Outcome measures at the age of 4 months in infants whose umbilical cords were clamped after 10, 60 or 180 s
| Umbilical cord clamping time | 60 s vs 10 s | 60 s vs 180 s | |||||
| 10 s (n=153 (HC)) | 60 s (n=147) | 180 s (n=148 (HC)) | Mean difference (95% CI) | P value | Mean difference (95% CI) | P value | |
| Infant age (days) | 122 (6) | 126 (7) | 122 (6) | 5 (3 to 6) | <0.001 | 4 (3 to 6) | <0.001 |
| Main outcome measures | |||||||
| Geometric mean (range) ferritin (μg/L) | 80 (33 to 191) | 96 (44 to 208) | 117 (58 to 232) | 0.83 (0.69 to 1.45)* | 0.052 | 1.21 (1.03 to 1.44)* | 0.02 |
| Haemoglobin (g/dL) | 11.3 (7) | 11.5 (8) | 11.3 (8) | 2 (0 to 4) | 0.047 | 2 (0 to 4) | 0.03 |
| Blood count | |||||||
| Haematocrit (%) | 33.0 (2.0) | 33.3 (2.2) | 32.7 (2.1) | 0.3 (−0.2 to 0.8) | 0.19 | 1 (0 to 1) | 0.02 |
| Mean cell volume (fL) | 77.9 (3.1) | 77.7 (3.7) | 79.2 (3.0) | −0.2 (−1 to 0.6) | 0.67 | −1.5 (−2.3 to −0.7) | <0.001 |
| Reticulocyte count (×1012/L) | 0.037 (11) | 0.036 (11) | 0.040 (11) | −1 (−4 to 1) | 0.39 | −4 (−6 to −1) | 0.01 |
| Iron status | |||||||
| Transferrin receptor (mg/L) | 4.00 (0.80) | 4.07 (0.92) | 3.71 (0.69) | 0.07 (−0.13 to 0.26) | 0.51 | 0.35 (0.17 to 0.54) | <0.001 |
| Transferrin saturation (%) | 16 (6) | 16 (8) | 18 (6) | 1 (−1 to 2) | 0.40 | −2 (−3 to 0) | 0.03 |
Values are means (SD) unless stated otherwise.
Successful analyses in the 60 and 180 s groups: haemoglobin (n=140, 144), haematocrit, mean cell volume, reticulocyte count (n=135, 144), ferritin (n=147, 148), transferrin receptor (n=147, 148), transferrin saturation (n=145, 148).
*Geometric mean ratio (95% CI for geometric mean).
HC, Historical cohort.