Table 1.
Characteristics of mother-infant dyads from the Southern California mother’s milk study at 1-month of infant age
| Overall (n = 132) |
Rapid Growth (n = 54) |
Non-Rapid Growth (n = 78) |
Crude OR (95% CI) |
Crude OR p-value |
|
|---|---|---|---|---|---|
| Maternal Characteristics | |||||
| Age at Infant Birth (years) | 29.5 ± 6.3 | 29.3 ± 6.2 | 29.7 ± 6.4 | 0.99 (0.94,1.0) | 0.72 |
| Pre-Pregnancy BMI (kg/m2) | 28.4 ± 5.7 | 28.7 ± 5.4 | 28.1 ± 6.0 | 1.0 (0.96, 1.1) | 0.51 |
| Delivery (vaginala, cesarian, %vaginal) | 98, 34, 74.2% | 38, 16, 70.4% | 60, 18, 76.9% | 1.4 (0.64, 3.1) | 0.40 |
| SES Indexb | 26.9 ± 12.2 | 26.2 ± 11.7 | 27.3 ± 12.6 | 0.99 (0.96, 1.0) | 0.61 |
| Pre-Pregnancy Weight Status | |||||
| Normal Weight | 37, 28.0% | 12, 22.2% | 25, 32.1% | Ref | Ref |
| Overweight | 50, 37.9% | 22, 40.7% | 28, 35.9% | 1.6 (0.68, 4.0) | 0.28 |
| Obese | 45, 34.1% | 20, 37.0% | 25, 32.1% | 1.7 (0.67, 4.2) | 0.27 |
| Weight Status at 1-Month Postpartum | |||||
| Normal Weight | 23, 17.4% | 7, 13.0% | 16, 20.5% | Ref | Ref |
| Overweight | 48, 36.4% | 20, 37.0% | 28, 35.9% | 1.6 (0.58, 4.9) | 0.36 |
| Obese | 61, 46.2% | 27, 50.0% | 34, 43.6% | 1.8 (0.67, 5.3) | 0.25 |
| Maternal Dietary Measures at 1-Month | |||||
| Total energy intake (kcals) | 1724.9 ± 534.73 | 1682.7 ± 404.06 | 1761.8 ± 609.9 | 1.00 (1.00, 1.00) | 0.45 |
| Fat intake (g) | 58.55 ± 23.09 | 56.918 ± 19.272 | 59.687 ± 25.462 | 0.99 (0.98, 1.01) | 0.50 |
| Protein intake (g) | 76.487 ± 23.305 | 74.555 ± 17.79 | 77.825 ± 26.288 | 0.99 (0.98, 1.01) | 0.42 |
| Carbohydrate intake (g) | 229.5 ± 81.701 | 223.17 ± 66.787 | 233.89 ± 91.299 | 1.00 (0.99, 1.00) | 0.45 |
| Infant Characteristics | |||||
| Age (days) | 32.8 ± 5.2 | 33.4 ± 5.3 | 32.4 ± 5.2 | 1.0 (0.97, 1.1) | 0.28 |
| Infant Sex (femalea, male, %female) | 72, 60, 54.5% | 30, 24, 55.6% | 42, 36, 53.8% | 0.93 (0.46, 1.9) | 0.84 |
| Delivery | |||||
| On-Time (n, %)a | 64, 48.5% | 26, 48.1% | 38, 48.7%* | Ref | Ref |
| Late (n, %) | 36, 27.3% | 9, 16.7% | 27, 34.6% | 0.49 (0.19, 1.2) | 0.12 |
| Early (n, %) | 32, 24.2% | 19, 35.2% | 13, 16.7% | 2.1 (0.91, 5.2) | 0.08 |
| Birth Weight (kg) | 3.4 ± 0.42 | 3.1 ± 0.36 | 3.6 ± 0.37*** | 0.03 (0.006, 0.10) | <0.001 |
| Birth Length (cm) | 50.5 ± 2.4 | 49.7 ± 2.3 | 51.1 ± 2.3*** | 0.76 (0.63, 0.89) | 0.001 |
| Weight (kg) | 4.6 ± 0.49 | 4.5 ± 0.48 | 4.7 ± 0.48** | 0.36 (0.16, 0.75) | 0.008 |
| Length (cm) | 54.2 ± 1.8 | 53.6 ± 1.8 | 54.6 ± 1.8** | 0.74 (0.59, 0.90) | 0.004 |
| Weight for Length z-Score | 0.65 ± 1.3 | 0.70 ± 1.4 | 0.62 ± 1.3 | 1.0 (0.81, 1.4) | 0.73 |
| Body Mass Index z-Score | 0.59 ± 1.1 | 0.47 ± 1.1 | 0.67 ± 1.1 | 0.84 (0.60, 1.2) | 0.29 |
| Antibiotics at 1-month (noa/yes, %yes)c | 116, 15, 11.5% | 47, 7, 13.0% | 69, 8, 10.4% | 1.28 (0.42, 3.81) | 0.65 |
| Infant Dietary Measures | |||||
| Breast Feedings/Day (≥8a, <8, % ≥8) | 97, 35, 73.5% | 37, 17, 68.5% | 60, 18, 76.9% | 1.5 (0.70, 3.4) | 0.28 |
| Formula Feeding/Day (yes/noa) | 51, 81, 38.6% | 18, 36, 33.3% | 33, 45, 42.3% | 1.5 (0.72, 3.1) | 0.30 |
| Age of Solid Food Introduction (months) | 5.8 ± 1.5 | 5.7 ± 1.3 | 5.8 ± 1.6 | 0.93 (0.72, 1.2) | 0.56 |
Table 1. Baseline (1-month) characteristics of 132 Hispanic mother-infant dyads from the Southern California Mother’s Milk Study. Pre-pregnancy BMI, infant sex, birth weight and birth length are also shown. Data are reported mean and standard deviation (SD) unless otherwise noted. Logistic regression was used to determine the crude odds ratio (OR) and 95% confidence intervals (CIs) for each baseline variable and rapid infant growth from birth to 12-months of age where the areference group is indicated. Total samples sizes include bn = 130 for the Hollingshead Four Factor Index as a measure of socioeconomic status (SES) (rapid n = 53 and non-rapid n = 77) and cn = 131 for infant antibiotic exposure in the first month of life. For continuous variables, independent parametric or non-parametric t-tests were used to test for differences between infants with rapid and non-rapid growth. For categorical variables, chi-square tests were used to test for differences between infants with rapid and non-rapid growth. Statistical significance between rapid and non-rapid growers corresponds to ***p < 0.001, **p < 0.01, and *p < 0.05.