Table 3.

Relative risks (RRs) for the joint effect of parity and breastfeeding

Parity (n)		Breastfeeding (mo)
Category	RR1,2		0	<6	6-12	≥13
		RR1,2	1.00	0.79	0.72	0.67
0	1.00	Joint RR	1.0
1	0.72		0.7	0.6	0.5	0.5
2	0.57		0.6	0.5	0.4	0.4
≥3	0.46		0.5	0.4	0.3	0.3

¹The RRs in each category were estimated using a random effect model.

²We used the summary RR from the analysis of 32 studies with parity categories of 1, 2, and ≥3 and 15 studies with breastfeeding categories of <6, 6-12, and ≥13 months (as shown in Table 1).