Table 2.
Characteristics of study cohorts
| Cohort 1 n = 84 |
Cohort 2 n = 61 |
||
|---|---|---|---|
| Female | n (%) | 48 (57%) | 38 (62%)e |
| Gestational age at birth (weeks) | Median (Q1, Q3) | 26.1 (24.9–27.6) | 27.0 (26.0–27.7)e |
| Birth weight (g) | Median (Q1, Q3) | 740 (597–932) | 785 (620–980) |
| Birth length (cm) | Median (Q1, Q3) | 33 (31–35) | 33 (31–35) |
| Birth head circumference (cm) | Median (Q1, Q3) | 22.5 (22.0–25.0) | 24.0 (22.5–25.7) |
| Infants from multiple pregnancies | n (%) | 22 (26.2%) | 36 (59.0%)e |
| Twins | n (%) | 18 (21.4%) | 28 (45.9%) |
| Triplets | n (%) | 4 (4.8%) | 8 (13.1%) |
| Length of hospital stay (days) | Median (Q1, Q3) | 89 (64–109) | 77 (55–102) |
| Postmenstrual age at discharge (weeks) | Median (Q1, Q3) | 39.3 (37.2–41.0) | 38.4 (36.0–40.7) |
| Neonatal morbidities | |||
| Necrotizing enterocolitisb | n (%) | 2 (2.4%) | 2 (3.3%) |
| Focal intestinal perforation | n (%) | 5 (6.0%) | 2 (3.3%) |
| Intraventricular hemorrhage ≥III | n (%) | 7 (8.3%) | 2 (3.3%) |
| Periventricular leukomalacia | n (%) | 1 (1.2%) | 3 (4.9%) |
| Bronchopulmonary dysplasiaa | n (%) | 21 (25%) | 14 (23%) |
| Retinopathy of Prematurity requiring therapy | n (%) | 8 (9.5%) | 2 (3.2%) |
| Total time withc | |||
| Peripheral venous line (days) | Median (Q1, Q3) | 11 (7–19) | 9 (5–15)e |
| Central venous line (days) | Median (Q1, Q3) | 6 (0–14) | 0 (0–6)e |
| Antibiotic treatment (days) | Median (Q1, Q3) | 10 (5–22) | 9 (5–17) |
| Nutrition | |||
| Day of life when full enteral feeds were attained | Median (Q1, Q3) | 9 (8–11) | 7 (6–9)e |
| Cumulative protein intake (g/kg) | |||
| First postnatal week | Median | 25.5 (23.4–27.0) | 24.2 (22.3–27.3) |
| First postnatal 28 days | (Q1, Q3) | 104.6 (99.8–108.1) | 109.0 (103.1–115.0)e |
| Cumulative parenteral protein intake (g/kg) | |||
| First postnatal week | Median (Q1, Q3) | 17.9 (15.7–20.0) | 10.7 (8.3–15.0)e |
| First postnatal 28 days | Median (Q1, Q3) | 22.8 (17.1–30.3) | 12.8 (8.3–22.7)e |
| Cumulative energy intake (kcal/kg) | |||
| First postnatal week | Median (Q1, Q3) | 592 (529–625) | 653 (577–721)e |
| First postnatal 28 days | Median (Q1, Q3) | 3358 (3109–3490) | 3442 (3266–3673)e |
| Nutrition at discharge | |||
| Mother’s own milkd 100% | n (%) | 25 (30%) | 32 (53%)e |
| Mother’s own milkd & Formula | n (%) | 18 (21%) | 14 (23%) |
| Formula 100% | n (%) | 41 (49%) | 15 (25%)e |
| Nutrition at 3 months follow up | n = 67 | n = 54 | |
| Mother’s own milkd 100% | n (%) | 6 (9%) | 11 (20%) |
| Mother’s own milkd & Formula | n (%) | 10 (15%) | 6 (11%) |
| Formula 100% | n (%) | 51 (76%) | 37 (69%) |
| Duration of expressed breast milk/breastfeeding (months) | n = 39 | n = 45 | |
| Based on questionnaire | Median (Q1, Q3) | 5 (3–9) | 5 (4–9) |
Cohort 1 (2006–2007): enteral feeds were initiated on day 1 with 10–15 ml/kg/day and advanced by 15–20 ml/kg/day
Cohort 2 (2010): enteral feeds were initiated on day 1 with 20 ml/kg/day and advanced by 25–30 ml/kg/day
a Moderate or severe BPD according to consensus definition based on oxygen supplementation or positive pressure respiratory support at 36 weeks PMA
b ≥ IIa according to Bell criteria
c During the entire inpatient stay
d Supplemented with human milk fortifier
e Significantly different between the two cohorts (p < 0.05 by Chi-square and Mann-Whitney-Test, respectively)