Having two children might be best for women's mental health: Evidence from UK Biobank

Background

Limited research has examined the association between the number of live births and bipolar disorder and major depression (BDMD). This study aims to investigate the relationship between the number of live births and BDMD among women in the UK, providing a theoretical basis for reproductive decision-making.

Methods

This cross-sectional study utilized data from >55,000 women in the UK Biobank. Inverse probability treatment weighting (IPTW) logistic regression models were employed to reduce bias and confounding. Multivariate logistic regression was applied to examine the relationship between live births and BDMD, while restricted cubic spline regression was utilized to analyze the nonlinear association between the number of live births and BDMD. Subgroup analyses were conducted, stratifying by age, BMI, spontaneous abortion, induced abortion, and spontaneous abortion.

Results

The IPTW-multivariate logistic regression analysis indicated that live births serve as an independent protective factor against BDMD. In IPTW-multivariate Model 4, the odds ratio (OR) for the live births group was 0.71 (95 % CI 0.69–0.73, P < 0.001). A significant nonlinear relationship was identified between the number of live births and the risk of BDMD. Additionally, it was found that women with two live births exhibited the lowest risk of BDMD.

Conclusion

Our study demonstrated that live births are an independent protective factor against BDMD. This research holds particular significance in the context of globally declining fertility rates and the increasing prevalence of mental disorders. It provides guidance for women on fertility decisions amid declining global fertility rates and increasing mental health issues.