International Prospective Observational Cohort Study of Zika in Infants and Pregnancy

The overall objective of this study was to assess the strength of the association between Zika virus infection (ZIKV) during pregnancy and adverse maternal/fetal outcomes and the risk of vertical transmission. At research sites in ZIKV endemic regions pregnant women were recruited and consented in the first and early second trimesters of pregnancy and then followed through delivery up to 6 weeks post-partum; their infants were followed until at least 1 year of age. Pregnant women with symptomatic ZIKV infection confirmed by presence of ZIKV RNA and/or IgM for ZIKV were also enrolled, regardless of gestational age. Maternal participants were tested monthly for ZIKV infection; additional demographic, clinical, laboratory and environmental data were collected to assess the potential interaction of these variables with ZIKV infection. Delivery outcomes and detailed infant assessments, including physical and neurological outcomes, were obtained.