Work-related factors associated with age at natural menopause in a generation of French gainfully employed women.

This study's purpose was to identify occupational factors that may influence the age at natural menopause in a random sample of gainfully employed French women born in 1938 (n=1,594). Occupational physicians selected the subjects from their files and interviewed them during their annual visits in 1990 and 1995. The authors used Kaplan-Meier survival curves to estimate median age at menopause (52 years) and multiple Cox models to estimate associations among women's characteristics, occupational factors, and age at menopause separately within two strata distinguished by a self-reported history of depression. Among women without such a history, earlier menopause was associated with smoking more than 10 cigarettes per day in 1990 (p<0.001), a high-strain job (p=0.01) in 1990, and difficult schedules before 1990 (p=0.03). Later menopause was associated with higher educational status (p=0.003) and repetitive work in 1990 (p=0.005). Among women with a history of depression, a later menopause was associated with having at least one child (p<0.001) and menarche later than the age of 13 years (p=0.004). Earlier menopause was associated with a high job control in 1990 (p=0.03) and high school education (p<0.01). These results suggest that certain physical job stressors may be related to age at menopause.