Table 4.
Multivariate analyses for the difference in rate of weight change (adjusted for paired height)
| Rate differences | 95% CI | Difference in weight, birth to 5 years | Transformed to body mass index (BMI) | ||||
|---|---|---|---|---|---|---|---|
| Weight gain (kg) | Absolute weight difference (kg) | 95% CI | Absolute BMI difference (kg/m2) | 95% CI | |||
| Vaginal Cohort – Main Model | |||||||
| GBS IAP vs. No antibiotics | 1.44% | 0.3%, 2.6% | 16.62 | 0.24 | 0.04, 0.44 | 0.20 | 0.04, 0.36 |
| Other antibiotics vs. No antibiotics | 1.18% | −0.1%, 2.5% | 16.62 | 0.20 | −0.01, 0.41 | 0.16 | −0.01, 0.34 |
| Cesarean Cohort – Main Model | |||||||
| GBS IAP vs Other antibiotics | 3.52% | 1.9%, 5.2% | 17.06 | 0.60 | 0.32, 0.88 | 0.50 | 0.26, 0.73 |
| Vaginal Cohort – Model excluding pediatric antibiotics | |||||||
| GBS IAP vs. No antibiotics | 1.44% | 0.3%, 2.6% | 16.45 | 0.24 | 0.04, 0.43 | 0.20 | 0.03, 0.36 |
| Other antibiotics vs. No antibiotics | 1.16% | −0.1%, 2.4% | 16.45 | 0.19 | −0.02, 0.40 | 0.16 | −0.02, 0.33 |
| Cesarean Cohort – Model excluding pediatric antibiotics | |||||||
| GBS IAP vs. Other antibiotics | 3.53% | 1.9%, 5.2% | 16.83 | 0.59 | 0.32, 0.87 | 0.49 | 0.26, 0.72 |
| Vaginal Cohort – Model excluding pediatric antibiotics and breastfeeding | |||||||
| GBS IAP vs. No antibiotics | 1.48% | 0.3%, 2.7% | 16.31 | 0.24 | 0.05, 0.44 | 0.20 | 0.04, 0.36 |
| Other antibiotics vs. No antibiotics | 1.18% | −0.1%, 2.5% | 16.31 | 0.19 | −0.02, 0.40 | 0.16 | −0.01, 0.33 |
| Cesarean Cohort – Model excluding pediatric antibiotics and breastfeeding | |||||||
| GBS IAP vs. Other antibiotics | 3.56% | 1.9%, 5.2% | 16.72 | 0.60 | 0.32, 0.87 | 0.49 | 0.26, 0.72 |
Multivariate model adjusted for: maternal race/ethnicity (Black/Non-Hispanic, White/Non-Hispanic, Asian, Hispanic, Unknown/Other), maternal weight, maternal height, parity (1, 2, 3, 4 and above), maternal GBS colonization status (positive, negative, unknown), maternal chorioamnionitis, percent Black and poverty ratio by residential address (per 10%), birth year and month (categorical), birth weight z-score (continuous), infant sex, insurance (Medicaid vs. private/unknown), pediatric center (academic vs non-academic); breastfeeding at 3 months, neonatal antibiotics (administered <72 hours after birth), pediatric antibiotics (0, 1, 2–4, 5–10, ≥11 prescriptions) and chronic antibiotic courses (0, 1, ≥2). Rate difference and confidence limits obtained from the final model were multiplied with the estimated weight and height gain of the reference group in each delivery mode strata to generate the expected absolute weight and BMI differences at 5 years between the exposed and the unexposed infants. BMI, body mass index; CI, confidence interval; GBS, group B Streptococcus; IAP, intrapartum antibiotic prophylaxis; vs, versus.