Table 3

Clinical characteristics by birth weight group

Risk factors*≤750 g751–1000 g1001–1250 g>1250 g
Number of infants665748813834
Apgar score 5 min6 (3)7 (2)7 (2)8 (2)
Gender, male (%)41.552.051.049.3
Race, AA (%)80.583.479.179.5
Birth weight (g)626 (137)877 (133)1128 (131)1381 (114)
Gestational age (weeks)25 (2)27 (2)29 (3)31 (3)
Small for gestational age (%)55.339.030.327.6
Umbilical artery catheter days10 (12)5 (9)0 (5)0 (0)
Days on ventilator21 (28)6 (16)1 (4)0 (1)
Treatment for PDA (%)50.537.713.23.6
Number of transfusions12 (9)5 (5)2 (3)1 (2)
Exposure to blood transfusion (%)93.584.851.020.5
NEC (%)7.76.85.73.0
  • *Presented as the percentage of the number of infants or as median (IQR).

  • AA, African-American; NEC, necrotising enterocolitis; PDA, patent ductus arteriosus.