Association of prepregnancy body mass index and prenatal depression in mothers: How is it affected by fathers?

Background: The link of prepregnancy body mass index (BMI) and postpartum depression is reported. Yet, little is known about the relationship between prepregnancy obesity and prenatal depression, while none investigates paternal effects. This study thus aims to examine the association between prepregnancy BMI and prenatal depression, with paternal effects of BMI and depression further investigated. Methods: A three-year prospective cohort study starting from 2010 is designed and implemented. A total of 112 mothers who undergo a first-trimester prenatal visit in selected hospitals are recruited for participation, together with their spouses. Parental self-reported prepregnancy weight and height, depressive symptoms from the Edinburgh Postnatal Depression Scale (EPDS), and sociodemographic traits are obtained three times from each trimester. Multivariate regression models are performed for analysis. Results: The prevalences of prenatal depression assessed by EPDS are 25%, 20%, 24%, and 31% in prepregnancy underweight, normal weight, overweight and obese women, respectively. After controlling for age, education, income, smoking status, marital status, chronic diseases, and lifestyle, underweight mothers are significantly more likely to have higher depressive symptoms than normal weight women (Adjusted odds ratio (AOR)=1.8, 95% confidence interval=1.4-2.3). Prepregnancy overweight (AOR=2.0) and obese (AOR=2.6) women are significantly more likely to report prenatal depression than normal weight women. The link was further affected by paternal BMI and depression level. Conclusions: This cohort study suggests an association between prepregnancy BMI and prenatal depression in mothers. This link is further affected by paternal BMI and depression, which emphasizes the critical role of fathers in maternal pregnancy.