Associations of Birth Interval With Prevalence of Depression in Postmenopausal Women

<b>Background:</b> This study aims to explore the relationship between birth interval and prevalence of depression among postmenopausal women with two deliveries in the United States. <b>Methods:</b> Data from the National Health and Nutrition Examination Survey (NHANES) were used, which spanned the years 2005-2018 and is publicly accessible. We utilized weighted multivariable logistic regression analysis, restricted cubic splines (RCS), and subgroup analysis to examine the relationship between the prevalence of depression in postmenopausal women with only two deliveries and the age at first birth (AFB), age at last birth (ALB), and birth interval (the difference between ALB and AFB). <b>Results:</b> A total of 2375 postmenopausal women with only two deliveries were included in the study, and 271 (11.4%) had depression. RCS models showed that AFB and ALB were U-shaped curves associated with the prevalence of depression. Additionally, the birth interval was roughly L-shaped curve correlated with the risk of depression. <b>Conclusions:</b> Both early and late childbearing, as well as short birth intervals, may contribute to mental health challenges in this demographic. These findings suggest that women with both early and late childbearing, as well as those with short birth intervals, may face a higher risk of depression during their postmenopausal years. This underscores the importance of targeted mental health screening and support for these groups.