Time Since Prior Tetanus-Containing Vaccination, y
Outcome	<2	2–5	>5 (Control)
Local reactions, rate/10 000 women	4.2	7.0	11.2
Adjusted risk ratio (95% CI)	0.49 (0.11–2.20)	0.77 (0.31–1.95)	1 [Reference]
P value	.35	.59
Preterm delivery, %	6.6	6.4	6.8
Adjusted risk ratio (95% CI)	1.15 (0.98–1.34)	1.06 (0.94–1.19)	1 [Reference]
P value	.08	.33
Small for gestational age, %	9.0	8.7	9.1
Adjusted risk ratio (95% CI)	0.99 (0.87–1.13)	0.96 (0.87–1.06)	1 [Reference]
P value	.88	.45