Figure 5

Median weight gain velocities of the Prem Growth study preterm infants (23–25 (red dot), 26–28 (blue dash), and 29–31 (purple dash dot) week) with the Fetal-Infant Growth Reference 2013 (black), which was based on a 6 country meta-analysis of intrauterine growth (22 to 40 weeks) and the World Health Organization Growth Standard (40 to 50 weeks) (3rd, 50th & 97th percentiles), beginning at 1 week after birth. All three cohorts weight gain velocity decreased from the higher rates at the younger gestational ages (maximum fetal reference rate = 18.3 g/kg/day at 25 weeks) to 50 weeks (infant reference rate = 4.9 g/kg/day), with a dip in the Fetal-infant Growth Reference rate around 40 weeks.