Table 1.
Demographics and characteristics of participants
| Characteristic | BHMF (n = 14) | H2MF (n = 16) | p |
|---|---|---|---|
| Mother | |||
| Maternal age in years | 31.7 ± 5.2 | 30.6 ± 5.6 | 0.57 |
| Maternal parity | 1 (1, 1) | 1 (1, 3.2) | 0.04a |
| Maternal gravidity | 2 (1.2, 3) | 3 (2, 6) | 0.13 |
| Infant | |||
| Sex assigned at birth, n (%) | |||
| Male | 6 (43) | 9 (56) | 0.71 |
| Female | 8 (57) | 7 (44) | |
| Mode of delivery, n (%) | |||
| Vaginal | 2 (14) | 4 (25) | 0.17 |
| C-section | 12 (86) | 12 (75) | |
| Age (days) | |||
| Gestational age at birth | 197 ± 7 | 196 ± 8 | 0.80 |
| AGA at study time points | |||
| T1 | 204 ± 7 | 203 ± 8 | 0.70 |
| T2 | 214 ± 10 | 212 ± 8 | 0.61 |
| T3 | 231 ± 1 | 231 ± 1 | 0.51 |
| T4 | 244 ± 8 | 245 ± 1 | 0.41 |
| Weight (g) | |||
| Birth | 1,039 ± 131 | 1,016 ± 180 | 0.68 |
| T1 | 1,010 ± 142 | 999 ± 165 | 0.84 |
| T2 | 1,106 ± 130 | 1,114 ± 171 | 0.89 |
| T3 | 1,581 ± 197 | 1,555 ± 304 | 0.78 |
| T4 | 1,957 ± 216 | 1,920 ± 414 | 0.75 |
| Weight gain (since birth) | |||
| T1 | −29 ± 53 | −16 ± 65 | 0.55 |
| T2 | 67 ± 62 | 98 ± 71 | 0.21 |
| T3 | 542 ± 180 | 539 ± 207 | 0.97 |
| T4 | 918 ± 221 | 904 ± 330 | 0.89 |
| Weight for age Z score | |||
| Birth | −0.0 (−0.3, 0.5) | −0.0 (−0.6, 0.6) | 0.89 |
| T1 | −0.7 (−0.9, −0.3) | −0.6 (−1.1, −0.2) | 0.98 |
| T2 | −0.9 (−1.4, −0.5) | −0.9 (−1.3, −0.5) | 0.87 |
| T3 | −1.0 (−1.4, −0.5) | −0.9 (−1.8, −0.5) | 0.76 |
| T4 | −1.4 (−1.5, −0.9) | −1.4 (−2.2, −0.4) | 0.71 |
| Change in Z score (since birth) | |||
| T1 | −0.6 (−0.8, −0.4) | −0.6 (−0.7, −0.3) | 0.47 |
| T2 | −1.0 (−1.2, −0.7) | −0.8 (−1.1, −0.5) | 0.28 |
| T3 | −1.0 (−1.2, −0.6) | −1.0 (−1.3, −0.5) | 0.85 |
| T4 | −1.1 (−1.6, −0.7) | −1.3 (−1.7, −0.7) | 0.80 |
| Diet | |||
| Total enteral volume (since birth) | |||
| T1 | 67 ± 33 | 54 ± 33 | 0.27 |
| T2 | 128 ± 25 | 109 ± 40 | 0.12 |
| T3 | 174 ± 23 | 160 ± 41 | 0.25 |
| T4 | 206 ± 21 | 194 ± 45 | 0.34 |
| MOM proportion (% since birth) | |||
| % MOM (T1) | 79.3 (32.5, 100) | 100 (37.2, 100) | 0.54 |
| % MOM (T2) | 69.9 (26.9, 99.5) | 80.8 (46.2, 100) | 0.72 |
| % MOM (T3) | 57.2 (27.3, 94.2) | 63.9 (41.6, 95.4) | 0.69 |
| % MOM (T4) | 57.3 (17.9, 90.4) | 51.9 (36.4, 91.5) | 0.69 |
| Clinical | |||
| Received antibiotics | |||
| % days on antibiotics (total study duration) | 0 (0, 6.9) | 0 (0, 11.4) | 0.71 |
| T1–T2 | 0 (0, 0) | 0 (0, 15.7) | 0.12 |
| T1–T3 | 0 (0, 7.5) | 0 (0, 21.0) | 0.65 |
| T1–T4 | 0 (0, 6.9) | 0 (0, 11.4) | 0.71 |
| Prenatal (antenatal) steroids, n (%) | 12 (86) | 12 (75) | 0.66 |
| Received (postnatal) steroids, n (%) | 1 (8) | 2 (12) | 1.00 |
| Apgars 5-min score, median (IQR) | 7.5 (6.2, 8.0) | 8.0 (5.5, 9.0) | 0.46 |
| Total no. of days on ventilation, mean ± SD | 32.6 ± 23.3 | 29.6 ± 18.2 | 0.70 |
| Total no. of surfactant doses, median (IQR) | 1 (0.2, 2.0) | 1 (0, 1.2) | 0.42 |
| Need for oxygen support at 36 weeks, n (%) | 5 (36) | 4 (27) | 0.69 |
| Retinopathy, n (%) | 2 (14) | 5 (31) | 0.39 |
| Late-onset sepsis, n (%) | 2 (14) | 6 (37) | 0.25 |
Very low birth weight infants recruited into the study were randomized to receive standard bovine-derived human milk fortifiers (BHMF) or human-derived human milk fortifiers (H2MF) during the intervention period. Values are means ± SD or median (IQR) or n (%). Percentages reflect the proportion of non-missing data. Weight gain refers to weight at the study time point—birth weight. Weight-for-age Z scores were calculated using 2013 Fenton growth charts for preterm infants.25 Total enteral volume (TEV) is the cumulative average of TEV received by infants until a particular study time point from birth. % MOM volume is the average percentage of mother’s own milk (MOM) (proportion of MOM in the TEV used to prepare the feed prior to fortification) received by the infant until a particular study time point from birth. % days on antibiotics is the percentage of the number of days on antibiotics during total study duration or until a particular study time point. Nutritional support values indicate the proportion of infants from the particular group who received one of the other nutritional supports along with the human milk fortifiers during the study: liquid protein fortifier (LPF) 1–4 mL/100 mL; total parenteral nutrition (TPN), D10W, SMOF_Lipid 20, ECP (EnfaCare premature formula) 1 mg/100 mL; Nutramigen powder 2.5 mg. The p values are from Pearson’s chi-square test or Fisher’s exact test (for categorical variables) or t test or Wilcoxon sum rank test (for ordinal/numerical variables).
AGA, adjusted gestational age; MOM, mother’s own milk; T1, study day 0 (before fortification); T2, study day 7 (during fortification); T3, week 33 AGA (end of fortification); T4, week 35 AGA (follow-up after fortification).
p < 0.05