Risks of Adverse Childhood Outcomes According to Prenatal Time of Exposure to Zika Virus: Assessment in a Cohort Exposed to Zika During an Outbreak in Colombia.

Late gestational exposure to Zika increases the odds of delay in the Bayley-II mental developmental index (MDI) in children with normal baseline neurologic assessments; 9-fold when comparing third and first trimester exposure. Risk of MDI developmental delay increases by 8% for each week of gestational age at time of exposure.

Outcomes of Congenital Zika Virus Infection During an Outbreak in Valle del Cauca, Colombia.

BACKGROUND: Despite increasing information in the literature regarding congenital Zika infection, gaps remain in our knowledge of its clinical manifestations. METHODS: We did a prospective observational study of exposed fetuses and infants whose mothers developed symptomatic and confirmed Zika infection during pregnancy in Valle del Cauca, Colombia. We performed neurological, ophthalmologic and audiologic evaluations, and classified outcomes as possibly or uncertainly related to Zika. Frequencies of outcomes were compared according to the trimester of pregnancy when infection occurred. RESULTS: We evaluated 171 products of gestation including 17 pregnancy losses and 154 patients evaluated postnatally. Ninety (52.6%) pregnancies presented an adverse outcome, 36% possibly related with Zika and the remaining 64% of uncertain relation. Infection in the first trimester had the highest frequencies of adverse outcomes possibly related with Zika compared with the second and third trimesters (39% vs. 12.5% vs. 12%) with risk ratios of adverse outcomes possibly related to Zika in pregnancies infected in the first versus second or third trimester of 3.1 (95% CI: 2.4-4.1) and 3.3 (95% CI: 2.5-4.2), respectively. The frequencies of pregnancy loss and microcephaly were 9.4% and 4.5%, respectively. Auditory and ophthalmic abnormalities possibly related with Zika were present in 3% and 6% of the patients evaluated, respectively. CONCLUSIONS: We observed a high frequency of gestational and neonatal complications in pregnant women who acquired Zika infection, especially in early pregnancy, resulting in a broad spectrum of clinical manifestations. Preventive measures are urgently needed to reduce the clinical burden during future Zika outbreaks.