Excretion of 5-L-oxoproline measured in urine of term and preterm infants within first 72 hours of birth and at intervals until 6 weeks of age
| Time of birth | P value | ||||
|---|---|---|---|---|---|
| < 28 weeks (n=27) | 29-32 weeks (n=22) | 33-36 weeks (n=27) | > 37 weeks (n=17) | ||
| Gestation (weeks) | 26.4* † ‡ (25.8-26.9) | 30.4* † (29.3-30.8) | 34.5* (34.0-34.9) | 39.8 (39.6-40.0) | 0.0000 |
| Birth weight (kg) | 1.01* † ‡ (0.86-1.16) | 1.53* † (1.41-1.66) | 2.06* (1.86-2.27) | 3.34 (3.10-3.58) | 0.0000 |
| SGA (number) | 2 | 3 | 4 | 3 | 0.88* |
| 5-L-oxoproline (μmol/mmol creatinine): | |||||
| < 72 hours | 208* (161-255) | 211* (157-265) | 138 (96-180) | 105 (77-133) | 0.0001 |
| Week 1 | 231 (161-300) | 232 (185-280) | 182 (127-236) | 151 (102-200) | 0.078 |
| Weeks 2-3 | 233 (169-297) | 211 (170-253) | 223 (145-301) | 157 (110-204) | 0.290 |
| Weeks 4-6 | 263 (174-351) | 186 (136-236) | 224 (121-327) | 170 (121-218) | 0.204 |
Infants small for gestational age (SGA) were identified as those with birth weight less than the 3rd centile. Values are mean and 95% CI. Comparison between groups using analysis of variance. P < 0.05, with post-hoc Scheffe’s multiple range test: * compared with > 37 weeks; † compared with 33-36 weeks; ‡ compared with 29-32 weeks. **χ2 test.