Prepregnancy Obesity and a Biobehavioral Predictive Model for Postpartum Depression

Abstract Objective To test a predictive model of the associations among prepregnancy body mass index (BMI), third-trimester biological and behavioral variables, and symptoms of depression at 4 weeks postpartum. Design Secondary data analysis from a longitudinal, biobehavioral repeated-measures study of women during the third trimester of pregnancy through 6 months postpartum. Setting Communities surrounding a Midwestern and a Western U.S. city. Participants Participants were 111 women enrolled during their third trimesters of pregnancy who were studied through 4 weeks postpartum. Methods Whole blood and saliva were used for biological measures, and validated questionnaires were used for behavioral measures. Principal component analysis and path analysis with principal component variables were used to iteratively test the model. Results There were three statistically significant direct effects in the model: the path from prepregnancy BMI to inflammation, the path from prepregnancy BMI to stress, and the path from stress to symptoms of depression at 4 weeks postpartum. Indirect effects of prepregnancy BMI on postpartum depression through intervening variables were not statistically significant, nor was the model-based total effect of prepregnancy BMI on postpartum depression. Conclusion Stress was significantly linked to prepregnancy BMI and postpartum depression. This finding highlights continuing possibilities for improving outcomes for mothers, infants, and families through stress-mitigating preventive strategies.