Table 3.
Study population of 7975 premature newborns born between 23 and 34 weeks of completed weeks gestation in 7 Massachusetts newborn intensive care units (A-G).
| Metric | All NICUsa combined (n=7975) | A (n=461) | B (n=1586) | Cb (n=1068) | D (n=418) | E (n=598) | F (n=1081) | G (n=2763) | P value |
| Gestational age (weeks), median (IQR) | 32 (29.29-33.86) | 29 (27.14-30.57) | 33 (30.43-34.14) | 32.86 (30.71-34.04) | 31.86 (29-33.57) | 29.14 (26.89-30.71) | 31 (28.57-33.29) | 32.57 (30.29-34) | <.001 |
| Birth weight (gram), median (IQR) | 1580 (1180-2050) | 1130 (885-1316) | 1810 (1370-2160) | 1818.50 (1380-2195) | 1462.50 (1100-1943) | 1160 (871.25-1365) | 1400 (1065-1860) | 1750 (1340-2100) | <.001 |
| Birth weight Z-score, mean (SD) | −0.19 (0.84) | −0.40 (0.85) | −0.14 (0.83) | −0.07 (0.81) | −0.32 (0.79) | −0.36 (0.91) | −0.24 (0.85) | −0.14 (0.82) | <.001 |
| Discharge postmenstrual age (weeks), mean (SD) | 36.4 (2.86) | 35.71 (4.37) | 36.64 (2.22) | 36.17 (2.42) | 34.88 (3.03) | 36.95 (2.70) | 37.05 (3.60) | 36.31 (2.58) | <.001 |
| Discharge weight Z-score, mean (SD) | −1.00 (0.80) | −1.15 (0.81) | −1.19 (0.77) | −0.88 (0.78) | −0.90 (0.76) | −1.32 (0.77) | −0.80 (0.80) | −0.93 (0.79) | <.001 |
| Weight delta Zc, mean (SD) | −0.81 (0.52) | −0.75 (0.49) | −1.05 (0.49) | −0.80 (0.40) | −0.58 (0.46) | −0.96 (0.59) | −0.56 (0.52) | −0.79 (0.49) | <.001 |