Table 4. Univariate and multivariate analyses for factors associated with all preterm, early and late preterm birth.

	Preterm Birth (24–36 weeks)				Early Preterm Birth (24–33 weeks)		Late Preterm Birth (34–36 weeks)
Study Characteristic	Univariate OR, 95% CI	p-value	Adjusted OR (95% CI)	p-value	Adjusted OR, (95% CI)	p-value	Adjusted OR, (95% CI)	p-value
Age <20	1.31 (1.02–1.69)	0.03	NS		1.73 (1.03–2.90)	0.04	NS
BMI	0.93 (0.89–0.98)	0.006	0.91 (0.85–0.97)	0.005	NS		0.91 (0.85–0.98)	0.01
BMI <18.5	1.63 (0.92–2.89)	0.09	NS		NS		NS
Weight Gain	0.90 (0.83–0.97)	0.008	0.89 (0.82–0.97)	0.006	NS		0.89 (0.80–0.96)	0.005
Ever Anemia (Hb<11.0)	1.44 (1.12–1.84)	0.001	NS		1.95 (1.08–3.52)	0.03	NS
Persistent Anemia (Hb<11.0 at booking visit and at 28–32 weeks )	1.36 (1.08–1.73)	0.99	NS		NS		NS
Ever Malaria	1.44 (1.12–1.84)	0.004	NS		NS		NS
Persistent Malaria (peripheral slide positive at booking and at 28–32 weeks)	1.75 (1.10–2.79)	0.04	1.94 (1.06–3.57)	0.03	NS		1.99 (1.05–3.79)	0.04
Previous Preterm birth	2.02 (1.27–3.22)	0.001	2.13 (1.19–3.80)	0.01	2.68 (1.10–6.52)	0.03	2.07 (1.11 – 3.86)	0.02
Previous Neonatal Death or Stillbirth	1.61 (1.05–2.49)	0.02	NS		NS		NS