Source data are provided in the Source Data file.