Table 1 Comparison of clinical, demographic and laboratory characteristics of the study groups
Variables | Group 1 (n = 70) | Group 2 (n = 94) | Group 3 (n = 109) | Group 4 (n = 61) | P value |
|---|---|---|---|---|---|
Demographic data | |||||
Gestational age at birth, week median (IQR) | 29.20 (26–32.3) | 29.5 (28.0–31.5) | 28.7 (27–32.3) | 28.2 (26.0–32.5) | 0.366 |
Birth weight, g | 1.22 (1.06–1.36) | 1.10 (0.93–1.32) | 0.80 (0.69–1.06) | 0.84 (0.70–1.03) | < 0.001 |
Male, n (%) | 39 (55.7) | 49 (52.1) | 52 (47.7) | 35 (57.4) | 0.602 |
Cesarean section delivery, n (%) | 52 (74.3) | 79 (84.0) | 72 (66.1) | 50 (82.0) | 0.015 |
Biochemical data | |||||
RDW at baseline, % median (IQR) | 16.2 (15.7–16.6) | 1.7.9 (17.4–19.2) | 16.1 (15.7–16.4) | 17.8 (17.4–19.0) | < 0.001 |
RDW at maximum, % median (IQR) | 17.15 (16.7–17.7) | 18.9 (18.4–19.7) | 20.3 (19.2–22.0) | 21.6 (20.4–23.4) | < 0.001 |
△RDW, % median (IQR) | 0.1 (0.6–1.6) | 0.7 (0.4–1.3) | 4.4 (3.1–6.1) | 3.1 (2.5–4.5) | < 0.001 |
WBC, × 109 /L median (IQR) | 7.45 (5.2–9.9) | 6.8 (4.6–10.1) | 7.3 (5.2–9.6) | 5.5 (4.1–7.1) | 0.039 |
Hb, g/dL | 15.16 ± 0.29 | 15.68 ± 0.25 | 14.84 ± 0.19 | 14.64 ± 0.28 | 0.017 |
Neutrophil, % | 27.69 ± 1.60 | 30.06 ± 1.73 | 29.56 ± 1.48 | 33.02 ± 2.34 | 0.295 |
PLT, 109/L median (IQR) | 231 (189–281) | 208 (164–282) | 233 (199–284) | 167 (125–212) | < 0.001 |
Severity bacterial infection, n (%) | 3 (4.3) | 19 (20.2) | 36 (33.0) | 29 (47.54) | < 0.001 |
Sepsis, n (%) | 3 (4.3) | 17 (18.1) | 32 (29.4) | 29 (47.54) | |
Meningitis*, n (%) | 0 (0) | 2 (2.1) | 8 (7.3) | 5 (8.20) | |
Urinary tract infection*, n (%) | 0 (0) | 2 (2.1) | 0 (0) | 1 (1.64) | |
Total length of hospital stays, day | 56.6 ± 3.5 | 50.1 ± 2.9 | 77.1 ± 4.1 | 77.7 ± 4.6 | < 0.001 |