Table 2. Bivariate analysis of risk factors for anemia in pregnant women in Nagpur, India, 2011–2013 (N = 12,782).

		Mild anemia		Moderate-to-severe anemia
Risk factor	Category	RRR	95% CI	RRR	95% CI
Fuel type	Clean fuel	1.00*		1.00*
	Biomass fuel	1.44	1.27–1.64 ‡	2.26	2.00–2.56 ‡
Age (years)	—	0.96	0.94–0.98 ‡	0.96	0.94–0.98 ‡
BMI (kg/m2)	—	0.92	0.90–0.94 ‡	0.83	0.81–0.85 ‡
Education	No formal schooling	1.00*		1.00*
	Primary	0.78	0.46–1.33	0.56	0.33–0.95 ‡
	Secondary	0.73	0.43–1.22	0.50	0.30–0.83 ‡
	University/ college	0.52	0.31–0.87 ‡	0.26	0.16–0.44 ‡
Exposure to household tobacco smoke	Never	1.00*		1.00*
	Less than monthly	1.29	1.09–1.52 ‡	1.68	1.43–1.98 ‡
	Monthly	1.24	0.96–1.59	1.24	0.96–1.59
	Weekly	1.46	1.06–2.01 ‡	1.31	0.95–1.81
	Daily	1.18	0.94–1.48	1.11	0.88–1.39
Parity (n)	0	1.00*		1.00*
	1	1.18	1.04–1.35 ‡	1.31	1.15–1.50 ‡
	2	1.40	1.09–1.79 ‡	1.86	1.46–2.37 ‡
	3+	1.69	0.97–2.92	3.53	2.08–6.00 ‡
Trimester	1st	1.00*		1.00*
	2nd	0.80	0.69–0.93 ‡	0.72	0.62–0.83 ‡
	3rd	0.81	0.68–0.96 ‡	0.50	0.42–0.59 ‡
Prenatal iron and folate supplements	Yes	1.00*		1.00*
	No	1.41	0.88–2.23	1.74	1.10–2.75 ‡

Mild anemia and moderate-to-severe anemia are defined as 10 g/dl ≤ hemoglobin (Hb) < 11 g/dl and Hb < 10 g/dl, respectively.

* Baseline category.

^‡ Differs significantly from 1 at the 95% confidence level.

Abbreviations: RRR = relative risk ratio, 95% CI = 95% confidence interval, BMI = body mass index.