The relationship between parity, delivery mode, maternal age at delivery, and bone mineral density: a cross-sectional study.

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.