Maternal age at first birth and uterine cancer risk: A comprehensive analysis using NHANES data (2003-2018)

Several reproductive factors, including parity and age at menarche, have been identified as risk factors for uterine cancers. However, the association between maternal age at first birth and uterine cancer remains conflicting.

This cross-sectional study included females aged 20 years and older with at least one live birth across eight National Health and Nutrition Examination Survey (NHANES) cycles (2003-2018). We used design-adjusted logistic regression, with multiple imputation for missing data, to explore the association of age at first birth and uterine cancer. As a sensitivity analysis, the sample was restricted to post-menopausal females; logistic regression analyses were repeated.

Among 7095 participants, 104 had uterine cancer. The adjusted odds ratio (aOR) for uterine cancer for participants with a first live birth at ≥25 years was 0.66 (95 % confidence interval (CI): 0.33-1.35) compared to those with a first birth at <20 years. For participants with a first birth between 20-24 years, the aOR was 0.93 (95 % CI: 0.51-1.69). Multiple imputation and sensitivity analyses yielded similar non-significant results.

Our findings suggest no statistically significant association between maternal age at first live birth and uterine cancer, aligning with existing literature. Further research is needed to explore other reproductive factors and their role in uterine cancer risk.