Table 1. Characteristics of infants and samples obtained from them.
| Heel samples (n = 487) |
Cord samples (n = 1036) |
Paired heel and cord samples (n = 454 pairs) |
|
|---|---|---|---|
| Completeness of analyte data†, n (%) | |||
| No missing analytes | 459 (94.3%) | 1015 (98.0%) | 427 (94.1%) |
| ≥1 analyte missing, missing values imputed | 28 (5.7%) | 21 (2.0%) | 27 (5.9%) |
| Sex, n (%) | |||
| Male | 246 (50.5%) | 538 (51.9%) | 234 (51.5%) |
| Female | 241 (49.5%) | 498 (48.1%) | 220 (48.5%) |
| Gestational Age (wks), overall mean (SD) | 39.1 ± 1.5 | 39.0 ± 1.7 | 39.2 ± 1.4 |
| Gestational Age Category (wksdays), n (%) | |||
| ≥37 weeks | 454 (93.2%) | 931 (89.9%) | 425 (93.6%) |
| 320-366 weeks | 32 (6.6%) | 102 (9.8%) | 29 (6.4%) |
| <320 weeks | 1 (0.2%) | 3 (0.3%) | 0 (0.0%) |
| Birth Weight (g), mean (SD) | |||
| Overall | 2837.8 ± 433.7 | 2862.1 ± 445.9 | 2846.8 ± 414.0 |
| Term infants only | 2879.5 ± 392.9 | 2916.5 ± 401.7 | 2879.2 ± 389.9 |
| Preterm infants only | 2264.2 ± 554.8 | 2380.3 ± 524.5 | 2372.1 ± 470.4 |
| Birth Weight Category, n (%) | |||
| ≥4000 g | 3 (0.6%) | 15 (1.5%) | 3 (0.7%) |
| 2500 g to < 4000 g | 396 (81.3%) | 856 (82.6%) | 374 (82.4%) |
| 1500 g to < 2500 g | 84 (17.3%) | 158 (15.2%) | 75 (16.5%) |
| 1000 g to < 1500 g | 4 (0.8%) | 4 (0.4%) | 2 (0.4%) |
| <1000 g | 0 (0.0%) | 3 (0.3%) | 0 (0.0%) |
| Multiple Birth, n (%) | 7 (1.4%) | 19 (1.8%) | 8 (1.8%) |
| Newborn age at sample collection (hrs), mean (SD) | |||
| Overall | 14.97 ± 6.54 | 0.06 ± 0.25 | 15.06 ± 6.38 (heel) 0.06 ± 0.25 (cord) |
| Term infants only | 14.74 ± 6.42 | 0.06 ± 0.25 | 14.86 ± 6.22 (heel) 0.06 ± 0.25 (cord) |
| Preterm infants only | 18.00 ± 7.50 | 0.09 ± 0.28 | 17.97 ± 7.93 (heel) 0.07 ± 0.26 (cord) |
Data are presented as mean±standard deviation unless otherwise specified. †One cord blood sample was excluded in the data preparation step because 100% of analyte data was missing). All other samples with missing analyte data had no more than 5/47 (11%) missing analyte predictors.