Assessing Dengue Virus Infection During Pregnancy: Prevalence and Impact on Maternal and Child Outcomes

Dengue virus (DENV) is the most common arbovirus globally, with an estimated 400 million infections yearly. Although the effects of DENV infection during pregnancy are unclear, some reported associations include adverse maternal and infant health outcomes, such as prematurity, low birth weight, and miscarriage. In this study, we used IgG enzyme-linked immunosorbent assay (ELISA) to identify mothers who were newly infected with DENV during pregnancy (seronegative antenatal visits, converted seropositive, hence seroconverted, at delivery) by testing samples from a previous study following parasitic infections in a Kenyan cohort of pregnant women. Adverse maternal outcomes, including maternal death, respiratory distress, and stillbirth, and infant health outcomes including developmental age by Ballard score, gestational age by weeks, birth weight, and infant growth were compared between seronegative and seroconverted mothers. Of the total 547 mothers in the original study, 289 maternal-child pairs were eligible for analysis. Using estimates from prior work, we expected approximately 12 women (4%) to have DENV infection in pregnancy; however, 34 mothers (11.8%) were infected during pregnancy. None of the mothers were hospitalized during pregnancy due to severe DENV infection and many likely had asymptomatic seroconversion. Mild or asymptomatic DENV infection during pregnancy was not associated with prematurity, cesarean birth, or adverse maternal pregnancy outcomes, but may be associated with low birth weight, observed for 20.6% of DENV-seroconverted mothers compared to 9.4% of DENV-seronegative mothers. No significant association was observed between DENV during pregnancy and reduced postnatal childhood developmental measures (e.g., height). Mild dengue in pregnancy was not associated with risk factors of socioeconomic status, level of education, bed net use, or maternal age. The larger-than-expected burden of DENV in pregnancy in this coastal Kenyan cohort and the potential observed trends with negative infant and child health outcomes provide evidence that a more powered, dengue-focused study is warranted to better inform policies for maternal, fetal, and child health.