Table 5 Association of breast cancer and reproductive factors by hormone receptor status.

Age at menarche (years)

1.02

(0.87–1.19)

0.84

0.63

(0.45–0.89)

0.01

0.67

(0.46–0.98)

0.04

Pregnancy ever

0.35

(0.13–0.96)

0.04

1.12

(0.22–5.72)

0.89

0.53

(0.07–3.91)

0.53

Age at FFTP (years)^c

1.11

(1.04–1.19)

0.003

1.03

(0.91–1.17)

0.61

0.97

(0.84–1.13)

0.71

Time between menarche and FFTP (years)^c

1.12

(1.04–1.20)

0.002

1.10

(0.97–1.26)

0.15

1.06

(0.91–1.23)

0.49

Age at last pregnancy (years)^c

1.10

(1.02–1.19)

0.01

1.08

(0.94–1.25)

0.29

1.05

(0.89–1.24)

0.55

Time since last birth (years)^c

0.92

(0.85–0.99)

0.02

0.95

(0.83–1.09)

0.44

0.99

(0.84–1.16)

0.88

Parity^d

0.64

(0.47–0.87)

0.005

0.93

(0.54–1.58)

0.78

0.99

(0.51–1.92)

0.98

Breastfeeding ever^c

0.23

(0.09–0.58)

0.002

1.57

(0.46–5.43)

0.47

0.84

(0.21–3.36)

0.80

Duration of breastfeeding (months)^c

0.99

(0.98–1.01)

0.48

0.97

(0.93–1.01)

0.13

0.97

(0.92–1.02)

0.20