TABLE 1.
Baseline characteristics of very-low-birth-weight infants and their families in the study sets1
| Characteristic | EWAS analysis (n = 143) | Corroboration (MRI) analysis (n = 41) |
|---|---|---|
| Sex | ||
| Male | 73 (51.0) | 18 (43.9) |
| Female | 70 (49.0) | 23 (56.1) |
| Birth gestational age, wk | 27.8 ± 2.5 | 27.8 ± 1.8 |
| Birth weight, g | 1008 ± 264 | 1005 ± 262 |
| Small for gestational age | ||
| Yes | 19 (13.3) | 6 (14.6) |
| No | 124 (86.7) | 35 (85.4) |
| Percentage mother's milk | 72.0 ± 36.8 | 68.2 ± 37.8 |
| Maternal education | ||
| University | 78 (54.5) | 23 (56.1) |
| No university | 65 (45.5) | 18 (43.9) |
| Family income | ||
| Below poverty line | 28 (19.6) | 6 (14.6) |
| Above poverty line | 110 (76.9) | 34 (82.9) |
| Missing | 5 (3.5) | 1 (2.4) |
| Duration of breastfeeding, d | 228.0 ± 185.7 | 249.4 ± 186.5 |
| Twin pairs, n | 20 | 2 |
| Mother's ethnicity | ||
| Asian | 23 (16.1) | 9 (22.0) |
| European | 65 (45.5) | 18 (43.9) |
| Middle Eastern | 26 (18.2) | 8 (19.5) |
| Other/mix | 29 (20.3) | 6 (14.6) |
| Maternal smoking | ||
| Yes | 10 (7.0) | 3 (7.3) |
| No | 133 (93.0) | 38 (92.7) |
| Brain injury2 | ||
| Yes | 22 (15.4) | 5 (12.2) |
| No | 121 (84.6) | 36 (87.8) |
| Positive pressure ventilation3 | ||
| Yes | 96 (67.1) | 29 (70.7) |
| No | 47 (32.9) | 12 (29.3) |
| Morbidity4 | ||
| Yes | 49 (34.3) | 13 (31.7) |
| No | 94 (65.7) | 28 (68.3) |
| Length of hospitalization, d | 84.3 ± 38.5 | 83.8 ± 36.4 |
| Diet quality at 5.5 y5 | ||
| Better | 103 (72.0) | 35 (85.4) |
| Poor | 40 (28.0) | 6 (14.6) |
| Macronutrient intake (1st week in hospital), g ⋅ kg−1 ⋅ d−1 | ||
| Protein | 3.0 ± 0.4 | 3.1 ± 0.4 |
| Lipids | 2.3 ± 0.8 | 2.4 ± 0.7 |
| Energy | 69.6 ± 11.2 | 71.6 ± 11.0 |
Values are mean ± SD or n (%) unless otherwise indicated. EWAS, epigenome-wide association study.
Brain injury is defined as echodense intraparenchymal lesions, periventricular leukomalacia, porencephalic cysts, or ventriculomegaly with or without intraventricular hemorrhage.
Positive pressure ventilation is yes if the number of days with respiratory support (mechanical ventilation or continuous positive airway pressure) is over half of the days in hospital.
Morbidity includes late-onset sepsis (positive culture in blood or cerebrospinal fluid at ≥5 d of life), chronic lung disease (requirement for oxygen support at 36 wk), necrotizing enterocolitis (Bell Stage ≥ II), and retinopathy of prematurity (International stage 4/5, laser or intravascular injection).
Healthy Eating Index-2010 score >50 means better diet quality; otherwise, poor quality.