Table 3.

Percent mammographic density (least square means and 95% confidence intervals) by cumulative average consumption of alcohol prior to and after first full-term pregnancy^† among premenopausal women.

Alcohol intake	No. of women	Model 1‡	Model 2§
Prior to first pregnancy, g/day
0	187	41.6 (39.3, 44.0)	41.5 (37.7, 45.2)
>0 – <5	566	39.2 (37.9, 40.4)	39.0 (36.0, 41.9)
≥5 – <10	153	39.1 (36.7, 41.4)	38.6 (35.2, 41.9)
≥10	80	42.9 (39.5, 46.2)	42.4 (38.2, 46.6)
		Ptrend =0.40	Ptrend =0.50
After first pregnancy, g/day
0	218	40.3 (38.2, 42.4)	39.4 (35.8, 43.0)
>0 – <5	548	39.3 (38.1, 40.5)	38.9 (35.9, 41.8)
≥5 – <10	142	41.5 (39.0, 44.1)	40.9 (37.3, 44.6)
≥10	65	40.6 (36.9, 44.3)	39.4 (35.0, 43.8)
		Ptrend =0.36	Ptrend =0.49

^†Full-term pregnancy was defined as a pregnancy lasting at least six months.

^‡adjusted for age (continuous) and BMI (continuous) at mammogram

^§further adjusted for breast cancer in first-degree relative(s), benign breast disease, and use of oral contraceptives, all at or close to mammogram, as well as age at menarche, age at first pregnancy, and BMI at age 18