Table 4.

Reference Population Characteristics

Birth Weight Interval
501–700 g
(n = 197)
701–900 g
(n = 307)
901–1100 g
(n = 359)
1101–1300 g
(n = 373)
1301–1500 g
(n = 424)
Reference population* 8 (4.1) 32 (10.4)80 (22.8)139 (37.3)219 (51.7)
Gestational age, wk24.3  ± 1.0 26.4  ± 2.027.7  ± 1.229.1  ± 1.630.3  ± 1.6
Male,n (%)2 (25.0)18 (56.3)27 (33.8) 58 (41.7) 94 (42.9)
White, n(%)5 (62.5) 7 (21.9)24 (30.0) 39 (28.1) 85 (38.8)
Duration (d) PN ≥75%12.5  ± 7.09.1  ± 5.66.9  ± 5.34.4  ± 3.73.7  ± 3.7
Age (d) at first enteral feed6.0  ± 3.05.5  ± 4.23.8  ± 2.32.8  ± 2.12.5  ± 1.8
Age (d) at full enteral feed24.9  ± 10.418.1  ± 7.213.6  ± 6.410.2  ± 5.69.0  ± 4.7
Age (d) to regain birth weight 18.6  ± 3.617.5  ± 9.613.5  ± 6.912.5  ± 6.712.0  ± 5.9
  • Abbreviations: PN, parenteral nutrition.

  • * The reference population [n (%)] was defined as infants who were appropriate-for-gestational age and survived to discharge without developing chronic lung disease, severe intraventricular hemorrhage, necrotizing enterocolitis, or late-onset sepsis.

  • Mean ± SD.

  • Birth weight regained and maintained for 2 days.