Table 2.

Logistic regression analysis for LBW and its determinants

	Crude ORs	Adjusted ORs *
	OR (95% CI)	OR (95% CI)
Maternal age (at child birth)	0.96 (0.94–0.99)	0.96 (0.92–1.00)
Maternal education
University	1.0 (ref.)	1.0 (ref.)
Illiterate and primary	3.87 (0.93–16.00)	3.32 (0.79–13.94)
Secondary and high school	4.29 (1.05–17.54)	3.44 (0.83–14.25)
Number of parities	0.98 (0.86–1.12)	1.01 (0.85–1.20)
History of LBW deliveries
No	1.0 (ref.)	1.0 (ref.)
Yes	1.94 (1.07–3.51)	2.53 (1.06–6.03)
History of pre term labor
No	1.0 (ref.)	1.0 (ref.)
Yes	1.41 (0.70–2.84)	0.65 (0.23–1.81)
Cigarette smoking
No	1.0 (ref.)	1.0 (ref.)
Yes	3.74 (1.63–8.54)	4.64 (1.97–10.95)
Chronic diseases
None	1.0 (ref.)	1.0 (ref.)
Hypertension	3.11 (1.93–5.02)	3.70 (2.25–6.06)
Others	1.91 (1.03–3.53)	2.04 (1.09–3.83)
Residence
Tehran	1.0 (ref.)	1.0 (ref.)
Suburbs of Tehran	1.41 (1.04–1.92)	1.24 (0.90–1.71)

* Adjusted for all variables studied in one model.