Prospective Study on the Risks of Dengue Fever for the Fetus.

Dengue is the most common arbovirus worldwide (390 million people infected each year) and belongs to the Flavivirus genus of the Flaviviridae family like Zika. Its expansion has been rapid since the last decade with an increase in the number of cases of 400% and the first cases of indigenous dengue described in Europe. Current data on the consequences of dengue fever on the fetus are incomplete. The risk of maternal-fetal transmission of dengue during the peripartum period has now been recorded in numerous case reports and a few case series for patients who contracted dengue in the 12 days preceding childbirth or at the time of delivery. However, the transmission of dengue is highly variable depending on the studies ranging from 1.6 to 15% and the consequences for the newborn are very variable ranging from simple thrombocytopenia to death in severe neonatal dengue. Regarding the risk of malformation, a few old cases of heart disease, hydrocephalus and neural tube closure abnormalities have been described in the literature following exposure to dengue fever during pregnancy. Since no malformative case has been described, however, to our knowledge, no prospective study with specialized ultrasound monitoring has been performed for pregnant women who contracted dengue during their pregnancy.