Contracting a dengue infection during pregnancy could negatively impact the health of the unborn child during the early years of life, a new study has revealed.

Dengue fever, one of the most prevalent mosquito-borne diseases globally, threatens the lives of half of the world's population. Over recent years, there has been a dramatic rise in cases, with more than three million cases reported in the Americas in 2023 alone.

"Even though dengue is a very common mosquito-borne disease, there has not been much attention given to the impact it has on birth outcomes and as a result, what can be done to improve them and protect pregnant women and their children," Dr. Livia Menezes, co-author of the study, from the University of Birmingham, said in a news release.

To examine the impact of maternal dengue infections on birth outcomes, researchers used a large data set of dengue fever infections in expectant mothers from Minas Gerais, Brazil. They found out that children whose mothers contracted dengue fever during pregnancy faced a 27% higher likelihood of hospitalization from birth to age three. The risk peaks during the second year, with a 76% increase in hospitalization rates, according to the study published in the American Economic Journal: Applied Economics.

"This paper sets out robust research which shows that being infected with dengue fever, even with a mild case, whilst pregnant can have a significant impact on the health of the child once born. These birth outcomes can even have longer-term impacts, for example, previous research has shown that low birth weight can negatively affect socio-economic outcomes and health in adulthood," Dr. Menezes said.

The analysis also showed that infants born to mothers who contracted dengue fever during pregnancy had reduced birth weights. This raised the risk of newborns being categorized as having very low birth weight by 67% and extremely low birth weight by 133%.

"These negative birth outcomes are not only limited to the health of individual children and mothers, but they have a much wider impact on communities where dengue fever is common. Hospitalizations and ongoing health issues resulting from maternal infections all have a cost, and one that could be avoided, or at least minimized with increased awareness and improved policy," said another co-author, Dr. Martin Foureaux Koppensteiner, Associate Professor in Economics at the University of Surrey.

"We strongly suggest that dengue fever should be considered alongside the TORCH infections to manage and avoid when pregnant, which currently include Toxoplasmosis, Rubella, HIV, syphilis, chicken pox, Zika, and influenza among others," said Dr. Koppensteiner.

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