Forest plot of OR and 95% CI for parent estrogens. The center mark on each line corresponds to the odds ratio (OR) estimate and the length of the line corresponds to the confidence interval. Quartile cutpoints are based on the control distribution. For the referent quartile, only a mark at 1.0 is presented. ORs are adjusted for family history of breast cancer; BMI; age at menarche; parity and age at first birth; age at blood collection; type of menopause; years between blood collection and menopause; and time of day of blood draw. BMI, body mass index.