IN a new analysis of U.S. postmenopausal women, researchers have uncovered a striking U-shaped relationship between reproductive timing and osteoarthritis (OA) risk, suggesting that the spacing between childbirths and maternal age at delivery could influence long-term joint health. The study evaluated data from 3,088 women with two deliveries participating in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018.
Using multivariable logistic regression and restricted cubic spline models, the team found that OA prevalence in this group was 30.6%. The lowest OA risk was observed in women who had their first child at 24–25 years old, their last child at 25–30 years, and spaced their births 4–6 years apart. Outside of these ranges, OA prevalence increased, forming a U-shaped curve across each factor.
These associations held steady across a variety of subgroups, underscoring the potential physiological link between reproductive patterns and musculoskeletal aging. While causality cannot be confirmed in this cross-sectional design, the findings point toward the importance of considering reproductive history in OA risk stratification.
This study may contribute to future prevention strategies aimed at improving musculoskeletal health outcomes in postmenopausal women. As the population ages and OA remains a leading cause of disability, insights into non-traditional risk factors such as birth interval may prove clinically relevant.
Reference:
Chen L et al. The U-curve associations of birth interval with prevalence of osteoarthritis in postmenopausal women. Aging Clin Exp Res. 2025;37(1):144.
