Relation between smoking and age of natural menopause. Report from the Boston Collaborative Drug Surveillance Program, Boston University Medical Center.

The relation of cigarette smoking to natural menopause has been evaluated in two independent sets of data. In both, at each age from 44 to 53 years, more current smokers were post-menopausal compared to "never" smokers. In the first set of data the age-standardised proportions of women who were postmenopausal were 35, 36, 43, and 49%, respectively, for never smokers, ex-smokers, and current smokers of 1/2 and greater than or equal to 1 pack per day. The corresponding proportions for the second set were 53, 59, 60 and 65%.