Table 1.
Maternal and child characteristics in 748 children enrolled in this study, stratified by vaccination status.
| Population characteristicsa | Pre-vaccination children | Post-vaccination children | Pa,b |
|---|---|---|---|
| N | 400 | 348 | |
| Maternal age at delivery (years), M ± SD | 28.4 ± 6.0 | 28.2 ± 6.6 | 0.550 |
| Maternal race: non-Hispanic Black, n (%) | 217 (54.2) | 200 (57.5) | 0.417 |
| Maternal marriage status, married, n (%)c | 129 (32.2) | 115 (33.0) | 0.878 |
| Maternal education, < high school, n (%)c | 100 (25.0) | 102 (29.2) | 0.214 |
| Pre-pregnancy BMI category, n (%)c | 0.468 | ||
| Normal weight | 200 (50.0) | 182 (52.3) | |
| Overweight | 107 (26.8) | 98 (28.2) | |
| Obese | 93 (23.2) | 68 (19.5) | |
| Parity, nulliparous, n (%) | 141 (35.2) | 164 (47.1) | 0.001 |
| Maternal ever smoking during pregnancy, n (%)c | 76 (19.0) | 53 (15.2) | 0.206 |
| Maternal Mediterranean-Style Diet score, M ± SD | 24.5 ± 4.0 | 25.0 ± 4.0 | 0.117 |
| Gestational age (weeks), Median (IQR) | 39.0 (37.6–39.9) | 39.2 (37.6–40.3) | 0.097b |
| Preterm birth (< 37 weeks), n (%) | 68 (17.0) | 60 (16.9) | 1.000 |
| Mode of delivery, cesarean section, n (%) | 145 (35.6) | 127 (35.9) | 1.000 |
| Child’s sex, male, n (%) | 193 (48.2) | 168 (48.3) | 1.000 |
| Feeding modality: exclusively formula-fed, n (%)c | 103 (25.8) | 72 (20.7) | 0.123 |
| Child’s age at IgG profiling (years), Median (IQR) | 0.82 (0.76–0.95) | 2.3 (1.68–3.20) | <0.001b |
IQR: Inter-quartile range.
a,b
The differences in population characteristics between pre-vaccination and post-vaccination children were compared using the t-test for continuous variables (or b the Kruskal-Wallis Rank Sum test for continuous variables with non-normal distribution), and the chi square test for categorical variables, respectively.
c
These categorical variables have missing data in < 5 % samples (see Table S1) and were imputed as the most-frequent category.