Table 2: Unadjusted and adjusted analyses showing associations between factors in first and second births and odds of not initiating breastfeeding in the second birth among women who did initiate breastfeeding in the first birth

Factor	Birth 1	Birth 2	Unadjusted OR (95% CI)	Adjusted OR* (95% CI)
Smoking	No	No	1.00	1.00
	No	Yes	2.91 (1.89-4.39)	1.61 (1.03-2.52)
	Yes	No	1.54 (1.01-2.30)	1.02 (0.67-1.57)
	Yes	Yes	3.13 (2.46-3.96)	1.58 (1.21-2.08)
High-income area	Yes	Yes	1.00	1.00
	Yes	No	1.50 (1.03-2.14)	0.99 (0.67-1.45)
	No	Yes	1.26 (0.87-1.79)	1.54 (1.12-2.12)
	No	No	1.87 (1.53-2.28)	1.44 (1.17-1.78)
Cesarean delivery	No	No	1.00	1.00
	No	Yes	1.35 (0.90-1.97)	1.30 (0.96-1.77)
	Yes	No	0.46 (0.24-0.80)	0.57 (0.31-1.05)
	Yes	Yes	1.33 (1.08-1.64)	1.70 (1.36-2.13)
Folic acid	Yes	Yes	1.00	1.00
	Yes	No	1.68 (1.24-2.26)	1.30 (0.96-1.77)
	No	Yes	1.44 (1.05-1.97)	0.99 (0.71-1.38)
	No	No	3.57 (2.86-4.48)	1.78 (1.36-2.33)
Tertiary hospital type	Yes	Yes	1.00	1.00
	Yes	No	3.16 (2.01-4.85)	2.34 (1.47-3.72)
	No	Yes	0.80 (0.28-1.87)	0.53 (0.22-1.44)
	No	No	2.03 (1.69-2.45)	1.54 (1.26-1.87)
Recreational drug use	No	No	1.00	1.00
	No	Yes	0.61 (0.15-1.77)	0.22 (0.07-0.73)
	Yes	No	2.33 (1.21-4.24)	1.24 (0.64-2.38)
	Yes	Yes	4.73 (1.76-11.8)	2.29 (0.87-6.05)
Maternal age in birth 2 (continuous), yr	-	-	0.88 (0.87-0.90)	0.92 (0.90-0.95)

Note: CI = confidence interval, OR = odds ratio.

*Adjusted for other factors in table; both adjusted and unadjusted analyses include only observations with nonmissing values for each factor.