RISK FACTORS FOR EARLY NATURAL MENOPAUSE: EVIDENCE FROM THE 1958 AND 1970 BRITISH BIRTH COHORTS
Using data from two generations of British women followed from birth through childhood and into adulthood, we investigate risk factors for the onset of natural menopause before the age of 45 (known as early menopause). We focus on key stages during the life course to understand when risk factors are particularly harmful. We find that earlier cessation of menstruation is influenced by circumstances at birth. Women born in lower social class families, whose mother smoked during the pregnancy or who were short-term breastfed (one month or less) were more likely to undergo menopause before 45. Early menopause is also associated with poorer cognitive ability and smoking in childhood. Adult health behaviour also matters. Smoking is positively correlated with early menopause, while regular exercise (one to several times a week) and moderate frequency of alcohol drinking (one to three times a month) in women's early thirties are associated with a reduced risk of early menopause. The occurrence of gynaecological problems by women's early thirties is also linked to early menopause. We note that some of these factors (e.g. health behaviours) are modifiable and thus the risks may be preventable.