Table 2.

Morbidity and Length of Stay for Infants Born in the NICHD Neonatal Research Network Between January 1, 1995 and December 31, 1996*

501 to
750 Grams
n = 1002
751 to
1000 Grams
n = 1084
1001 to
1250 Grams
n = 1053
1251 to
1500 Grams
n = 1299
501 to
1500 Grams
n = 4438
Morbidity (%)
Respiratory distress syndrome78 (54–97)63 (23–81)44 (23–63)26 (9–45)50 (27–66)
Surfactant therapy70 (40–96)68 (48–94)47 (31–64)28 (19–41)52 (40–63)
Oxygen at 28 d81 (64–92)59 (33–74)25 (4–40)7 (2–28)36 (25–44)
Postnatal steroids29 (6–46)29 (4–61)14 (2–33)6 (0–23)19 (3–35)
CLD52 (8–86)34 (4–69)15 (2–35)7 (0–23)23 (3–43)
Growth failure100 (92–100)98 (90–100)97 (83–100)95 (90–36)97 (93–100)
Discharged home on oxygen34 (5–65)22 (4–62)10 (0–30)4 (0–21)15 (2–36)
Discharged home on monitors40 (10–95)32 (5–91)23 (2–69)17 (2–45)26 (7–70)
Sonogram performed (%)§77 (50–100)95 (91–100)95 (81–100)88 (75–99)89 (80–97)
Grade I12 (0–26)15 (3–32)15 (7–34)14 (7–27)14 (7–30)
Grade II10 (0–19)7 (1–18)4 (0–13)3 (0–11)5 (2–13)
Grade III13 (6–29)6 (3–15)5 (0–13)2 (0–5)6 (3–13)
Grade IV13 (3–26)6 (0–14)3 (0–10)1 (0–3)5 (2–11)
Sonogram after 2 wk86 (65–100)80 (54–98)68 (40–96)51 (19–81)69 (46–91)
Periventricular leukomalacia7 (2–30)7 (0–18)4 (0–11)3 (0–10)5 (2–13)
NEC ≥stage II14 (9–38)9 (3–22)5 (0–8)3 (0–9)7 (4–13)
Late septicemia48 (30–64)33 (16–51)18 (6–39)7 (0–17)24 (12–38)
PDA51 (19–76)39 (13–73)25 (8–55)13 (0–31)30 (10–54)
Indomethacin for PDA79 (33–91)76 (50–93)70 (40–86)65 (22–82)75 (44–85)
Surgery for PDA23 (0–42)17 (0–38)8 (0–26)4 (0–17)15 (0–27)
Length of stay (mean d)
Survivors116 (97–138)86 (66–108)58 (46–70)40 (34–49)68 (58–82)
Deaths16 (7–39)24 (8–59)17 (2–59)24 (1–87)18 (10–36)
Deaths + intensive care21 (9–43)25 (7–58)18 (1–115)27 (1–86)22 (11–41)
Mortality
By d 326 (8–55)6 (0–11)3 (0–9)2 (0–4)8 (3–14)
By d 730 (8–57)7 (0–11)4 (0–10)2 (0–7)10 (3–15)
By d 1435 (17–64)8 (3–14)5 (0–12)2 (0–7)12 (5–17)
By d 2840 (21–67)11 (7–20)5 (2–12)3 (0–7)14 (7–20)
  • * Data expressed as percent affected among all VLBW births with center ranges in parentheses.

  • CLD as 2 at 36 weeks' postmenstrual age.

  • Growth failure as weight <10th percentile at 36 weeks' postmenstrual age.

  • § Most severe grade7 in infants who had an ultrasound (n = 3941).

  • Of infants who had an ultrasound after 2 weeks of age (n = 2597).

  • Infants who received mechanical ventilation.