Active and passive smoking and the occurrence of natural menopause

We examined smoking in relation to natural menopause in 543 women who prospectively recorded menstrual data from their 20s. Mean age at natural menopause was 0.8 years younger (95% CL = -1.5, -0.0) in 98 women who smoked at menopause compared with 362 never-smokers (RR 1.3, 95% CI = 1.0-1.7). We did not observe a decrease in age at natural menopause in former smokers, a dose-response among current smokers, or a lower age at menopause with passive smoke exposure at home. These results suggest that the effect of smoking on ovarian senescence is limited to active smoking during the menopausal transition.