Abstract : BACKGROUND: The primary objectives of the study were to determine the incidence of dengue and outcomes associated with dengue among pregnant women.METHODS: A prospective cohort study was done among 1579 antenatal women in an endemic region in India. Dengue immunoglobulin G (IgG) was tested in 490 women at baseline. Follow-up phone calls and visits were done until 1 week after delivery. In 70 seronegative women, dengue IgG was repeated to identify seroconversion. Incidence proportions, incidence rates, relative risks, attributable risks and population attributable risks along with their 95% confidence intervals (CIs) were calculated. Propensity score methods were used for multivariate assessment of confounding and analysis was repeated with a matched dataset.RESULTS: The seroprevalence of dengue was 30.41% (95% CI 26.45 to 34.59). NS1 positivity detected 78% of dengue in pregnancy. There were no abortions or maternal or newborn deaths. Dengue was significantly associated with delivery complications (adjusted odds ratio [OR] 10.28 [95% CI 4.79 to 22.01]), newborn problems (adjusted OR 5.29 [95% CI 2.89 to 9.70]) and newborn admissions (adjusted OR 5.24 [95% CI 2.36 to 11.65]). Overweight dengue patients had a significantly higher risk of preterm deliveries and higher adverse outcome scores.CONCLUSIONS: Screening of febrile antenatal women for dengue in endemic areas can result in early diagnosis and reduce complications. The dual burden of communicable and non-communicable diseases in pregnancy is a real challenge.