Factors associated with adequate levels of protective antitetanus antibodies among newborns
| Variable | Crude PR | Adjusted PR | 95% CI | P value |
| Maternal TT antibodies (IU/mL) | ||||
| <0.1 | 1 | 1 | ||
| ≥0.1 | 3.3 (1.6–7.0) | 3.1 | 1.5 to 6.4 | 0.002 |
| Gestation at first ANC visit | ||||
| ≤12 weeks | 1 | 1 | ||
| >12 weeks | 1.3 (1.0–1.6) | 1.2 | 1.0 to 1.5 | 0.030 |
| Gestation at last TD dose | ||||
| <28 weeks | 1 | 1 | ||
| ≥28 weeks | 1.3 (1.1–1.5) | 1.1 | 1.0 to 1.3 | 0.034 |
| TT/TD doses before current pregnancy | ||||
| <5 doses | 1 | 1 | ||
| ≥5 doses | 0.94 (0.84–1.1) | 0.94 | 0.85 to 1.0 | 0.244 |
| TT/TD doses during current pregnancy | ||||
| 0–1 | 1 | 1 | ||
| 2 | 1.2 (1.1–1.3) | 1.1 | 1.0 to 1.2 | 0.025 |
| 3–4 | 1.3 (1.2–1.4) | 1.1 | 1.0 to 1.2 | 0.004 |
| Maternal age (years) | ||||
| ≤20 | 1 | 1 | ||
| 21–30 | 1.1 (0.97–1.3) | 1.1 | 0.95 to 1.2 | 0.259 |
| >30 | 1.0 (0.88–1.2) | 1.0 | 0.86 to 1.2 | 0.865 |
| Birth weight (kg) | ||||
| ≥2.5 | 1 | 1 | ||
| <2.5 | 0.80 (0.66–0.97) | 0.86 | 0.74 to 1.0 | 0.059 |
| HIV | ||||
| No | 1 | 1 | ||
| Yes | 0.94 (0.80–1.1) | 1.0 | 0.92 to 1.17 | 0.555 |
| High blood pressure (>140/90 mm Hg) | ||||
| No | 1 | 1 | ||
| Yes | 1.0 (0.85–1.2) | 1.0 | 0.92 to 1.2 | 0.608 |
| Febrile (>37.5°C) | ||||
| No | 1 | 1 | ||
| Yes | 1.0 (0.91–1.1) | 1.0 | 0.91 to 1.1 | 0.936 |
ANC, antenatal care; PR, prevalence ratio; TD, tetanus diphtheria; TT, tetanus toxoid.