Background The increasing number of dengue cases worldwide implies a greater exposure of at-risk groups, such as pregnant women. DENV infection during pregnancy has been increasingly associated with unfavorable outcomes, but the evolution of the disease and its clinical outcomes remain unclear. The objective of this study was to characterize dengue cases in reproductive aged women by comparing the development of the disease in pregnant and non-pregnant women. Methods A population based retrospective cohort study that used data reported in the Brazilian Mandatory Notifiable Diseases Information System from 2016 to 2019 in Paraná, Brazil. We compared sociodemographic, clinical, and laboratory variables between pregnant and non-pregnant women. Hospitalization and disease severity classification (Dengue, Dengue with warning signs, Severe Dengue) were considered outcome variables. Results The two groups had differences in the year of notification, age distribution, and region of residence. Laboratory investigation was more frequent among pregnant women, and DENV-2 prevailed in both groups. The risks of hospitalization and development of Severe Dengue were higher in pregnant women. There were no deaths observed among pregnant women. Conclusion This study identified pregnancy as a risk factor for an increase in the severity of DENV infection. It reinforces the importance of identifying early signs of complication, close monitoring, and adequate treatment for pregnant women.