Background <p>As a neuro-psycho-social event, delivery can significantly impact maternal health. However, the association between childbirth and maternal bone health remains unclear, warranting further investigation.</p> Methods <p>Our study was based on data from the National Health and Nutrition Examination Survey (NHANES) (2005–2020). We employed propensity score matching, Welch’s two-sample t-test, linear mixed models, and partial correlation analysis to assess the relationship between delivery-related factors (parity, delivery mode, maternal age at delivery) and bone mineral density (BMD) of the lumbar spine and femoral neck.</p> Results <p>We obtained 5726 participants. Welch’s two-sample t-test showed that delivered subjects had lower mean BMD of the lumbar spine and femoral neck. The data from the linear mixed model showed a decrease in BMD of femoral neck and a decrease in BMD of lower spine in subjects who have delivered compared to those who had not. The same analyses showed lower BMD. Partial correlation analysis showed a negative correlation between age at delivery and BMD in women who gave delivery vaginally.</p> Conclusions <p>Parity and advanced maternal age at delivery are associated with decreased BMD. Notably, vaginal delivery is linked to reduced femoral neck BMD, a novel finding highlighting the potential biomechanical impact of this delivery mode.</p>