Dengue represents a major worldwide public health problem. According to the WHO, up to 50 million dengue infections occur each year. The occurrence of dengue fever and dengue hemorrhagic fever has increased in Brazil, in part due to the simultaneous circulation of DENV-1, DENV-2 and DENV-3. Although a primary infection with one serotype confers a partial or transient immunity against other serotypes, any subsequent infections harbor the risk of increased morbidity/mortality. Several case reports have been published regarding maternal and fetal outcomes from dengue infection, but it is still inconclusive if pregnancy is associated with severity. To estimate the severity of maternal dengue infection, available data that were compiled from 2007 to 2008 by the official surveillance information system of the city of Rio de Janeiro were reviewed. The cases of dengue were analyzed using the 1997 WHO classification. Pregnant women were 3.4 times more prone to developing severe dengue than non-pregnant women. Mortality among pregnant women was superior to non-pregnant women. The increased risk of severe outcomes in pregnant women merits further attention to effective public health and medical interventions that will aid in avoiding morbidity/fatalities within this population.