Table 2.
Measures of complete blood count and iron status at 2 days and 4 months of age in infants who were randomised to early umbilical cord clamping (≤10 s after delivery) or delayed clamping (≥180 s). Values are means (SD) unless stated otherwise
| 2 days | 4 months | ||||||
|---|---|---|---|---|---|---|---|
| Cord clamping | Difference (95% CI), P value | Cord clamping | Difference (95% CI), P value | ||||
| Early | Delayed | Early | Delayed | ||||
| Blood count | (n=160) | (n=162) | (n=175) | (n=168) | |||
| Haemoglobin (g/L) | 175 (19) | 189 (17) | 13.5 (9.6 to 17.5), <0.001 | 113 (7) | 113 (8) | 0.0 (−1.6 to 1.6), 0.98 | |
| Packed cell volume | 50 (5) | 53 (5) | 3.5 (2.4 to 4.6), <0.001 | 33 (2) | 33 (2) | −0.2 (−0.7 to 0.2), 0.28 | |
| Mean cell volume (fL) | 98.3 (3.8) | 98.4 (3.7) | 0.1 (−0.7 to 0.9), 0.82 | 78.0 (3.1) | 79.0 (3.2) | 1.0 (0.3 to 1.7), 0.004 | |
| Mean cell haemoglobin concentration (g/L) | 354 (7) | 356 (8) | 2.2 (0.6 to 3.9), 0.008 | 344 (0.8) | 346 (0.8) | 2.6 (0.9 to 4.3), 0.002 | |
| Reticulocyte haemoglobin (pg/L) | 32.5 (2.4) | 32.7 (2.6) | 0.2 (−0.4 to 0.7), 0.54 | 28.9 (2.1) | 29.6 (1.9) | 0.6 (0.2 to 1.0), 0.005 | |
| Reticulocyte count (×109/L) | 171 (47) | 168 (44) | −3 (−13 to 7), 0.54 | 37 (11) | 40 (11) | 2.5 (0.1 to 4.8), 0.04 | |
| Iron status* | |||||||
| Iron (μmol/L) | 9.9 (2.9) | 9.9 (2.7) | −0.1 (−0.7 to 0.6), 0.88 | 9.3 (2.9) | 10.2 (3.0) | 0.9 (0.2 to 1.5), 0.007 | |
| Transferrin (g/L) | 1.76 (0.26) | 1.76 (0.22) | 0.0 (−0.05 to 0.05), 0.99 | 2.41 (0.34) | 2.28 (0.31) | −0.12 (−0.19 to −0.06), <0.001 | |
| Transferrin receptors (mg/L) | 5.35 (1.60) | 5.44 (1.64) | 0.09 (−0.26 to 0.45), 0.61 | 3.97 (0.80) | 3.73 (0.69) | −0.24 (−0.40 to −0.08), 0.003 | |
| Transferrin saturation (%) | 23 (7) | 23 (7) | 0.4 (−1.9 to 1.2), 0.65 | 16 (6) | 18 (6) | 2.4 (1.2 to 3.7), <0.001 | |
| Geometric mean (range) ferritin (μg/L) | 300 (44–628) | 312 (110–1029) | 4.0 (−6.5 to 15.1)†, 0.45 | 81 (6–760) | 117 (20–880) | 45 (23 to 71)†, <0.001 | |
| LogTfR/Fer | 1.41 (0.27) | 1.40 (0.25) | −0.01 (−0.07 to 0.05), 0.74 | 1.85 (0.43) | 1.66 (0.33) | −0.19 (−0.27 to −0.11), <0.001 | |
| Total body iron (mg/kg) | 11.7 (2.2) | 11.8 (2.1) | 0.1 (−0.4 to 0.6), 0.74 | 8.1 (3.5) | 9.6 (2.7) | 1.6 (0.9 to 2.3), <0.001 | |
LogTfR/Fer=log ratio of transferrin receptor and ferritin.
*Numbers of successful analyses of iron status for early and delayed clamping groups were: at 2 days, iron and transferrin saturation (n=137, 146), transferrin (n=155, 158), transferrin receptors (n=156, 157), and ferritin, LogTfR/Fer, and total body iron (n=152, 156); at 4 months, iron, ferritin, LogTfR/Fer, total body iron, and transferrin receptors (n=175, 172), transferrin and transferrin saturation (n=175, 171)
†Geometric mean ratio in percentage.