Gestational weight gain and risk factors for postpartum depression symptoms from the Japan Environment and Children's Study: a prospective cohort study

Background : The relationship between postpartum depression symptoms (PPDS) and gestational weight gain is controversial. We aimed to examine the risk of gestational weight gain for PPDS at 1 month postpartum based on the pre-pregnancy body mass index (BMI). Methods : A prospective cohort study recruited 80 927 Japanese women 2011-2014. They categorized according to their pre-pregnancy BMI into group 1 ( Results : Among participants in group 3, insufficient gestational weight gain was a risk factor for PPDS (adjusted odds ratio: 1.24, 95% confidence interval: 1.14–1.36). This result was not modified by intermediate factors. Limitations : The criteria of appropriate gestational weight gain were determined from the adverse pregnancy outcomes not validated for PPDS. Other confounding factors for PPDS like psychotic disorders were not examined. Conclusions : For women with a pre-pregnancy BMI between 20.0 and