Associations between reproductive factors and frailty in middle-aged and older women: Evidence from the China Health and Retirement Longitudinal Study

BACKGROUND The study was based on data from CHARLS, a national longitudinal health survey of residents aged 45 years and older in mainland China. METHODS Frailty is assessed by the Frailty Index (FI), constructed based on 50 indicators of health deficits. Reproductive factors were extracted from the CHARLS survey. They included the number of biological children, age at menopause, age at menarche, age at first birth, reproductive period, and history of abortion. RESULTS We found that participants with ≥ 3 children had a 26.6% increased risk of frailty compared with participants with 2 children, and those with menarche aged 18 years or older had a 30.1% increased probability of frailty compared with participants with menarche aged 15 years or younger. Participants with menopause at age 55 or older were 57.4 percent more likely to be frail compared to those with menopause between 45 and 55 years of age. In addition, women with a history of abortion were significantly associated with an increased prevalence of frailty, with reproductive period ≤ 33 being a protective factor. The age of the first livebirth did not exhibit a significant association with frailty. CONCLUSIONS The findings suggest that the risk of developing frailty among middle-aged and older Chinese women is strongly associated with specific reproductive factors, such as the number of biological children, age at menarche, history of abortion, and age at menopause. These findings provide potential reproductive health indicators for early identification and prevention of frailty and highlight the importance of further research into these relationships.