Table 3.

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.