Pregestational overweight and obesity and symptoms of postpartum depression: Data from the Birth in Brazil Study

Relationship between pregestational overweight and obesity and symptoms of postpartum depression (PPD) has been documented in developed countries. In middle and low-income countries the studies are scarce and the pattern of findings is more mixed. Our objective is to assess the effect of pregestational overweight and obesity on development symptoms of PPD in a nationwide Brazilian study.

The study included 23,894 puerperal women, from 2011 to 2012. The Edinburgh Postnatal Depression Scale (EPDS) was applied from 6 to 18 months postpartum, with ≥13 points as the cutoff. Classification of pregestational nutritional status followed the method recommended by the Institute of Medicine. Confounding variables were identified using directed acyclic graph (DAG), and propensity score estimated the effect of nutritional status on PPD symptoms.

Prevalence of PPD was 26.3%. Women with excess weight represented nearly 32% of the sample. In the crude analysis, women with pregestational obesity showed 23% higher odds of developing symptoms of PPD when compared to those with normal weight (OR=1.23 CI 95% 1.04-1.45). There was a loss of statistical significance after propensity score analysis (OR=1.14 CI 95% 0.91-1.42).

The symptoms of PPD were measured in a single moment, and sensitivity analysis revealed the existence of omitted or non-measured variables potentially modifying these estimates.

Although we did not find a relationship between pregestational nutritional status and depressive symptoms, the results are important because of the problem's magnitude. Future studies should aim at a more comprehensive understanding of the complex relationship between the variables.